[
{
"instruction": "\nAnimation in Android with ExampleAnimation is the process of adding a motion effect to any view, image, or text. With the help of an animation, you can add motion or can change the shape of a specific view. Animation in Android is generally used to give your UI a rich look and feel. The animations are basically of three types as follows:\nProperty AnimationView AnimationDrawable Animation1. Property AnimationProperty Animation is one of the robust frameworks which allows animation almost everything. This is one of the powerful and flexible animations which was introduced in Android 3.0. Property animation can be used to add any animation in the CheckBox, RadioButtons, and widgets other than any view.2. View AnimationView Animation can be used to add animation to a specific view to perform tweened animation on views. Tweened animation calculates animation information such as size, rotation, start point, and endpoint. These animations are slower and less flexible. An example of View animation can be used if we want to expand a specific layout in that place we can use View Animation. The example of View Animation can be seen in Expandable RecyclerView.3. Drawable AnimationDrawable Animation is used if you want to animate one image over another. The simple way to understand is to animate drawable is to load the series of drawable one after another to create an animation. A simple example of drawable animation can be seen in many apps Splash screen on apps logo animation.Important Methods of AnimationMethods\nDescription\nstartAnimation()This method will start the animation.clearAnimation()This method will clear the animation running on a specific view.Example of Implementation Android Animation Now we will see the Simple Example to add animations to ImageView. Note that we are going toimplement this project using theJavalanguage.\nStep 1: Create a New ProjectTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Working with the strings.xml fileStrings.xml can be found from the app > res > values > strings.xml. \nBelow is the snippet for the strings.xml file.\nstrings.xml\n GFG App \n BLINK \n ROTATE \n FADE \n MOVE \n SLIDE \n ZOOM \n STOP ANIMATION \n Course Rating \n Course Name \n Step 3: Working with the activity_main.xml fileCreate ImageView in the activity_main.xml along with buttons that will add animation to the view. Navigate to the app > res > layout > activity_main.xml. \nBelow is the code for the activity_main.xml file.activity_main.xml\n \n \n \n \n Step 4: Create 6 different types of animation for ImageViewTo create new animations we have to create a new directory for storing all our animations. Navigate to the app > res > Right-Click on res >> New >> Directory >> Name your directory as \u201canim\u201d. Inside this directory, we will create our animations. For creating a new anim right click on the anim directory >> Animation Resource file and give the name to your file. Below is the code snippet for 6 different animations.\n1. Blink Animation\nblink_animation.xml\n\n \n 2. Fade Animation\nfade_animation.xml\n\n \n \n 3. Move Animation\nmove_animation.xml\n \n 5. Slide Animation\nslide_animation.xml\n\n 6. Zoom Animation\nzoom_animation.xml\n\n \n \n Step 5: Working with the MainActivity.java fileAdd animation to the ImageView by clicking a specific Button. Navigate to the app > java > your apps package name >> MainActivity.java.\nBelow is the implementation of MainActivity file:\nMainActivity.javaimport androidx.appcompat.app.AppCompatActivity;\nimport android.os.Bundle;\nimport android.view.View;\nimport android.view.animation.Animation;\nimport android.view.animation.AnimationUtils;\nimport android.widget.Button;\nimport android.widget.ImageView;public class MainActivity extends AppCompatActivity { // Declare ImageView and Buttons\n ImageView imageView;\n Button blinkBTN, rotateBTN, fadeBTN, moveBTN, slideBTN, zoomBTN, stopBTN; @Override\n protected void onCreate(Bundle savedInstanceState) {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Initialize ImageView and Buttons using their IDs\n imageView = findViewById(R.id.imageview);\n blinkBTN = findViewById(R.id.BTNblink);\n rotateBTN = findViewById(R.id.BTNrotate);\n fadeBTN = findViewById(R.id.BTNfade);\n moveBTN = findViewById(R.id.BTNmove);\n slideBTN = findViewById(R.id.BTNslide);\n zoomBTN = findViewById(R.id.BTNzoom);\n stopBTN = findViewById(R.id.BTNstop); // Set up click listener for blink button to start blink animation\n blinkBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load blink animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.blink_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for rotate button to start rotate animation\n rotateBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load rotate animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.rotate_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for fade button to start fade animation\n fadeBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load fade animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.fade_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for move button to start move animation\n moveBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load move animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.move_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for slide button to start slide animation\n slideBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load slide animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.slide_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for zoom button to start zoom animation\n zoomBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Load zoom animation and start it on the ImageView\n Animation animation = AnimationUtils.loadAnimation(getApplicationContext()\n , R.anim.zoom_animation);\n imageView.startAnimation(animation);\n }\n }); // Set up click listener for stop button to clear any ongoing animation\n stopBTN.setOnClickListener(new View.OnClickListener() {\n @Override\n public void onClick(View v) {\n // Clear the animation on the ImageView\n imageView.clearAnimation();\n }\n });\n }\n}MainActivity.ktpackage com.gfg.animation_androidimport android.os.Bundle\nimport android.view.View\nimport android.widget.Button\nimport android.widget.ImageView\nimport android.view.animation.AnimationUtils\nimport androidx.appcompat.app.AppCompatActivityclass MainActivity : AppCompatActivity() { // Declare variables for ImageView and Buttons\n private lateinit var imageView: ImageView\n private lateinit var blinkBTN: Button\n private lateinit var rotateBTN: Button\n private lateinit var fadeBTN: Button\n private lateinit var moveBTN: Button\n private lateinit var slideBTN: Button\n private lateinit var zoomBTN: Button\n private lateinit var stopBTN: Button override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_main) // Initialize the ImageView and Buttons using their IDs\n imageView = findViewById(R.id.imageview)\n blinkBTN = findViewById(R.id.BTNblink)\n rotateBTN = findViewById(R.id.BTNrotate)\n fadeBTN = findViewById(R.id.BTNfade)\n moveBTN = findViewById(R.id.BTNmove)\n slideBTN = findViewById(R.id.BTNslide)\n zoomBTN = findViewById(R.id.BTNzoom)\n stopBTN = findViewById(R.id.BTNstop) // Set up click listeners for each button to start corresponding animations\n createAnimation(blinkBTN, R.anim.blink_animation)\n createAnimation(rotateBTN, R.anim.rotate_animation)\n createAnimation(fadeBTN, R.anim.fade_animation)\n createAnimation(moveBTN, R.anim.move_animation)\n createAnimation(slideBTN, R.anim.slide_animation)\n createAnimation(zoomBTN, R.anim.zoom_animation) // Set up click listener for stop button to clear any ongoing animation\n stopBTN.setOnClickListener {\n imageView.clearAnimation()\n }\n } // Function to set up an animation for a given view and animation resource ID\n private fun createAnimation(view: View, animationResId: Int) {\n view.setOnClickListener {\n // Load the animation from the specified resource ID\n val animation = AnimationUtils.loadAnimation(this, animationResId)\n // Start the animation on the ImageView\n imageView.startAnimation(animation)\n }\n }\n}Note: Drawables and strings can be found in the drawable folder and strings.xml file. Drawables can be found from the app > res > drawable.\nOutput:\nhttps://media.geeksforgeeks.org/wp-content/uploads/20201126131135/Screenrecorder-2020-11-26-12-51-05-314.mp4Note :To access the full android application using Pie chat check this repository:Animation in Android ApplicationClick Here to Learn How to Create Android Application",
"input": "",
"output": "id, Menu is an important part of the UI component which is used to provide some common functionality around the application. With the help of menu, users can experience a smooth and consistent experience throughout the application. In order to use menu, we should define it in a separate XML file and use that file in our application based on our requirements. Also, we can use menu APIs to represent user actions and other options in our android application activities.\nHow to define Menu in XML File?\nAndroid Studio provides a standard XML format for the type of menus to define menu items. We can simply define the menu and all its items in XML menu resource instead of building the menu in the code and also load menu resource as menu object in the activity or fragment used in our android application. Here, we should create a new folder menu inside of our project directory (res/menu) to define the menu and also add a new XML file to build the menu with the following elements. Below is the example of defining a menu in the XML file (menu_example.xml).\nWay to create menu directory and menu resource file:\nTo create the menu directory just right-click on res folder and navigate to res->New->Android Resource Directory. Give resource directory name as menu and resource type also menu. one directory will be created under res folder.\nTo create xml resource file simply right-click on menu folder and navigate to New->Menu Resource File. Give name of file as menu_example. One menu_example.xml file will be created under menu folder.XML \n\n It is the root element that helps in defining Menu in XML file and it also holds multiple elements.\n- It is used to create a single item in the menu. It also contains nested
element in order to create a submenu.\n It is optional and invisible for - elements to categorize the menu items so they can share properties like active state, and visibility.activity_main.xml\nIf we want to add a submenu in menu item, then we need to add a
element as the child of an - . Below is the example of defining a submenu in a menu item.XML \n
\n- \n\n
\n \n \n Android Different Types of Menus\nIn android, we have three types of Menus available to define a set of options and actions in our android applications. The Menus in android applications are the following:Android Options Menu\nAndroid Context Menu\nAndroid Popup MenuAndroid Options Menu is a primary collection of menu items in an android application and is useful for actions that have a global impact on the searching application. Android Context Menu is a floating menu that only appears when the user clicks for a long time on an element and is useful for elements that affect the selected content or context frame. Android Popup Menu displays a list of items in a vertical list which presents the view that invoked the menu and is useful to provide an overflow of actions related to specific content."
},
{
"instruction": "id, Menu is an important part of the UI component which is used to provide some common functionality around the application. With the help of menu, users can experience a smooth and consistent experience throughout the application. In order to use menu, we should define it in a separate XML file and use that file in our application based on our requirements. Also, we can use menu APIs to represent user actions and other options in our android application activities.\nHow to define Menu in XML File?\nAndroid Studio provides a standard XML format for the type of menus to define menu items. We can simply define the menu and all its items in XML menu resource instead of building the menu in the code and also load menu resource as menu object in the activity or fragment used in our android application. Here, we should create a new folder menu inside of our project directory (res/menu) to define the menu and also add a new XML file to build the menu with the following elements. Below is the example of defining a menu in the XML file (menu_example.xml).\nWay to create menu directory and menu resource file:\nTo create the menu directory just right-click on res folder and navigate to res->New->Android Resource Directory. Give resource directory name as menu and resource type also menu. one directory will be created under res folder.\nTo create xml resource file simply right-click on menu folder and navigate to New->Menu Resource File. Give name of file as menu_example. One menu_example.xml file will be created under menu folder.XML \n\n It is the root element that helps in defining Menu in XML file and it also holds multiple elements.\n- It is used to create a single item in the menu. It also contains nested
element in order to create a submenu.\n It is optional and invisible for - elements to categorize the menu items so they can share properties like active state, and visibility.activity_main.xml\nIf we want to add a submenu in menu item, then we need to add a
element as the child of an - . Below is the example of defining a submenu in a menu item.XML \n
\n- \n\n
\n \n \n Android Different Types of Menus\nIn android, we have three types of Menus available to define a set of options and actions in our android applications. The Menus in android applications are the following:Android Options Menu\nAndroid Context Menu\nAndroid Popup MenuAndroid Options Menu is a primary collection of menu items in an android application and is useful for actions that have a global impact on the searching application. Android Context Menu is a floating menu that only appears when the user clicks for a long time on an element and is useful for elements that affect the selected content or context frame. Android Popup Menu displays a list of items in a vertical list which presents the view that invoked the menu and is useful to provide an overflow of actions related to specific content.",
"input": "",
"output": "nto an Android ApplicationA Pie Chart is a circular statistical graphic, which is divided into slices to illustrate numerical proportions. It depicts a special chart that uses \u201cpie slices\u201d, where each sector shows the relative sizes of data. A circular chart cuts in the form of radii into segments describing relative frequencies or magnitude also known as a circle graph. A pie chart represents numbers in percentages, and the total sum of all segments needs to equal 100%. \nHere is the Final Application which will be created.\nhttps://media.geeksforgeeks.org/wp-content/uploads/20240521115249/Pie-Chart-Android-Java.mp4\nStep-by-Step Implementation of Pie Chart in Android ApplicationSo let\u2019s see the steps to add a Pie Chart into an Android app. \nStep 1: Opening/Creating a New ProjectTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. \nNote: SelectJavaas the programming language.\nBy default, there will be two files activity_main.xml and MainActivity.java.\nStep 2: Before going to the Coding Section first you have to do some Pre-Task. 1. Navigate to Gradle Scripts->build.gradle (Module: app) Add the dependencies mentioned below:dependencies{ // For Card view implementation 'androidx.cardview:cardview:1.0.0' // Chart and graph library implementation 'com.github.blackfizz:eazegraph:1.2.2@aar' implementation 'com.nineoldandroids:library:2.4.0'}After Importing following dependencies and click the \u201csync Now\u201d on the above pop up. \n2. Naviagate to app->res->values->colors.xml: Add and Set the colors for your app. \ncolors.xml\n\n #024265 \n #024265 \n #05af9b #fb7268 \n #ededf2 \n #E3E0E0 #FFA726 \n #66BB6A \n #EF5350 \n #29B6F6 Step 3: Designing the Layout of the ApplicationBelow is the code for the xml file. \nactivity_main.xml After using this code in .xml file, the Layout will be like:Step 4: Changes in the MainActivity File to Add Functionality in the Application Open the MainActivity.java file there within the class, first of all create the object of TextView class and the pie chart class. \nJava // Create the object of TextView and PieChart class\n TextView tvR, tvPython, tvCPP, tvJava;\n PieChart pieChart;Secondly inside onCreate() method, we have to link those objects with their respective id\u2019s that we have given in .XML file. \nJava // Link those objects with their respective\n // id's that we have given in .XML file\n tvR = findViewById(R.id.tvR);\n tvPython = findViewById(R.id.tvPython);\n tvCPP = findViewById(R.id.tvCPP);\n tvJava = findViewById(R.id.tvJava);\n pieChart = findViewById(R.id.piechart);Create a private void setData() method outside onCreate() method and define it.Inside setData() method the most important task is going to happen that is how we set the data in the text file and as well as on the piechart. First of all inside setData() method set the percentage of language used in their respective text view. \nJava // Set the percentage of language used\n tvR.setText(Integer.toString(40));\n tvPython.setText(Integer.toString(30));\n tvCPP.setText(Integer.toString(5));\n tvJava.setText(Integer.toString(25));And then set this data to the pie chart and also set their respective colors using addPieSlice() method. \nJava // Set the data and color to the pie chart\n pieChart.addPieSlice(new PieModel(\"R\",Integer.parseInt(tvR.getText().toString()),\n Color.parseColor(\"#FFA726\")));\n \n pieChart.addPieSlice(new PieModel(\"Python\",Integer.parseInt(tvPython.getText().toString()),\n Color.parseColor(\"#66BB6A\"))); pieChart.addPieSlice(new PieModel(\"C++\",Integer.parseInt(tvCPP.getText().toString()),\n Color.parseColor(\"#EF5350\"))); pieChart.addPieSlice(new PieModel(\"Java\",Integer.parseInt(tvJava.getText().toString()),\n Color.parseColor(\"#29B6F6\")));For better look animate the piechart using startAnimation(). \nJava // To animate the pie chart\n pieChart.startAnimation();At last invoke the setData() method inside onCreate() method. \nBelow is the complete code for MainActivity.java file: \nMainActivity.javapackage com.example.final_pie_chart_java;// Import the required libraries\nimport androidx.appcompat.app.AppCompatActivity;\nimport android.graphics.Color;\nimport android.os.Bundle;\nimport android.widget.TextView;\nimport org.eazegraph.lib.charts.PieChart;\nimport org.eazegraph.lib.models.PieModel;public class MainActivity\n extends AppCompatActivity { // Create the object of TextView\n // and PieChart class\n TextView tvR, tvPython, tvCPP, tvJava;\n PieChart pieChart; @Override\n protected void onCreate(Bundle savedInstanceState)\n {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Link those objects with their\n // respective id's that\n // we have given in .XML file\n tvR = findViewById(R.id.tvR);\n tvPython = findViewById(R.id.tvPython);\n tvCPP = findViewById(R.id.tvCPP);\n tvJava = findViewById(R.id.tvJava);\n pieChart = findViewById(R.id.piechart); // Creating a method setData()\n // to set the text in text view and pie chart\n setData();\n } private void setData()\n { // Set the percentage of language used\n tvR.setText(Integer.toString(40));\n tvPython.setText(Integer.toString(30));\n tvCPP.setText(Integer.toString(5));\n tvJava.setText(Integer.toString(25)); // Set the data and color to the pie chart\n pieChart.addPieSlice(\n new PieModel(\n \"R\",\n Integer.parseInt(tvR.getText().toString()),\n Color.parseColor(\"#FFA726\")));\n pieChart.addPieSlice(\n new PieModel(\n \"Python\",\n Integer.parseInt(tvPython.getText().toString()),\n Color.parseColor(\"#66BB6A\")));\n pieChart.addPieSlice(\n new PieModel(\n \"C++\",\n Integer.parseInt(tvCPP.getText().toString()),\n Color.parseColor(\"#EF5350\")));\n pieChart.addPieSlice(\n new PieModel(\n \"Java\",\n Integer.parseInt(tvJava.getText().toString()),\n Color.parseColor(\"#29B6F6\"))); // To animate the pie chart\n pieChart.startAnimation();\n }\n}Output:Run The Application, Check this article Android | Running your first Android app as the reference.Note : To access the full android application using Pie chat check this repository: Pie Chart Android Application\nClick Here to Learn How to Create Android Application\n"
},
{
"instruction": "nto an Android ApplicationA Pie Chart is a circular statistical graphic, which is divided into slices to illustrate numerical proportions. It depicts a special chart that uses \u201cpie slices\u201d, where each sector shows the relative sizes of data. A circular chart cuts in the form of radii into segments describing relative frequencies or magnitude also known as a circle graph. A pie chart represents numbers in percentages, and the total sum of all segments needs to equal 100%. \nHere is the Final Application which will be created.\nhttps://media.geeksforgeeks.org/wp-content/uploads/20240521115249/Pie-Chart-Android-Java.mp4\nStep-by-Step Implementation of Pie Chart in Android ApplicationSo let\u2019s see the steps to add a Pie Chart into an Android app. \nStep 1: Opening/Creating a New ProjectTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. \nNote: SelectJavaas the programming language.\nBy default, there will be two files activity_main.xml and MainActivity.java.\nStep 2: Before going to the Coding Section first you have to do some Pre-Task. 1. Navigate to Gradle Scripts->build.gradle (Module: app) Add the dependencies mentioned below:dependencies{ // For Card view implementation 'androidx.cardview:cardview:1.0.0' // Chart and graph library implementation 'com.github.blackfizz:eazegraph:1.2.2@aar' implementation 'com.nineoldandroids:library:2.4.0'}After Importing following dependencies and click the \u201csync Now\u201d on the above pop up. \n2. Naviagate to app->res->values->colors.xml: Add and Set the colors for your app. \ncolors.xml\n\n #024265 \n #024265 \n #05af9b #fb7268 \n #ededf2 \n #E3E0E0 #FFA726 \n #66BB6A \n #EF5350 \n #29B6F6 Step 3: Designing the Layout of the ApplicationBelow is the code for the xml file. \nactivity_main.xml After using this code in .xml file, the Layout will be like:Step 4: Changes in the MainActivity File to Add Functionality in the Application Open the MainActivity.java file there within the class, first of all create the object of TextView class and the pie chart class. \nJava // Create the object of TextView and PieChart class\n TextView tvR, tvPython, tvCPP, tvJava;\n PieChart pieChart;Secondly inside onCreate() method, we have to link those objects with their respective id\u2019s that we have given in .XML file. \nJava // Link those objects with their respective\n // id's that we have given in .XML file\n tvR = findViewById(R.id.tvR);\n tvPython = findViewById(R.id.tvPython);\n tvCPP = findViewById(R.id.tvCPP);\n tvJava = findViewById(R.id.tvJava);\n pieChart = findViewById(R.id.piechart);Create a private void setData() method outside onCreate() method and define it.Inside setData() method the most important task is going to happen that is how we set the data in the text file and as well as on the piechart. First of all inside setData() method set the percentage of language used in their respective text view. \nJava // Set the percentage of language used\n tvR.setText(Integer.toString(40));\n tvPython.setText(Integer.toString(30));\n tvCPP.setText(Integer.toString(5));\n tvJava.setText(Integer.toString(25));And then set this data to the pie chart and also set their respective colors using addPieSlice() method. \nJava // Set the data and color to the pie chart\n pieChart.addPieSlice(new PieModel(\"R\",Integer.parseInt(tvR.getText().toString()),\n Color.parseColor(\"#FFA726\")));\n \n pieChart.addPieSlice(new PieModel(\"Python\",Integer.parseInt(tvPython.getText().toString()),\n Color.parseColor(\"#66BB6A\"))); pieChart.addPieSlice(new PieModel(\"C++\",Integer.parseInt(tvCPP.getText().toString()),\n Color.parseColor(\"#EF5350\"))); pieChart.addPieSlice(new PieModel(\"Java\",Integer.parseInt(tvJava.getText().toString()),\n Color.parseColor(\"#29B6F6\")));For better look animate the piechart using startAnimation(). \nJava // To animate the pie chart\n pieChart.startAnimation();At last invoke the setData() method inside onCreate() method. \nBelow is the complete code for MainActivity.java file: \nMainActivity.javapackage com.example.final_pie_chart_java;// Import the required libraries\nimport androidx.appcompat.app.AppCompatActivity;\nimport android.graphics.Color;\nimport android.os.Bundle;\nimport android.widget.TextView;\nimport org.eazegraph.lib.charts.PieChart;\nimport org.eazegraph.lib.models.PieModel;public class MainActivity\n extends AppCompatActivity { // Create the object of TextView\n // and PieChart class\n TextView tvR, tvPython, tvCPP, tvJava;\n PieChart pieChart; @Override\n protected void onCreate(Bundle savedInstanceState)\n {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Link those objects with their\n // respective id's that\n // we have given in .XML file\n tvR = findViewById(R.id.tvR);\n tvPython = findViewById(R.id.tvPython);\n tvCPP = findViewById(R.id.tvCPP);\n tvJava = findViewById(R.id.tvJava);\n pieChart = findViewById(R.id.piechart); // Creating a method setData()\n // to set the text in text view and pie chart\n setData();\n } private void setData()\n { // Set the percentage of language used\n tvR.setText(Integer.toString(40));\n tvPython.setText(Integer.toString(30));\n tvCPP.setText(Integer.toString(5));\n tvJava.setText(Integer.toString(25)); // Set the data and color to the pie chart\n pieChart.addPieSlice(\n new PieModel(\n \"R\",\n Integer.parseInt(tvR.getText().toString()),\n Color.parseColor(\"#FFA726\")));\n pieChart.addPieSlice(\n new PieModel(\n \"Python\",\n Integer.parseInt(tvPython.getText().toString()),\n Color.parseColor(\"#66BB6A\")));\n pieChart.addPieSlice(\n new PieModel(\n \"C++\",\n Integer.parseInt(tvCPP.getText().toString()),\n Color.parseColor(\"#EF5350\")));\n pieChart.addPieSlice(\n new PieModel(\n \"Java\",\n Integer.parseInt(tvJava.getText().toString()),\n Color.parseColor(\"#29B6F6\"))); // To animate the pie chart\n pieChart.startAnimation();\n }\n}Output:Run The Application, Check this article Android | Running your first Android app as the reference.Note : To access the full android application using Pie chat check this repository: Pie Chart Android Application\nClick Here to Learn How to Create Android Application\n",
"input": "",
"output": "Google has officially announced Kotlin as a recommended language for Android Development and that\u2019s why so many developers are switching from Java to Kotlin for Android development. So day by day new APIs are been introduced in Android by the Google Team and which are available in newer versions of Android devices as well. So Desugaring is also one of the important features in Android that we should enable in our app which will allow our apps to work in lower API levels as well. So in this article, we will learn about Desugaring.What is Desugaring?\nWhy we need Desugaring?\nPractical Implementation of Desugaring.\nWhat\u2019s happening under the hood?What is Desugaring?\nAndroid devices are getting optimized day by day. So many features in Android for users as well as developers are getting optimized. When any operating system of Android is developed, it is delivered with so many Java classes which provides support to different apps in user\u2019s devices for various functionalities such as time, date, and many other features. Now if we consider time API it was introduced in API level 26 and the apps which use this API will crash on the lower API level devices such as Marshmallow and lower versions. So in this case to avoid the app crashes Desugaring comes into play. It allows lower API levels to work with new JAVA libraries.\nWhy We Need Desugaring?\nSuppose for example we are using a new time API which is introduced in API level 26 and we have used this API of time in our app. This app will work perfectly for API level 26 and above but when we will install this app on the lower API level let suppose API level 23 or lower than that then our app will crash because our device OS supports the features provided from API level 23 and we are using features of API level 26 which will not work. So for avoiding this app crashes and to support the new features from API level 26 into API level 23 we have to add Desugaring in our app.\nPractical Implementation of Desugaring in Android\nWhen we are using features provided by API level 26 in the devices lower than API level 26 then the app will crash. In the apps with a lower API level, we will get to see an error as NoClassDefFoundError. So to resolve this error we have to enable Desugaring in Android.\nStep by Step implementation of Desugaring\nStep 1: Navigate to the Gradle Scripts > build.gradle(:app) and inside your dependencies section add the dependency given belowcoreLibraryDesugaring \u2018com.android.tools:desugar_jdk_libs:1.0.9\u2019Now after adding this dependency you have to add the below line in your compileOptions part of your codecoreLibraryDesugaringEnabled trueStep 2: Now we have to enable multiDex in our app for that navigate to your Gradle file inside that in the section of defaultConfig section add the below line asmultiDexEnabled trueAnd sync your project. After the successful project sync, Desugaring has been implemented in our app and now we will not get to see NoClassDefFoundError in the devices with lower API levels. The complete code for the Gradle file is given below:Kotlin plugins { \nid 'com.android.application'\nid 'kotlin-android'\n} android { \ncompileSdkVersion 30\nbuildToolsVersion \"30.0.2\"defaultConfig { \napplicationId \"com.gtappdevelopers.desugaring\"\nminSdkVersion 19\nmultiDexEnabled true\ntargetSdkVersion 30\nversionCode 1\nversionName \"1.0\"testInstrumentationRunner \"androidx.test.runner.AndroidJUnitRunner\"\n} buildTypes { \nrelease { \nminifyEnabled false\nproguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'\n} \n} \ncompileOptions { \nsourceCompatibility JavaVersion.VERSION_1_8 \ntargetCompatibility JavaVersion.VERSION_1_8 \ncoreLibraryDesugaringEnabled true\n} \nkotlinOptions { \njvmTarget = '1.8'\n} \n} dependencies { implementation \"org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version\"\nimplementation 'androidx.core:core-ktx:1.3.2'\ncoreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.9'\nimplementation 'androidx.appcompat:appcompat:1.2.0'\nimplementation 'com.google.android.material:material:1.2.1'\nimplementation 'androidx.constraintlayout:constraintlayout:2.0.4'\ntestImplementation 'junit:junit:4.+'\nandroidTestImplementation 'androidx.test.ext:junit:1.1.2'\nandroidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'\n}What\u2019s Happening Under the Hood?\nSo what is happening here and how the java classes which were missing suddenly appear here. This is because of D8 and R8 tools. Previously for converting your app\u2019s code in dex code we have to use Proguard but to reduce compile-time and to reduce app size the new R8 tool was introduced. This R8 tool provides the support of missing Java classes. When this tool converts your app\u2019s code into dex code it also adds dex code of new java libraries which are then added in the APK. You can get a clear idea about this process from the below diagram.In this way, Desugaring works and it provides backward compatibility for new Java libraries in the devices with lower API levels. "
},
{
"instruction": "Google has officially announced Kotlin as a recommended language for Android Development and that\u2019s why so many developers are switching from Java to Kotlin for Android development. So day by day new APIs are been introduced in Android by the Google Team and which are available in newer versions of Android devices as well. So Desugaring is also one of the important features in Android that we should enable in our app which will allow our apps to work in lower API levels as well. So in this article, we will learn about Desugaring.What is Desugaring?\nWhy we need Desugaring?\nPractical Implementation of Desugaring.\nWhat\u2019s happening under the hood?What is Desugaring?\nAndroid devices are getting optimized day by day. So many features in Android for users as well as developers are getting optimized. When any operating system of Android is developed, it is delivered with so many Java classes which provides support to different apps in user\u2019s devices for various functionalities such as time, date, and many other features. Now if we consider time API it was introduced in API level 26 and the apps which use this API will crash on the lower API level devices such as Marshmallow and lower versions. So in this case to avoid the app crashes Desugaring comes into play. It allows lower API levels to work with new JAVA libraries.\nWhy We Need Desugaring?\nSuppose for example we are using a new time API which is introduced in API level 26 and we have used this API of time in our app. This app will work perfectly for API level 26 and above but when we will install this app on the lower API level let suppose API level 23 or lower than that then our app will crash because our device OS supports the features provided from API level 23 and we are using features of API level 26 which will not work. So for avoiding this app crashes and to support the new features from API level 26 into API level 23 we have to add Desugaring in our app.\nPractical Implementation of Desugaring in Android\nWhen we are using features provided by API level 26 in the devices lower than API level 26 then the app will crash. In the apps with a lower API level, we will get to see an error as NoClassDefFoundError. So to resolve this error we have to enable Desugaring in Android.\nStep by Step implementation of Desugaring\nStep 1: Navigate to the Gradle Scripts > build.gradle(:app) and inside your dependencies section add the dependency given belowcoreLibraryDesugaring \u2018com.android.tools:desugar_jdk_libs:1.0.9\u2019Now after adding this dependency you have to add the below line in your compileOptions part of your codecoreLibraryDesugaringEnabled trueStep 2: Now we have to enable multiDex in our app for that navigate to your Gradle file inside that in the section of defaultConfig section add the below line asmultiDexEnabled trueAnd sync your project. After the successful project sync, Desugaring has been implemented in our app and now we will not get to see NoClassDefFoundError in the devices with lower API levels. The complete code for the Gradle file is given below:Kotlin plugins { \nid 'com.android.application'\nid 'kotlin-android'\n} android { \ncompileSdkVersion 30\nbuildToolsVersion \"30.0.2\"defaultConfig { \napplicationId \"com.gtappdevelopers.desugaring\"\nminSdkVersion 19\nmultiDexEnabled true\ntargetSdkVersion 30\nversionCode 1\nversionName \"1.0\"testInstrumentationRunner \"androidx.test.runner.AndroidJUnitRunner\"\n} buildTypes { \nrelease { \nminifyEnabled false\nproguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'\n} \n} \ncompileOptions { \nsourceCompatibility JavaVersion.VERSION_1_8 \ntargetCompatibility JavaVersion.VERSION_1_8 \ncoreLibraryDesugaringEnabled true\n} \nkotlinOptions { \njvmTarget = '1.8'\n} \n} dependencies { implementation \"org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version\"\nimplementation 'androidx.core:core-ktx:1.3.2'\ncoreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.9'\nimplementation 'androidx.appcompat:appcompat:1.2.0'\nimplementation 'com.google.android.material:material:1.2.1'\nimplementation 'androidx.constraintlayout:constraintlayout:2.0.4'\ntestImplementation 'junit:junit:4.+'\nandroidTestImplementation 'androidx.test.ext:junit:1.1.2'\nandroidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'\n}What\u2019s Happening Under the Hood?\nSo what is happening here and how the java classes which were missing suddenly appear here. This is because of D8 and R8 tools. Previously for converting your app\u2019s code in dex code we have to use Proguard but to reduce compile-time and to reduce app size the new R8 tool was introduced. This R8 tool provides the support of missing Java classes. When this tool converts your app\u2019s code into dex code it also adds dex code of new java libraries which are then added in the APK. You can get a clear idea about this process from the below diagram.In this way, Desugaring works and it provides backward compatibility for new Java libraries in the devices with lower API levels. ",
"input": "",
"output": "droidSlider Date Picker is one of the most popular features that we see in most apps. We can get to see this Slider date picker in most of the travel planning applications, Ticket booking services, and many more. Using Slider date Picker makes it efficient to pick the date. In this article, we are going to see how to implement Slider Date Picker in Android. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Applications of Slider Date PickerThe most common application of this Slider date picker is it is used in most travel planning apps.\nThis Date Picker can also be seen in Ticket Booking services.\nYou can get to see this Slider Date Picker in the exam form filling application.Attributes of Slider Date PickerAttributesDescription.setStartDate()\nTo set the starting Date of the Calendar..setEndDate()\nTo set the ending Date of the Calendar..setThemeColor()\nTo set the theme Color..setHeaderTextColor()\nTo set the header text Color..setHeaderDateFormat()\nTo set the Date Format..setShowYear()\nTo show the current year..setCancelText()\nTo cancel text..setConfirmText()\nTo confirm text..setPreselectedDate()\nTo select today\u2019s date.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add dependency and JitPack Repository\nNavigate to the Gradle Scripts > build.gradle(Module:app) and add the below dependency in the dependencies section. implementation \u2018com.github.niwattep:material-slide-date-picker:v2.0.0\u2019Add the JitPack repository to your build file. Add it to your root build.gradle at the end of repositories inside the allprojects{ } section.allprojects {\nrepositories {\n \u2026\n maven { url \u201chttps://jitpack.io\u201d }\n }\n}After adding this dependency sync your project and now we will move towards its implementation. \nStep 3: Create a new Slider Date Picker in your activity_main.xml file\nNavigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.XML \n\n\n The above code of DatePicker can be seen in android application like thisAndroid DatePicker with Spinner mode\nWe can also show the DatePicker in spinner format like selecting the day, month and year separately, by using android:datePickerMode attribute and set android:calendarViewShown=\u201dfalse\u201d, otherwise both spinner and calendar can be seen simultaneously.XML The above code of DatePicker can be seen in android application like thisDifferent attributes of DatePicker control \u2013XML Attributes\nDescriptionandroid:id\nUsed to uniquely identify the control.android:datePickerMode\nUsed to specify the mode of datepicker(spinner or calendar)android:calendarTextColor\nUsed to specify the color of the text.android:calendarViewShown\nUsed to specify whether view of the calendar is shown or not.android:background\nUsed to set background color of the Text View.android:padding\nUsed to set the padding from left, right, top and bottom.To use Calendar DatePicker in activity_main.xml\nIn this file, we will add the DatePicker and Button widget and set their attributes so that it can be accessed in the kotlin file.XML \n To use Spinner DatePicker in activity_main.xml\nIn this file, we will add the DatePicker and Button widget and set their attributes so that it can be accessed in the kotlin file.XML \n Modify the strings.xml file to add the string-array\nHere, we will specify the name of the activity.XML \nDatePickerInKotlin \n Access the DatePicker in MainActivity.kt file\nFirst of all, we declare a variable datePicker to access the DatePicker widget from the XML layout.\nval datePicker = findViewById(R.id.date_Picker)\nthen, we declare another variable today to get the current get like this.\nval today = Calendar.getInstance()\n datePicker.init(today.get(Calendar.YEAR), today.get(Calendar.MONTH),\n today.get(Calendar.DAY_OF_MONTH)\nTo display the selected date from the calendar we will use\n { view, year, month, day ->\n val month = month + 1\n val msg = \"You Selected: $day/$month/$year\"\n Toast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show()\n }\nWe are familiar with further activities in previous articles like accessing button and set OnClickListener etc.Kotlin package com.geeksforgeeks.myfirstkotlinapp import androidx.appcompat.app.AppCompatActivity \nimport android.os.Bundle \nimport android.widget.* \nimport java.util.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) val datePicker = findViewById(R.id.date_Picker) \nval today = Calendar.getInstance() \ndatePicker.init(today.get(Calendar.YEAR), today.get(Calendar.MONTH), \ntoday.get(Calendar.DAY_OF_MONTH) ) { view, year, month, day -> \nval month = month + 1\nval msg = \"You Selected: $day/$month/$year\"\nToast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show() \n} \n} \n} AndroidManifest.xml fileXML \n \n \n \n \n \n Run as Emulator:"
},
{
"instruction": "ndroid DatePicker is a user interface control which is used to select the date by day, month and year in our android application. DatePicker is used to ensure that the users will select a valid date.In android DatePicker having two modes, first one to show the complete calendar and second one shows the dates in spinner view.We can create a DatePicker control in two ways either manually in XML file or create it in Activity file programmatically.First we create a new project by following the below steps:Click on File, then New => New Project.\nAfter that include the Kotlin support and click on next.\nSelect the minimum SDK as per convenience and click next button.\nThen select the Empty activity => next => finish.Android DatePicker with Calendar mode\nWe can use android:datePickerMode to show only calendar view. In the below example, we are using the DatePicker in Calendar mode.XML The above code of DatePicker can be seen in android application like thisAndroid DatePicker with Spinner mode\nWe can also show the DatePicker in spinner format like selecting the day, month and year separately, by using android:datePickerMode attribute and set android:calendarViewShown=\u201dfalse\u201d, otherwise both spinner and calendar can be seen simultaneously.XML The above code of DatePicker can be seen in android application like thisDifferent attributes of DatePicker control \u2013XML Attributes\nDescriptionandroid:id\nUsed to uniquely identify the control.android:datePickerMode\nUsed to specify the mode of datepicker(spinner or calendar)android:calendarTextColor\nUsed to specify the color of the text.android:calendarViewShown\nUsed to specify whether view of the calendar is shown or not.android:background\nUsed to set background color of the Text View.android:padding\nUsed to set the padding from left, right, top and bottom.To use Calendar DatePicker in activity_main.xml\nIn this file, we will add the DatePicker and Button widget and set their attributes so that it can be accessed in the kotlin file.XML \n To use Spinner DatePicker in activity_main.xml\nIn this file, we will add the DatePicker and Button widget and set their attributes so that it can be accessed in the kotlin file.XML \n Modify the strings.xml file to add the string-array\nHere, we will specify the name of the activity.XML \nDatePickerInKotlin \n Access the DatePicker in MainActivity.kt file\nFirst of all, we declare a variable datePicker to access the DatePicker widget from the XML layout.\nval datePicker = findViewById(R.id.date_Picker)\nthen, we declare another variable today to get the current get like this.\nval today = Calendar.getInstance()\n datePicker.init(today.get(Calendar.YEAR), today.get(Calendar.MONTH),\n today.get(Calendar.DAY_OF_MONTH)\nTo display the selected date from the calendar we will use\n { view, year, month, day ->\n val month = month + 1\n val msg = \"You Selected: $day/$month/$year\"\n Toast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show()\n }\nWe are familiar with further activities in previous articles like accessing button and set OnClickListener etc.Kotlin package com.geeksforgeeks.myfirstkotlinapp import androidx.appcompat.app.AppCompatActivity \nimport android.os.Bundle \nimport android.widget.* \nimport java.util.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) val datePicker = findViewById(R.id.date_Picker) \nval today = Calendar.getInstance() \ndatePicker.init(today.get(Calendar.YEAR), today.get(Calendar.MONTH), \ntoday.get(Calendar.DAY_OF_MONTH) ) { view, year, month, day -> \nval month = month + 1\nval msg = \"You Selected: $day/$month/$year\"\nToast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show() \n} \n} \n} AndroidManifest.xml fileXML \n \n \n \n \n \n Run as Emulator:",
"input": "",
"output": "in Android?In this article, WaveLineView is implemented in android. WaveLineView provides us with a very beautiful UI. It can be used when the user has to wait for some time. WaveLineView makes our layout very attractive and hence enhancing the user experience of the app. WaveLineView provide two methods startAnim() and stopAnim(). WaveLineView can be used wherever the developer wants the user to wait for some time. Also, Progress Bar can be used instead of this but because of its unique UI, it will attract users and hence users wait for enough time. It also provides full control to Developers as they can customize it according to the requirements.\nStep By Step Implementation\nStep 1: Create a New Project in Android Studio\nTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android.\nStep 2: Add the Required Dependencies\nNavigate to the Gradle Scripts > build.gradle(Module:app) and Add the Below Dependency in the Dependencies section.\nimplementation 'com.github.Jay-Goo:WaveLineView:v1.0.4'\nAdd the Support Library in your settings.gradle File. This library Jitpack is a novel package repository. It is made for JVM so that any library which is present in Github and Bitbucket can be directly used in the application.\ndependencyResolutionManagement {\n repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)\n repositories {\n google()\n mavenCentral()\n \n // add the following\n maven { url \"https://jitpack.io\" }\n }\n}\nAfter adding this Dependency, Sync the Project and now we will move towards its implementation.\nStep 3: Working with the XML Files\nNext, go to the activity_main.xml file, which represents the UI of the project. Below is the code for theactivity_main.xml file. Comments are added inside the code to understand the code in more detail. In this file, we add WaveLineView to the layout.XML \n(R.id.waveLineView)\nwaveLineView.startAnim()\n}\n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20200709215403/Record_2020-07-09-21-49-10_6a33b8dc17ce0e45bec163fe538b18f01.mp4"
},
{
"instruction": "in Android?In this article, WaveLineView is implemented in android. WaveLineView provides us with a very beautiful UI. It can be used when the user has to wait for some time. WaveLineView makes our layout very attractive and hence enhancing the user experience of the app. WaveLineView provide two methods startAnim() and stopAnim(). WaveLineView can be used wherever the developer wants the user to wait for some time. Also, Progress Bar can be used instead of this but because of its unique UI, it will attract users and hence users wait for enough time. It also provides full control to Developers as they can customize it according to the requirements.\nStep By Step Implementation\nStep 1: Create a New Project in Android Studio\nTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android.\nStep 2: Add the Required Dependencies\nNavigate to the Gradle Scripts > build.gradle(Module:app) and Add the Below Dependency in the Dependencies section.\nimplementation 'com.github.Jay-Goo:WaveLineView:v1.0.4'\nAdd the Support Library in your settings.gradle File. This library Jitpack is a novel package repository. It is made for JVM so that any library which is present in Github and Bitbucket can be directly used in the application.\ndependencyResolutionManagement {\n repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)\n repositories {\n google()\n mavenCentral()\n \n // add the following\n maven { url \"https://jitpack.io\" }\n }\n}\nAfter adding this Dependency, Sync the Project and now we will move towards its implementation.\nStep 3: Working with the XML Files\nNext, go to the activity_main.xml file, which represents the UI of the project. Below is the code for theactivity_main.xml file. Comments are added inside the code to understand the code in more detail. In this file, we add WaveLineView to the layout.XML \n(R.id.waveLineView)\nwaveLineView.startAnim()\n}\n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20200709215403/Record_2020-07-09-21-49-10_6a33b8dc17ce0e45bec163fe538b18f01.mp4",
"input": "",
"output": "PlayerView Library in Android?If you are looking to display YouTube videos inside your app without redirecting your user from your app to YouTube then this library is very helpful for you to use. With the help of this library, you can simply play videos from YouTube with the help of a video id inside your app itself without redirecting your user to YouTube. Now we will see the implementation of this library in our Android App. We are going toimplement this project using both Java and Kotlin Programming Language for Android.\nStep by Step Implementation\nStep 1: Create a New Project in Android Studio\nTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android.\nStep 2: Add the JAR File inside the Libs Folder in Android Studio\nDownload the JAR file from this link. To add this file open your android project in \u201cProject\u201d mode as shown in the below image.Then go to Your Project Name > app > libs and right-click on it and paste the downloaded JAR files. You may also refer to the below image.Note: You may also refer to this article How to Import External JAR Files in Android Studio?Step 3: Adding Dependency to the build.gradle File\nGo to Module build.gradle file and add this dependency.\nimplementation 'com.pierfrancescosoffritti.androidyoutubeplayer:core:10.0.3'\nNow click on the \u201csync now\u201d option which you will get to see in the top right corner after adding this library. After that, we are ready for integrating the YouTube video player into the app.\nStep 4: Working with the activity_main.xml File\nNow change the project tab in the top left corner to Android. After that navigate to the app > res > layout > activity_main.xml. Inside this, we will create a simple button that will redirect to a new activity where we will play our YouTube video. Below is the XML code snippet for the activity_main.xml file.XML \n \n Step 5: Create a New Empty Activity\nNow we will create a new activity where we will display our YouTube video player. To create a new activity navigate to the app > java > your app\u2019s package name and right-click on it > New > Activity > Empty Activity > Give a name to your activity and select Java/Kotlin as its language. Now your new activity has been created. (Here we have given the activity name as VideoPlayerActivity).\nStep 6: Implement YoutubePlayerView inside the New Activity\nBelow is the code for the activity_video_player.xml file.XML \n \n \n \nStep 7: Working with the VideoPlayerActivity File\nBefore working with the VideoPlayerActivity file let\u2019s have a look at how to get the video id of any YouTube video.Open YouTube and search for any video which you want to play inside your app. Play that video inside your browser. In the top section of your browser, there will be an address bar where you can get to see the URL for that video. For example, here we have taken the below URL.\nhttps://www.youtube.com/watch?v=vG2PNdI8axo\nInside the above URL, the video ID is present in the extreme left part i.e after the v = sign is your video id. In the above example, the video ID will be\nvG2PNdI8axo \nIn this way, we can get the URL for any video. Now go to the VideoPlayerActivity file and refer to the following code. Below is the code for the VideoPlayerActivity file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.view.Window; \nimport android.view.WindowManager; \nimport androidx.annotation.NonNull; \nimport androidx.appcompat.app.AppCompatActivity; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.PlayerConstants; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.YouTubePlayer; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.listeners.AbstractYouTubePlayerListener; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.views.YouTubePlayerView; public class VideoPlayerActivity extends AppCompatActivity { // id of the video which we are playing. \nString video_id = \"vG2PNdI8axo\"; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); // below two lines are used to set our screen orientation in landscape mode. \nrequestWindowFeature(Window.FEATURE_NO_TITLE); \ngetWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_video_player); // below line of code is to hide our action bar. \ngetSupportActionBar().hide(); // declaring variable for youtubePlayer view \nfinal YouTubePlayerView youTubePlayerView = findViewById(R.id.videoPlayer); // below line is to place your youtube player in a full screen mode (i.e landscape mode) \nyouTubePlayerView.enterFullScreen(); \nyouTubePlayerView.toggleFullScreen(); // here we are adding observer to our youtubeplayerview. \ngetLifecycle().addObserver(youTubePlayerView); // below method will provides us the youtube player ui controller such \n// as to play and pause a video to forward a video and many more features. \nyouTubePlayerView.getPlayerUiController(); // below line is to enter full screen mode. \nyouTubePlayerView.enterFullScreen(); \nyouTubePlayerView.toggleFullScreen(); // adding listener for our youtube player view. \nyouTubePlayerView.addYouTubePlayerListener(new AbstractYouTubePlayerListener() { \n@Override\npublic void onReady(@NonNull YouTubePlayer youTubePlayer) { \n// loading the selected video into the YouTube Player \nyouTubePlayer.loadVideo(video_id, 0); \n} @Override\npublic void onStateChange(@NonNull YouTubePlayer youTubePlayer, @NonNull PlayerConstants.PlayerState state) { \n// this method is called if video has ended, \nsuper.onStateChange(youTubePlayer, state); \n} \n}); \n} \n}Kotlin import android.os.Bundle \nimport android.view.Window \nimport android.view.WindowManager \nimport androidx.appcompat.app.AppCompatActivity \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.PlayerConstants \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.YouTubePlayer \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.listeners.AbstractYouTubePlayerListener \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.views.YouTubePlayerView class VideoPlayerActivity : AppCompatActivity() { // id of the video which we are playing. \nvar video_id = \"vG2PNdI8axo\"override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) // below two lines are used to set our screen orientation in landscape mode. \nrequestWindowFeature(Window.FEATURE_NO_TITLE) \nwindow.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN) setContentView(R.layout.activity_video_player) // below line of code is to hide our action bar. \nsupportActionBar?.hide() // declaring variable for youtubePlayer view \nval youTubePlayerView: YouTubePlayerView = findViewById(R.id.videoPlayer) // below line is to place your youtube player in a full screen mode (i.e landscape mode) \nyouTubePlayerView.enterFullScreen() \nyouTubePlayerView.toggleFullScreen() // here we are adding observer to our youtubeplayerview. \nlifecycle.addObserver(youTubePlayerView) // below method will provides us the youtube player ui controller such \n// as to play and pause a video to forward a video and many more features. \nyouTubePlayerView.getPlayerUiController() // below line is to enter full screen mode. \nyouTubePlayerView.enterFullScreen() \nyouTubePlayerView.toggleFullScreen() // adding listener for our youtube player view. \nyouTubePlayerView.addYouTubePlayerListener(object : AbstractYouTubePlayerListener() { \nfun onReady(youTubePlayer: YouTubePlayer) { \n// loading the selected video into the YouTube Player \nyouTubePlayer.loadVideo(video_id, 0) \n} fun onStateChange(youTubePlayer: YouTubePlayer, state: PlayerConstants.PlayerState) { \n// this method is called if video has ended, \nsuper.onStateChange(youTubePlayer, state) \n} \n}) \n} \n}Step 8: Working with the MainActivity File\nGo to the MainActivity File and refer to the following code. Below is the code for the MainActivity File. Comments are added inside the code to understand the code in more detail.Java import android.content.Intent; \nimport android.os.Bundle; \nimport android.widget.Button; \nimport androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { // variable for our button \nButton playBtn; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // Initialize our Button \nplayBtn = findViewById(R.id.idBtnPlayVideo); // we have set onclick listener for our button \nplayBtn.setOnClickListener(v -> { \n// we have declared an intent to open new activity. \nIntent i = new Intent(MainActivity.this, VideoPlayerActivity.class); \nstartActivity(i); \n}); \n} \n}Kotlin import android.content.Intent \nimport android.os.Bundle \nimport android.widget.Button \nimport androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { // variable for our button \nlateinit var playBtn: Button override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // Initialize our Button \nplayBtn = findViewById(R.id.idBtnPlayVideo) // we have set onclick listener for our button \nplayBtn.setOnClickListener { \n// we have declared an intent to open new activity. \nval i = Intent(this, VideoPlayerActivity::class.java) \nstartActivity(i) \n} \n} \n}Step 9: Adding Permissions to the AndroidManifest.xml File\nIn AndroidManifest.xml, one needs to include the below permission, in order to access the internet. Navigate to the app > AndroidManifest.xml file there you have to add the below permissions.\n \n \n\nAlong with this, you will get to see an activity section inside your application tag. Inside that, add your video player\u2019s activity screen orientation to landscape mode.\n\n\n \nBelow is the code for the complete AndroidManifest.xml file:XML \n \n \n \n \n \n \n \n \n \n Output: Run the App on a Physical Devicehttps://media.geeksforgeeks.org/wp-content/uploads/20201214160612/Screenrecorder-2020-12-14-15-53-30-976.mp4\nCheck out the project on the below GitHub link: https://github.com/ChaitanyaMunje/YoutubePlayerView"
},
{
"instruction": "PlayerView Library in Android?If you are looking to display YouTube videos inside your app without redirecting your user from your app to YouTube then this library is very helpful for you to use. With the help of this library, you can simply play videos from YouTube with the help of a video id inside your app itself without redirecting your user to YouTube. Now we will see the implementation of this library in our Android App. We are going toimplement this project using both Java and Kotlin Programming Language for Android.\nStep by Step Implementation\nStep 1: Create a New Project in Android Studio\nTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android.\nStep 2: Add the JAR File inside the Libs Folder in Android Studio\nDownload the JAR file from this link. To add this file open your android project in \u201cProject\u201d mode as shown in the below image.Then go to Your Project Name > app > libs and right-click on it and paste the downloaded JAR files. You may also refer to the below image.Note: You may also refer to this article How to Import External JAR Files in Android Studio?Step 3: Adding Dependency to the build.gradle File\nGo to Module build.gradle file and add this dependency.\nimplementation 'com.pierfrancescosoffritti.androidyoutubeplayer:core:10.0.3'\nNow click on the \u201csync now\u201d option which you will get to see in the top right corner after adding this library. After that, we are ready for integrating the YouTube video player into the app.\nStep 4: Working with the activity_main.xml File\nNow change the project tab in the top left corner to Android. After that navigate to the app > res > layout > activity_main.xml. Inside this, we will create a simple button that will redirect to a new activity where we will play our YouTube video. Below is the XML code snippet for the activity_main.xml file.XML \n \n Step 5: Create a New Empty Activity\nNow we will create a new activity where we will display our YouTube video player. To create a new activity navigate to the app > java > your app\u2019s package name and right-click on it > New > Activity > Empty Activity > Give a name to your activity and select Java/Kotlin as its language. Now your new activity has been created. (Here we have given the activity name as VideoPlayerActivity).\nStep 6: Implement YoutubePlayerView inside the New Activity\nBelow is the code for the activity_video_player.xml file.XML \n \n \n \nStep 7: Working with the VideoPlayerActivity File\nBefore working with the VideoPlayerActivity file let\u2019s have a look at how to get the video id of any YouTube video.Open YouTube and search for any video which you want to play inside your app. Play that video inside your browser. In the top section of your browser, there will be an address bar where you can get to see the URL for that video. For example, here we have taken the below URL.\nhttps://www.youtube.com/watch?v=vG2PNdI8axo\nInside the above URL, the video ID is present in the extreme left part i.e after the v = sign is your video id. In the above example, the video ID will be\nvG2PNdI8axo \nIn this way, we can get the URL for any video. Now go to the VideoPlayerActivity file and refer to the following code. Below is the code for the VideoPlayerActivity file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.view.Window; \nimport android.view.WindowManager; \nimport androidx.annotation.NonNull; \nimport androidx.appcompat.app.AppCompatActivity; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.PlayerConstants; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.YouTubePlayer; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.listeners.AbstractYouTubePlayerListener; \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.views.YouTubePlayerView; public class VideoPlayerActivity extends AppCompatActivity { // id of the video which we are playing. \nString video_id = \"vG2PNdI8axo\"; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); // below two lines are used to set our screen orientation in landscape mode. \nrequestWindowFeature(Window.FEATURE_NO_TITLE); \ngetWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_video_player); // below line of code is to hide our action bar. \ngetSupportActionBar().hide(); // declaring variable for youtubePlayer view \nfinal YouTubePlayerView youTubePlayerView = findViewById(R.id.videoPlayer); // below line is to place your youtube player in a full screen mode (i.e landscape mode) \nyouTubePlayerView.enterFullScreen(); \nyouTubePlayerView.toggleFullScreen(); // here we are adding observer to our youtubeplayerview. \ngetLifecycle().addObserver(youTubePlayerView); // below method will provides us the youtube player ui controller such \n// as to play and pause a video to forward a video and many more features. \nyouTubePlayerView.getPlayerUiController(); // below line is to enter full screen mode. \nyouTubePlayerView.enterFullScreen(); \nyouTubePlayerView.toggleFullScreen(); // adding listener for our youtube player view. \nyouTubePlayerView.addYouTubePlayerListener(new AbstractYouTubePlayerListener() { \n@Override\npublic void onReady(@NonNull YouTubePlayer youTubePlayer) { \n// loading the selected video into the YouTube Player \nyouTubePlayer.loadVideo(video_id, 0); \n} @Override\npublic void onStateChange(@NonNull YouTubePlayer youTubePlayer, @NonNull PlayerConstants.PlayerState state) { \n// this method is called if video has ended, \nsuper.onStateChange(youTubePlayer, state); \n} \n}); \n} \n}Kotlin import android.os.Bundle \nimport android.view.Window \nimport android.view.WindowManager \nimport androidx.appcompat.app.AppCompatActivity \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.PlayerConstants \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.YouTubePlayer \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.listeners.AbstractYouTubePlayerListener \nimport com.pierfrancescosoffritti.androidyoutubeplayer.core.player.views.YouTubePlayerView class VideoPlayerActivity : AppCompatActivity() { // id of the video which we are playing. \nvar video_id = \"vG2PNdI8axo\"override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) // below two lines are used to set our screen orientation in landscape mode. \nrequestWindowFeature(Window.FEATURE_NO_TITLE) \nwindow.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN) setContentView(R.layout.activity_video_player) // below line of code is to hide our action bar. \nsupportActionBar?.hide() // declaring variable for youtubePlayer view \nval youTubePlayerView: YouTubePlayerView = findViewById(R.id.videoPlayer) // below line is to place your youtube player in a full screen mode (i.e landscape mode) \nyouTubePlayerView.enterFullScreen() \nyouTubePlayerView.toggleFullScreen() // here we are adding observer to our youtubeplayerview. \nlifecycle.addObserver(youTubePlayerView) // below method will provides us the youtube player ui controller such \n// as to play and pause a video to forward a video and many more features. \nyouTubePlayerView.getPlayerUiController() // below line is to enter full screen mode. \nyouTubePlayerView.enterFullScreen() \nyouTubePlayerView.toggleFullScreen() // adding listener for our youtube player view. \nyouTubePlayerView.addYouTubePlayerListener(object : AbstractYouTubePlayerListener() { \nfun onReady(youTubePlayer: YouTubePlayer) { \n// loading the selected video into the YouTube Player \nyouTubePlayer.loadVideo(video_id, 0) \n} fun onStateChange(youTubePlayer: YouTubePlayer, state: PlayerConstants.PlayerState) { \n// this method is called if video has ended, \nsuper.onStateChange(youTubePlayer, state) \n} \n}) \n} \n}Step 8: Working with the MainActivity File\nGo to the MainActivity File and refer to the following code. Below is the code for the MainActivity File. Comments are added inside the code to understand the code in more detail.Java import android.content.Intent; \nimport android.os.Bundle; \nimport android.widget.Button; \nimport androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { // variable for our button \nButton playBtn; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // Initialize our Button \nplayBtn = findViewById(R.id.idBtnPlayVideo); // we have set onclick listener for our button \nplayBtn.setOnClickListener(v -> { \n// we have declared an intent to open new activity. \nIntent i = new Intent(MainActivity.this, VideoPlayerActivity.class); \nstartActivity(i); \n}); \n} \n}Kotlin import android.content.Intent \nimport android.os.Bundle \nimport android.widget.Button \nimport androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { // variable for our button \nlateinit var playBtn: Button override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // Initialize our Button \nplayBtn = findViewById(R.id.idBtnPlayVideo) // we have set onclick listener for our button \nplayBtn.setOnClickListener { \n// we have declared an intent to open new activity. \nval i = Intent(this, VideoPlayerActivity::class.java) \nstartActivity(i) \n} \n} \n}Step 9: Adding Permissions to the AndroidManifest.xml File\nIn AndroidManifest.xml, one needs to include the below permission, in order to access the internet. Navigate to the app > AndroidManifest.xml file there you have to add the below permissions.\n \n \n\nAlong with this, you will get to see an activity section inside your application tag. Inside that, add your video player\u2019s activity screen orientation to landscape mode.\n\n\n \nBelow is the code for the complete AndroidManifest.xml file:XML \n \n \n \n \n \n \n \n \n \n Output: Run the App on a Physical Devicehttps://media.geeksforgeeks.org/wp-content/uploads/20201214160612/Screenrecorder-2020-12-14-15-53-30-976.mp4\nCheck out the project on the below GitHub link: https://github.com/ChaitanyaMunje/YoutubePlayerView",
"input": "",
"output": "h App using Android StudioIn this article, an Android app is created to display a basic Stopwatch.\nThe layout for Stopwatch includes:A TextView: showing how much time has passed\nThree Buttons:Start: To start the stopwatch\nStop: To stop the stopwatch\nReset: To reset the stopwatch to 00:00:00Steps to create the Stopwatch:Create a new project for Stopwatch App\nAdd String resources\nUpdate the Stopwatch layout code\nUpdate the code for activityBelow are the steps one by one in detail:Create a new project for Stopwatch AppCreate a new Android project for an application named \u201cStopwatch\u201d with a company domain of \u201cgeeksforgeeks.org\u201d, making the package name org.geeksforgeeks.stopwatch.\nCreate a New project and select Empty Activity\nConfigure the projectThe minimum SDK should be API 14 so it can run on almost all devices.\nAn empty activity called \u201cStopwatchActivity\u201d and a layout called \u201cactivity_stopwatch\u201d will be created.\nFirst opening screenAdd String resources\nWe are going to use three String values in our stopwatch layout, one for the text value of each button. These values are String resources, so they need to be added to strings.xml. Add the String values below to your version of strings.xml:Strings.xml \nGFG|Stopwatch \nStart \nStop \nReset \n Update the Stopwatch layout code\nHere is the XML for the layout. It describes a single text view that\u2019s used to display the timer, and three buttons to control the stopwatch. Replace the XML currently in activity_stopwatch.xml with the XML shown here:activity_stopwatch.xml \n\nandroid:background=\"#0F9D58\" \nandroid:padding=\"16dp\" \ntools:context=\"org.geeksforgeeks.stopwatch.StopwatchActivity\"> \n\nandroid:id=\"@+id/time_view\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \n\nandroid:textAppearance=\"@android:style/TextAppearance.Large\" \nandroid:textSize=\"56sp\" /> \n\nandroid:onClick=\"onClickStart\" \nandroid:text=\"@string/start\" /> \n\nandroid:id=\"@+id/stop_button\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \nandroid:layout_marginTop=\"8dp\" \n\nandroid:onClick=\"onClickStop\" \nandroid:text=\"@string/stop\" /> \n\nandroid:id=\"@+id/reset_button\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \nandroid:layout_marginTop=\"8dp\" \n\nandroid:onClick=\"onClickReset\" \nandroid:text=\"@string/reset\" /> \n How the activity code will work\nThe layout defines three buttons that we will use to control the stopwatch. Each button uses its onClick attribute to specify which method in the activity should run when the button is clicked. When the Start button is clicked, the onClickStart() method gets called, when the Stop button is clicked the onClickStop() method gets called, and when the Reset button is clicked the onClickReset() method gets called. We will use these methods to start, stop and reset the stopwatch.\nWe will update the stopwatch using a method we will create called runTimer(). The runTimer() method will run code every second to check whether the stopwatch is running, and, if it is, increment the number of seconds and display the number of seconds in the text view.\nTo help us with this, we will use two private variables to record the state of the stopwatch. We will use an int called seconds to track how many seconds have passed since the stopwatch started running, and a boolean called running to record whether the stopwatch is currently running.\nWe will start by writing the code for the buttons, and then we will look at the runTimer() method.Add code for the buttons When the user clicks on the Start button, we will set the running variable to true so that the stopwatch will start. When the user clicks on the Stop button, we will set running to false so that the stopwatch stops running. If the user clicks on the Reset button, we will set running to false and seconds to 0 so that the stopwatch is reset and stops running.The runTimer() method The next thing we need to do is to create the runTimer() method. This method will get a reference to the text view in the layout; format the contents of the seconds variable into hours, minutes, and seconds; and then display the results in the text view. If the running variable is set to true, it will increment the seconds variable.Handlers allow you to schedule code A Handler is an Android class you can use to schedule code that should be run at some point in the future. You can also use it to post code that needs to run on a different thread than the main Android thread. In our case, we are going to use a Handler to schedule the stopwatch code to run every second.\nTo use the Handler, you wrap the code you wish to schedule in a Runnable object, and then use the Handle post() and postDelayed() methods to specify when you want the code to run.The post() method The post() method posts code that needs to be run as soon as possible(which is usually immediately). This method takes one parameter, an object of type Runnable. A Runnable object in Androidville is just like a Runnable in plain old Java: a job you want to run. You put the code you want to run in the Runnable\u2019s run() method, and the Handler will make sure the code is run as soon as possible.The postDelayed() method The postDelayed() method works in a similar way to the post() method except that you use it to post code that should be run in the future. The postDelayed() method takes two parameters: a Runnable and a long. The Runnable contains the code you want to run in its run() method, and the long specifies the number of milliseconds you wish to delay the code by. The code will run as soon as possible after the delay.Below is the following code to StopwatchActivity.java:StopwatchActivity.java package org.geeksforgeeks.stopwatch; import android.app.Activity; \nimport android.os.Handler; \nimport android.view.View; \nimport android.os.Bundle; \nimport java.util.Locale; \nimport android.widget.TextView; public class StopwatchActivity extends Activity { // Use seconds, running and wasRunning respectively \n// to record the number of seconds passed, \n// whether the stopwatch is running and \n// whether the stopwatch was running \n// before the activity was paused. // Number of seconds displayed \n// on the stopwatch. \nprivate int seconds = 0; // Is the stopwatch running? \nprivate boolean running; private boolean wasRunning; @Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_stopwatch); \nif (savedInstanceState != null) { // Get the previous state of the stopwatch \n// if the activity has been \n// destroyed and recreated. \nseconds \n= savedInstanceState \n.getInt(\"seconds\"); \nrunning \n= savedInstanceState \n.getBoolean(\"running\"); \nwasRunning \n= savedInstanceState \n.getBoolean(\"wasRunning\"); \n} \nrunTimer(); \n} // Save the state of the stopwatch \n// if it's about to be destroyed. \n@Override\npublic void onSaveInstanceState( \nBundle savedInstanceState) \n{ \nsavedInstanceState \n.putInt(\"seconds\", seconds); \nsavedInstanceState \n.putBoolean(\"running\", running); \nsavedInstanceState \n.putBoolean(\"wasRunning\", wasRunning); \n} // If the activity is paused, \n// stop the stopwatch. \n@Override\nprotected void onPause() \n{ \nsuper.onPause(); \nwasRunning = running; \nrunning = false; \n} // If the activity is resumed, \n// start the stopwatch \n// again if it was running previously. \n@Override\nprotected void onResume() \n{ \nsuper.onResume(); \nif (wasRunning) { \nrunning = true; \n} \n} // Start the stopwatch running \n// when the Start button is clicked. \n// Below method gets called \n// when the Start button is clicked. \npublic void onClickStart(View view) \n{ \nrunning = true; \n} // Stop the stopwatch running \n// when the Stop button is clicked. \n// Below method gets called \n// when the Stop button is clicked. \npublic void onClickStop(View view) \n{ \nrunning = false; \n} // Reset the stopwatch when \n// the Reset button is clicked. \n// Below method gets called \n// when the Reset button is clicked. \npublic void onClickReset(View view) \n{ \nrunning = false; \nseconds = 0; \n} // Sets the NUmber of seconds on the timer. \n// The runTimer() method uses a Handler \n// to increment the seconds and \n// update the text view. \nprivate void runTimer() \n{ // Get the text view. \nfinal TextView timeView \n= (TextView)findViewById( \nR.id.time_view); // Creates a new Handler \nfinal Handler handler \n= new Handler(); // Call the post() method, \n// passing in a new Runnable. \n// The post() method processes \n// code without a delay, \n// so the code in the Runnable \n// will run almost immediately. \nhandler.post(new Runnable() { \n@Overridepublic void run() \n{ \nint hours = seconds / 3600; \nint minutes = (seconds % 3600) / 60; \nint secs = seconds % 60; // Format the seconds into hours, minutes, \n// and seconds. \nString time \n= String \n.format(Locale.getDefault(), \n\"%d:%02d:%02d\", hours, \nminutes, secs); // Set the text view text. \ntimeView.setText(time); // If running is true, increment the \n// seconds variable. \nif (running) { \nseconds++; \n} // Post the code again \n// with a delay of 1 second. \nhandler.postDelayed(this, 1000); \n} \n}); \n} \n} Output:\nOutput of Stopwatch App."
},
{
"instruction": "h App using Android StudioIn this article, an Android app is created to display a basic Stopwatch.\nThe layout for Stopwatch includes:A TextView: showing how much time has passed\nThree Buttons:Start: To start the stopwatch\nStop: To stop the stopwatch\nReset: To reset the stopwatch to 00:00:00Steps to create the Stopwatch:Create a new project for Stopwatch App\nAdd String resources\nUpdate the Stopwatch layout code\nUpdate the code for activityBelow are the steps one by one in detail:Create a new project for Stopwatch AppCreate a new Android project for an application named \u201cStopwatch\u201d with a company domain of \u201cgeeksforgeeks.org\u201d, making the package name org.geeksforgeeks.stopwatch.\nCreate a New project and select Empty Activity\nConfigure the projectThe minimum SDK should be API 14 so it can run on almost all devices.\nAn empty activity called \u201cStopwatchActivity\u201d and a layout called \u201cactivity_stopwatch\u201d will be created.\nFirst opening screenAdd String resources\nWe are going to use three String values in our stopwatch layout, one for the text value of each button. These values are String resources, so they need to be added to strings.xml. Add the String values below to your version of strings.xml:Strings.xml \nGFG|Stopwatch \nStart \nStop \nReset \n Update the Stopwatch layout code\nHere is the XML for the layout. It describes a single text view that\u2019s used to display the timer, and three buttons to control the stopwatch. Replace the XML currently in activity_stopwatch.xml with the XML shown here:activity_stopwatch.xml \n\nandroid:background=\"#0F9D58\" \nandroid:padding=\"16dp\" \ntools:context=\"org.geeksforgeeks.stopwatch.StopwatchActivity\"> \n\nandroid:id=\"@+id/time_view\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \n\nandroid:textAppearance=\"@android:style/TextAppearance.Large\" \nandroid:textSize=\"56sp\" /> \n\nandroid:onClick=\"onClickStart\" \nandroid:text=\"@string/start\" /> \n\nandroid:id=\"@+id/stop_button\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \nandroid:layout_marginTop=\"8dp\" \n\nandroid:onClick=\"onClickStop\" \nandroid:text=\"@string/stop\" /> \n\nandroid:id=\"@+id/reset_button\" \nandroid:layout_width=\"wrap_content\" \nandroid:layout_height=\"wrap_content\" \nandroid:layout_gravity=\"center_horizontal\" \nandroid:layout_marginTop=\"8dp\" \n\nandroid:onClick=\"onClickReset\" \nandroid:text=\"@string/reset\" /> \n How the activity code will work\nThe layout defines three buttons that we will use to control the stopwatch. Each button uses its onClick attribute to specify which method in the activity should run when the button is clicked. When the Start button is clicked, the onClickStart() method gets called, when the Stop button is clicked the onClickStop() method gets called, and when the Reset button is clicked the onClickReset() method gets called. We will use these methods to start, stop and reset the stopwatch.\nWe will update the stopwatch using a method we will create called runTimer(). The runTimer() method will run code every second to check whether the stopwatch is running, and, if it is, increment the number of seconds and display the number of seconds in the text view.\nTo help us with this, we will use two private variables to record the state of the stopwatch. We will use an int called seconds to track how many seconds have passed since the stopwatch started running, and a boolean called running to record whether the stopwatch is currently running.\nWe will start by writing the code for the buttons, and then we will look at the runTimer() method.Add code for the buttons When the user clicks on the Start button, we will set the running variable to true so that the stopwatch will start. When the user clicks on the Stop button, we will set running to false so that the stopwatch stops running. If the user clicks on the Reset button, we will set running to false and seconds to 0 so that the stopwatch is reset and stops running.The runTimer() method The next thing we need to do is to create the runTimer() method. This method will get a reference to the text view in the layout; format the contents of the seconds variable into hours, minutes, and seconds; and then display the results in the text view. If the running variable is set to true, it will increment the seconds variable.Handlers allow you to schedule code A Handler is an Android class you can use to schedule code that should be run at some point in the future. You can also use it to post code that needs to run on a different thread than the main Android thread. In our case, we are going to use a Handler to schedule the stopwatch code to run every second.\nTo use the Handler, you wrap the code you wish to schedule in a Runnable object, and then use the Handle post() and postDelayed() methods to specify when you want the code to run.The post() method The post() method posts code that needs to be run as soon as possible(which is usually immediately). This method takes one parameter, an object of type Runnable. A Runnable object in Androidville is just like a Runnable in plain old Java: a job you want to run. You put the code you want to run in the Runnable\u2019s run() method, and the Handler will make sure the code is run as soon as possible.The postDelayed() method The postDelayed() method works in a similar way to the post() method except that you use it to post code that should be run in the future. The postDelayed() method takes two parameters: a Runnable and a long. The Runnable contains the code you want to run in its run() method, and the long specifies the number of milliseconds you wish to delay the code by. The code will run as soon as possible after the delay.Below is the following code to StopwatchActivity.java:StopwatchActivity.java package org.geeksforgeeks.stopwatch; import android.app.Activity; \nimport android.os.Handler; \nimport android.view.View; \nimport android.os.Bundle; \nimport java.util.Locale; \nimport android.widget.TextView; public class StopwatchActivity extends Activity { // Use seconds, running and wasRunning respectively \n// to record the number of seconds passed, \n// whether the stopwatch is running and \n// whether the stopwatch was running \n// before the activity was paused. // Number of seconds displayed \n// on the stopwatch. \nprivate int seconds = 0; // Is the stopwatch running? \nprivate boolean running; private boolean wasRunning; @Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_stopwatch); \nif (savedInstanceState != null) { // Get the previous state of the stopwatch \n// if the activity has been \n// destroyed and recreated. \nseconds \n= savedInstanceState \n.getInt(\"seconds\"); \nrunning \n= savedInstanceState \n.getBoolean(\"running\"); \nwasRunning \n= savedInstanceState \n.getBoolean(\"wasRunning\"); \n} \nrunTimer(); \n} // Save the state of the stopwatch \n// if it's about to be destroyed. \n@Override\npublic void onSaveInstanceState( \nBundle savedInstanceState) \n{ \nsavedInstanceState \n.putInt(\"seconds\", seconds); \nsavedInstanceState \n.putBoolean(\"running\", running); \nsavedInstanceState \n.putBoolean(\"wasRunning\", wasRunning); \n} // If the activity is paused, \n// stop the stopwatch. \n@Override\nprotected void onPause() \n{ \nsuper.onPause(); \nwasRunning = running; \nrunning = false; \n} // If the activity is resumed, \n// start the stopwatch \n// again if it was running previously. \n@Override\nprotected void onResume() \n{ \nsuper.onResume(); \nif (wasRunning) { \nrunning = true; \n} \n} // Start the stopwatch running \n// when the Start button is clicked. \n// Below method gets called \n// when the Start button is clicked. \npublic void onClickStart(View view) \n{ \nrunning = true; \n} // Stop the stopwatch running \n// when the Stop button is clicked. \n// Below method gets called \n// when the Stop button is clicked. \npublic void onClickStop(View view) \n{ \nrunning = false; \n} // Reset the stopwatch when \n// the Reset button is clicked. \n// Below method gets called \n// when the Reset button is clicked. \npublic void onClickReset(View view) \n{ \nrunning = false; \nseconds = 0; \n} // Sets the NUmber of seconds on the timer. \n// The runTimer() method uses a Handler \n// to increment the seconds and \n// update the text view. \nprivate void runTimer() \n{ // Get the text view. \nfinal TextView timeView \n= (TextView)findViewById( \nR.id.time_view); // Creates a new Handler \nfinal Handler handler \n= new Handler(); // Call the post() method, \n// passing in a new Runnable. \n// The post() method processes \n// code without a delay, \n// so the code in the Runnable \n// will run almost immediately. \nhandler.post(new Runnable() { \n@Overridepublic void run() \n{ \nint hours = seconds / 3600; \nint minutes = (seconds % 3600) / 60; \nint secs = seconds % 60; // Format the seconds into hours, minutes, \n// and seconds. \nString time \n= String \n.format(Locale.getDefault(), \n\"%d:%02d:%02d\", hours, \nminutes, secs); // Set the text view text. \ntimeView.setText(time); // If running is true, increment the \n// seconds variable. \nif (running) { \nseconds++; \n} // Post the code again \n// with a delay of 1 second. \nhandler.postDelayed(this, 1000); \n} \n}); \n} \n} Output:\nOutput of Stopwatch App.",
"input": "",
"output": "Fundamentals for BeginnersAndroid is an operating system that is built basically for Mobile phones. It is based on the Linux Kernel and other open-source software and is developed by Google. It is used for touchscreen mobile devices such as smartphones and tablets. But nowadays these are used in Android Auto cars, TV, watches, camera, etc. It has been one of the best-selling OS for smartphones. Android OS was developed by Android Inc. which Google bought in 2005. Various applications (apps) like games, music player, camera, etc. are built for these smartphones for running on Android. Google Play store features more than 3.3 million apps. The app is developed on an application known as Android Studio. These executable apps are installed through a bundle or package called APK(Android Package Kit).\nAndroid Fundamentals\n1. Android Programming Languages\nIn Android, basically, programming is done in two languages JAVA or C++ and XML(Extension Markup Language). Nowadays KOTLIN is also preferred. The XML file deals with the design, presentation, layouts, blueprint, etc (as a front-end) while the JAVA or KOTLIN deals with the working of buttons, variables, storing, etc (as a back-end).\n2. Android Components\nThe App components are the building blocks of Android. Each component has its own role and life cycles i.e from launching of an app till the end. Some of these components depend upon others also. Each component has a definite purpose. The four major app components are:Activities\nServices\nBroadcast Receivers:\nContent Provider:Activities: It deals with the UI and the user interactions to the screen. In other words, it is a User Interface that contains activities. These can be one or more depending upon the App. It starts when the application is launched. At least one activity is always present which is known as MainActivity. The activity is implemented through the following. \nSyntax:\npublic class MainActivity extends Activity{\n // processes\n}\nTo know more Activities please refer to this article: Introduction to Activities in Android\nServices: Services are the background actions performed by the app, these might be long-running operations like a user playing music while surfing the Internet. A service might need other sub-services so as to perform specific tasks. The main purpose of the Services is to provide non-stop working of the app without breaking any interaction with the user.\nSyntax:\npublic class MyServices extends Services{\n // code for the services\n}\nTo know more Services please refer to this article:Services in Android with Example\nBroadcast Receivers: A Broadcast is used to respond to messages from other applications or from the System. For example, when the battery of the phone is low, then the Android OS fires a Broadcasting message to launch the Battery Saver function or app, after receiving the message the appropriate action is taken by the app. Broadcast Receiver is the subclass of BroadcastReceiver class and each object is represented by Intent objects.\nSyntax: \npublic class MyReceiver extends BroadcastReceiver{\n public void onReceive(context,intent){\n }\nTo know more Broadcast Receivers please refer to this article:Broadcast Receiver in Android With Example\nContent Provider: Content Provider is used to transferring the data from one application to the others at the request of the other application. These are handled by the class ContentResolver class. This class implements a set of APIs(Application Programming Interface) that enables the other applications to perform the transactions. Any Content Provider must implement the Parent Class of ContentProvider class.\nSyntax:\npublic class MyContentProvider extends ContentProvider{\n public void onCreate()\n {}\n}\nTo know more Content Provider please refer to this article:Content Providers in Android with Example\n3. Structural Layout Of Android Studio\nThe basic structural layout of Android Studio is given below:The above figure represents the various structure of an app.\nManifest Folder: Android Manifest is an XML file that is the root of the project source set. It describes the essential information about the app and the Android build tools, the Android Operating System, and Google Play. It contains the permission that an app might need in order to perform a specific task. It also contains the Hardware and the Software features of the app, which determines the compatibility of an app on the Play Store. It also includes special activities like services, broadcast receiver, content providers, package name, etc.\nJava Folder: The JAVA folder consists of the java files that are required to perform the background task of the app. It consists of the functionality of the buttons, calculation, storing, variables, toast(small popup message), programming function, etc. The number of these files depends upon the type of activities created.\nResource Folder: The res or Resource folder consists of the various resources that are used in the app. This consists of sub-folders like drawable, layout, mipmap, raw, and values. The drawable consists of the images. The layout consists of the XML files that define the user interface layout. These are stored in res.layout and are accessed as R.layout class. The raw consists of the Resources files like audio files or music files, etc. These are accessed through R.raw.filename. values are used to store the hardcoded strings(considered safe to store string values) values, integers, and colors. It consists of various other directories like:R.array :arrays.xml for resource arrays\nR.integer : integers.xml for resource integers\nR.bool : bools.xml for resource boolean\nR.color :colors.xml for color values\nR.string : strings.xml for string values\nR.dimen : dimens.xml for dimension values\nR.style : styles.xml for stylesGradle Files: Gradle is an advanced toolkit, which is used to manage the build process, that allows defining the flexible custom build configurations. Each build configuration can define its own set of code and resources while reusing the parts common to all versions of your app. The Android plugin for Gradle works with the build toolkit to provide processes and configurable settings that are specific to building and testing Android applications. Gradle and the Android plugin run independently of Android Studio. This means that you can build your Android apps from within Android Studio. The flexibility of the Android build system enables you to perform custom build configurations without modifying your app\u2019s core source files.\nBasic Layout Can be defined in a tree structure as:\nProject/\n app/\n manifest/\n AndroidManifest.xml\n java/\n MyActivity.java \n res/\n drawable/ \n icon.png\n background.png\n drawable-hdpi/ \n icon.png\n background.png \n layout/ \n activity_main.xml\n info.xml\n values/ \n strings.xml \n4. Lifecycle of Activity in Android App\nThe Lifecycle of Activity in Android App can be shown through this diagram:States of Android Lifecycle:OnCreate: This is called when activity is first created.\nOnStart: This is called when the activity becomes visible to the user.\nOnResume: This is called when the activity starts to interact with the user.\nOnPause: This is called when activity is not visible to the user.\nOnStop: This is called when activity is no longer visible.\nOnRestart: This is called when activity is stopped, and restarted again.\nOnDestroy: This is called when activity is to be closed or destroyed.To know more about Activity Lifecycle in Android Please refer to this article: Activity Lifecycle in Android with Demo App\nTo begin your journey in Android you may refer to these tutorials:Android Tutorial\nKotlin Android Tutorial\nAndroid Studio Tutorial\nAndroid Projects \u2013 From Basic to Advanced Level"
},
{
"instruction": "Fundamentals for BeginnersAndroid is an operating system that is built basically for Mobile phones. It is based on the Linux Kernel and other open-source software and is developed by Google. It is used for touchscreen mobile devices such as smartphones and tablets. But nowadays these are used in Android Auto cars, TV, watches, camera, etc. It has been one of the best-selling OS for smartphones. Android OS was developed by Android Inc. which Google bought in 2005. Various applications (apps) like games, music player, camera, etc. are built for these smartphones for running on Android. Google Play store features more than 3.3 million apps. The app is developed on an application known as Android Studio. These executable apps are installed through a bundle or package called APK(Android Package Kit).\nAndroid Fundamentals\n1. Android Programming Languages\nIn Android, basically, programming is done in two languages JAVA or C++ and XML(Extension Markup Language). Nowadays KOTLIN is also preferred. The XML file deals with the design, presentation, layouts, blueprint, etc (as a front-end) while the JAVA or KOTLIN deals with the working of buttons, variables, storing, etc (as a back-end).\n2. Android Components\nThe App components are the building blocks of Android. Each component has its own role and life cycles i.e from launching of an app till the end. Some of these components depend upon others also. Each component has a definite purpose. The four major app components are:Activities\nServices\nBroadcast Receivers:\nContent Provider:Activities: It deals with the UI and the user interactions to the screen. In other words, it is a User Interface that contains activities. These can be one or more depending upon the App. It starts when the application is launched. At least one activity is always present which is known as MainActivity. The activity is implemented through the following. \nSyntax:\npublic class MainActivity extends Activity{\n // processes\n}\nTo know more Activities please refer to this article: Introduction to Activities in Android\nServices: Services are the background actions performed by the app, these might be long-running operations like a user playing music while surfing the Internet. A service might need other sub-services so as to perform specific tasks. The main purpose of the Services is to provide non-stop working of the app without breaking any interaction with the user.\nSyntax:\npublic class MyServices extends Services{\n // code for the services\n}\nTo know more Services please refer to this article:Services in Android with Example\nBroadcast Receivers: A Broadcast is used to respond to messages from other applications or from the System. For example, when the battery of the phone is low, then the Android OS fires a Broadcasting message to launch the Battery Saver function or app, after receiving the message the appropriate action is taken by the app. Broadcast Receiver is the subclass of BroadcastReceiver class and each object is represented by Intent objects.\nSyntax: \npublic class MyReceiver extends BroadcastReceiver{\n public void onReceive(context,intent){\n }\nTo know more Broadcast Receivers please refer to this article:Broadcast Receiver in Android With Example\nContent Provider: Content Provider is used to transferring the data from one application to the others at the request of the other application. These are handled by the class ContentResolver class. This class implements a set of APIs(Application Programming Interface) that enables the other applications to perform the transactions. Any Content Provider must implement the Parent Class of ContentProvider class.\nSyntax:\npublic class MyContentProvider extends ContentProvider{\n public void onCreate()\n {}\n}\nTo know more Content Provider please refer to this article:Content Providers in Android with Example\n3. Structural Layout Of Android Studio\nThe basic structural layout of Android Studio is given below:The above figure represents the various structure of an app.\nManifest Folder: Android Manifest is an XML file that is the root of the project source set. It describes the essential information about the app and the Android build tools, the Android Operating System, and Google Play. It contains the permission that an app might need in order to perform a specific task. It also contains the Hardware and the Software features of the app, which determines the compatibility of an app on the Play Store. It also includes special activities like services, broadcast receiver, content providers, package name, etc.\nJava Folder: The JAVA folder consists of the java files that are required to perform the background task of the app. It consists of the functionality of the buttons, calculation, storing, variables, toast(small popup message), programming function, etc. The number of these files depends upon the type of activities created.\nResource Folder: The res or Resource folder consists of the various resources that are used in the app. This consists of sub-folders like drawable, layout, mipmap, raw, and values. The drawable consists of the images. The layout consists of the XML files that define the user interface layout. These are stored in res.layout and are accessed as R.layout class. The raw consists of the Resources files like audio files or music files, etc. These are accessed through R.raw.filename. values are used to store the hardcoded strings(considered safe to store string values) values, integers, and colors. It consists of various other directories like:R.array :arrays.xml for resource arrays\nR.integer : integers.xml for resource integers\nR.bool : bools.xml for resource boolean\nR.color :colors.xml for color values\nR.string : strings.xml for string values\nR.dimen : dimens.xml for dimension values\nR.style : styles.xml for stylesGradle Files: Gradle is an advanced toolkit, which is used to manage the build process, that allows defining the flexible custom build configurations. Each build configuration can define its own set of code and resources while reusing the parts common to all versions of your app. The Android plugin for Gradle works with the build toolkit to provide processes and configurable settings that are specific to building and testing Android applications. Gradle and the Android plugin run independently of Android Studio. This means that you can build your Android apps from within Android Studio. The flexibility of the Android build system enables you to perform custom build configurations without modifying your app\u2019s core source files.\nBasic Layout Can be defined in a tree structure as:\nProject/\n app/\n manifest/\n AndroidManifest.xml\n java/\n MyActivity.java \n res/\n drawable/ \n icon.png\n background.png\n drawable-hdpi/ \n icon.png\n background.png \n layout/ \n activity_main.xml\n info.xml\n values/ \n strings.xml \n4. Lifecycle of Activity in Android App\nThe Lifecycle of Activity in Android App can be shown through this diagram:States of Android Lifecycle:OnCreate: This is called when activity is first created.\nOnStart: This is called when the activity becomes visible to the user.\nOnResume: This is called when the activity starts to interact with the user.\nOnPause: This is called when activity is not visible to the user.\nOnStop: This is called when activity is no longer visible.\nOnRestart: This is called when activity is stopped, and restarted again.\nOnDestroy: This is called when activity is to be closed or destroyed.To know more about Activity Lifecycle in Android Please refer to this article: Activity Lifecycle in Android with Demo App\nTo begin your journey in Android you may refer to these tutorials:Android Tutorial\nKotlin Android Tutorial\nAndroid Studio Tutorial\nAndroid Projects \u2013 From Basic to Advanced Level",
"input": "",
"output": "Android Switch is also a two-state user interface element that is used to toggle between ON and OFF as a button. By touching the button we can drag it back and forth to make it either ON or OFF.The Switch element is useful when only two states require for activity either choose ON or OFF. We can add a Switch to our application layout by using the Switch object. By default, the state for the android Switch is OFF state. We can also change the state of Switch to ON by setting the android:checked = \u201ctrue\u201d in our XML layout file.In android, we can create Switch control in two ways either by using Switch in XML layout file or creating it in Kotlin file dynamically.First, we create a new project by following the below steps:Click on File, then New => New Project.\nAfter that include the Kotlin support and click on next.\nSelect the minimum SDK as per convenience and click next button.\nThen select the Empty activity => next => finish.LinearLayout in activity_main.xml file\nIn this file, we use the LinearLayout and can not add the switch widget manually because it will be created dynamically in Kotlin file.XML \nAdd application name in strings.xml fileHere, we can put all the strings which can be used in the application in any file. So, we update the app_name which can be seen at the top of the activity.XML \nDynamicSwitchInKotlin \n Creating switches programmatically in MainActivity.kt file\nHere, we initialize and define two switches and add dynamically by calling on the linearLayout.\nlinearLayout?.addView(switch1)\nlinearLayout?.addView(switch2)\nthen, set OnClickListener on both the switches for functioning like toggle of button and Toast message like this.\nswitch1.setOnCheckedChangeListener { buttonView, isChecked ->\n val msg = if (isChecked) \"SW1:ON\" else \"SW1:OFF\"\n Toast.makeText(this@MainActivity, msg,\n Toast.LENGTH_SHORT).show()\n }\nComplete code for the Kotlin file is below.Kotlin package com.geeksforgeeks.myfirstkotlinapp\nimport androidx.appcompat.app.AppCompatActivity\nimport android.os.Bundle\nimport android.view.ViewGroup\nimport android.widget.LinearLayout\nimport android.widget.Switch\nimport android.widget.Toastclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)// Creating switch1 and switch2 programmatically\nval switch1 = Switch(this)\nval layoutParams = LinearLayout.LayoutParams(ViewGroup.\nLayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)\nswitch1.layoutParams = layoutParams\nswitch1.text = \"Switch1\"val switch2 = Switch(this)\nval layoutParams2 = LinearLayout.LayoutParams(ViewGroup.\nLayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)\nswitch2.layoutParams = layoutParams2\nswitch2.text = \"Switch2\"val linearLayout = findViewById(R.id.rootContainer)\n// Adding Switches to LinearLayout\nlinearLayout?.addView(switch1)\nlinearLayout?.addView(switch2)switch1.setOnCheckedChangeListener { buttonView, isChecked ->\nval msg = if (isChecked) \"SW1:ON\" else \"SW1:OFF\"\nToast.makeText(this@MainActivity, msg,\nToast.LENGTH_SHORT).show()\n}switch2.setOnCheckedChangeListener { buttonView, isChecked ->\nval msg = if (isChecked) \"SW2:ON\" else \"SW2:OFF\"\nToast.makeText(this@MainActivity, msg,\nToast.LENGTH_SHORT).show()\n}\n}\n}AndroidManifest.xml fileXML \n\n\n\n \n \n Add application name in strings.xml fileHere, we can put all the strings which can be used in the application in any file. So, we update the app_name which can be seen at the top of the activity.XML \nDynamicSwitchInKotlin \n Creating switches programmatically in MainActivity.kt file\nHere, we initialize and define two switches and add dynamically by calling on the linearLayout.\nlinearLayout?.addView(switch1)\nlinearLayout?.addView(switch2)\nthen, set OnClickListener on both the switches for functioning like toggle of button and Toast message like this.\nswitch1.setOnCheckedChangeListener { buttonView, isChecked ->\n val msg = if (isChecked) \"SW1:ON\" else \"SW1:OFF\"\n Toast.makeText(this@MainActivity, msg,\n Toast.LENGTH_SHORT).show()\n }\nComplete code for the Kotlin file is below.Kotlin package com.geeksforgeeks.myfirstkotlinapp\nimport androidx.appcompat.app.AppCompatActivity\nimport android.os.Bundle\nimport android.view.ViewGroup\nimport android.widget.LinearLayout\nimport android.widget.Switch\nimport android.widget.Toastclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)// Creating switch1 and switch2 programmatically\nval switch1 = Switch(this)\nval layoutParams = LinearLayout.LayoutParams(ViewGroup.\nLayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)\nswitch1.layoutParams = layoutParams\nswitch1.text = \"Switch1\"val switch2 = Switch(this)\nval layoutParams2 = LinearLayout.LayoutParams(ViewGroup.\nLayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)\nswitch2.layoutParams = layoutParams2\nswitch2.text = \"Switch2\"val linearLayout = findViewById(R.id.rootContainer)\n// Adding Switches to LinearLayout\nlinearLayout?.addView(switch1)\nlinearLayout?.addView(switch2)switch1.setOnCheckedChangeListener { buttonView, isChecked ->\nval msg = if (isChecked) \"SW1:ON\" else \"SW1:OFF\"\nToast.makeText(this@MainActivity, msg,\nToast.LENGTH_SHORT).show()\n}switch2.setOnCheckedChangeListener { buttonView, isChecked ->\nval msg = if (isChecked) \"SW2:ON\" else \"SW2:OFF\"\nToast.makeText(this@MainActivity, msg,\nToast.LENGTH_SHORT).show()\n}\n}\n}AndroidManifest.xml fileXML \n\n\n\n \n \n Step 4: Working with the MainActivity.java file\nNow go to the java folder and in MainActivity.java and provide the implementation to the ArrayAdapter. Below is the code for theMainActivity.java file.Java import android.os.Bundle; \nimport android.widget.ArrayAdapter; \nimport android.widget.ListView; \nimport androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { ListView simpleListView; // array objects \nString courseList[] = {\"C-Programming\", \"Data Structure\", \"Database\", \"Python\", \n\"Java\", \"Operating System\", \"Compiler Design\", \"Android Development\"}; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); simpleListView = (ListView) findViewById(R.id.simpleListView); ArrayAdapter arrayAdapter = new ArrayAdapter(this, \nR.layout.item_view, R.id.itemTextView, courseList); \nsimpleListView.setAdapter(arrayAdapter); \n} \n}Output: Run on Emulator"
},
{
"instruction": "with ExampleThe Adapter acts as a bridge between the UI Component and the Data Source. It converts data from the data sources into view items that can be displayed into the UI Component. Data Source can be Arrays, HashMap, Database, etc. and UI Components can be ListView, GridView, Spinner, etc. ArrayAdapter is the most commonly used adapter in android. When you have a list of single type items which are stored in an array you can use ArrayAdapter. Likewise, if you have a list of phone numbers, names, or cities. ArrayAdapter has a layout with a single TextView. If you want to have a more complex layout instead of ArrayAdapter use CustomArrayAdapter. The basic syntax for ArrayAdapter is given as:public ArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects)ParametersParametersDescriptioncontext\nThe current context. This value can not be null.resource\nThe resource ID for the layout file containing a layout to use when instantiating views.textViewResourceId\nThe id of the TextView within the layout resource to be populated.objects\nThe objects to represent in the ListView. This value cannot be null.context: It is used to pass the reference of the current class. Here \u2018this\u2019 keyword is used to pass the current class reference. Instead of \u2018this\u2019 we could also use the getApplicationContext() method which is used for the Activity and the getApplication() method which is used for Fragments.public ArrayAdapter(this, int resource, int textViewResourceId, T[] objects)resource: It is used to set the layout file(.xml files) for the list items.public ArrayAdapter(this, R.layout.itemListView, int textViewResourceId, T[] objects)textViewResourceId: It is used to set the TextView where you want to display the text data.public ArrayAdapter(this, R.layout.itemListView, R.id.itemTextView, T[] objects)objects: These are the array object which is used to set the array element into the TextView.String courseList[] = {\u201cC-Programming\u201d, \u201cData Structure\u201d, \u201cDatabase\u201d, \u201cPython\u201d,\n \u201cJava\u201d, \u201cOperating System\u201d,\u201dCompiler Design\u201d, \u201cAndroid Development\u201d};\nArrayAdapter arrayAdapter = new ArrayAdapter(this, R.layout.itemListView, R.id.itemTextView, courseList[]);Example\nIn this example, the list of courses is displayed using a simple array adapter. Note that we are going toimplement this project using theJavalanguage.\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Working with the activity_main.xml file\nGo to the layout folder and in activity_main.xml file change the ConstraintLayout to RelativeLayout and insert a ListView with id simpleListView. Below is the code for theactivity_main.xml file.XML \n arrayAdapter = new ArrayAdapter(this, \nR.layout.item_view, R.id.itemTextView, courseList); \nsimpleListView.setAdapter(arrayAdapter); \n} \n}Output: Run on Emulator",
"input": "",
"output": "roidThe navigation drawer is the most common feature offered by android and the navigation drawer is a UI panel that shows your app\u2019s main navigation menu. It is also one of the important UI elements, which provides actions preferable to the users, for example changing user profile, changing settings of the application, etc. In this article, it has been discussed step by step to implement the navigation drawer in android. The code has been given in both Java and Kotlin Programming Language for Android.The navigation drawer slides in from the left and contains the navigation destinations for the app.The user can view the navigation drawer when the user swipes a finger from the left edge of the activity. They can also find it from the home activity by tapping the app icon in the action bar. The drawer icon is displayed on all top-level destinations that use a DrawerLayout. Have a look at the following image to get an idea about the Navigation drawer.Steps to Implement Navigation Drawer in Android\nStep 1: Create a New Android Studio Project\nCreate an empty activity android studio project. Refer to Android | How to Create/Start a New Project in Android Studio? on how to create an empty activity android studio project.\nStep 2: Adding a dependency to the project\nIn this discussion, we are going to use the Material Design Navigation drawer. So add the following Material design dependency to the app-level Gradle file.\nimplementation 'com.google.android.material:material:1.3.0-alpha03'\nRefer to the following image if unable to locate the app-level Gradle file that invokes the dependency (under project hierarchy view). After invoking the dependency click on the \u201cSync Now\u201d button. Make sure the system is connected to the network so that Android Studio downloads the required files.Step 3: Creating a menu in the menu folder\nCreate the menu folder under the res folder. To implement the menu. Refer to the following video to create the layout to implement the menu.https://media.geeksforgeeks.org/wp-content/uploads/20201114124319/Untitled-Project.mp4\nInvoke the following code in the navigation_menu.xmlXML \n Step 4: Working with the activity_main.xml File\nInvoke the following code in the activity_main.xml to set up the basic things required for the Navigation Drawer.XML \nNavigation Drawer \n\nOpen \nClose \n Step 6: Working with the MainActivity FileInvoke the following code in the MainActivity file to show the menu icon on the action bar and implement the open-close functionality of the navigation drawer.\nComments are added inside the code for better understanding.Java import androidx.annotation.NonNull; \nimport androidx.appcompat.app.ActionBarDrawerToggle; \nimport androidx.appcompat.app.AppCompatActivity; \nimport androidx.drawerlayout.widget.DrawerLayout; \nimport android.os.Bundle; \nimport android.view.MenuItem; public class MainActivity extends AppCompatActivity { public DrawerLayout drawerLayout; \npublic ActionBarDrawerToggle actionBarDrawerToggle; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // drawer layout instance to toggle the menu icon to open \n// drawer and back button to close drawer \ndrawerLayout = findViewById(R.id.my_drawer_layout); \nactionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.nav_open, R.string.nav_close); // pass the Open and Close toggle for the drawer layout listener \n// to toggle the button \ndrawerLayout.addDrawerListener(actionBarDrawerToggle); \nactionBarDrawerToggle.syncState(); // to make the Navigation drawer icon always appear on the action bar \ngetSupportActionBar().setDisplayHomeAsUpEnabled(true); \n} // override the onOptionsItemSelected() \n// function to implement \n// the item click listener callback \n// to open and close the navigation \n// drawer when the icon is clicked \n@Override\npublic boolean onOptionsItemSelected(@NonNull MenuItem item) { if (actionBarDrawerToggle.onOptionsItemSelected(item)) { \nreturn true; \n} \nreturn super.onOptionsItemSelected(item); \n} \n}Kotlin import android.os.Bundle \nimport android.view.MenuItem \nimport androidx.appcompat.app.ActionBarDrawerToggle \nimport androidx.appcompat.app.AppCompatActivity \nimport androidx.drawerlayout.widget.DrawerLayout class MainActivity : AppCompatActivity() { \nlateinit var drawerLayout: DrawerLayout \nlateinit var actionBarDrawerToggle: ActionBarDrawerToggle override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // drawer layout instance to toggle the menu icon to open \n// drawer and back button to close drawer \ndrawerLayout = findViewById(R.id.my_drawer_layout) \nactionBarDrawerToggle = ActionBarDrawerToggle(this, drawerLayout, R.string.nav_open, R.string.nav_close) // pass the Open and Close toggle for the drawer layout listener \n// to toggle the button \ndrawerLayout.addDrawerListener(actionBarDrawerToggle) \nactionBarDrawerToggle.syncState() // to make the Navigation drawer icon always appear on the action bar \nsupportActionBar?.setDisplayHomeAsUpEnabled(true) \n} // override the onOptionsItemSelected() \n// function to implement \n// the item click listener callback \n// to open and close the navigation \n// drawer when the icon is clicked \noverride fun onOptionsItemSelected(item: MenuItem): Boolean { \nreturn if (actionBarDrawerToggle.onOptionsItemSelected(item)) { \ntrue\n} else super.onOptionsItemSelected(item) \n} \n}Output: Run on Emulator\nhttps://media.geeksforgeeks.org/wp-content/uploads/20201114130020/Untitled-Project.mp4"
},
{
"instruction": "roidThe navigation drawer is the most common feature offered by android and the navigation drawer is a UI panel that shows your app\u2019s main navigation menu. It is also one of the important UI elements, which provides actions preferable to the users, for example changing user profile, changing settings of the application, etc. In this article, it has been discussed step by step to implement the navigation drawer in android. The code has been given in both Java and Kotlin Programming Language for Android.The navigation drawer slides in from the left and contains the navigation destinations for the app.The user can view the navigation drawer when the user swipes a finger from the left edge of the activity. They can also find it from the home activity by tapping the app icon in the action bar. The drawer icon is displayed on all top-level destinations that use a DrawerLayout. Have a look at the following image to get an idea about the Navigation drawer.Steps to Implement Navigation Drawer in Android\nStep 1: Create a New Android Studio Project\nCreate an empty activity android studio project. Refer to Android | How to Create/Start a New Project in Android Studio? on how to create an empty activity android studio project.\nStep 2: Adding a dependency to the project\nIn this discussion, we are going to use the Material Design Navigation drawer. So add the following Material design dependency to the app-level Gradle file.\nimplementation 'com.google.android.material:material:1.3.0-alpha03'\nRefer to the following image if unable to locate the app-level Gradle file that invokes the dependency (under project hierarchy view). After invoking the dependency click on the \u201cSync Now\u201d button. Make sure the system is connected to the network so that Android Studio downloads the required files.Step 3: Creating a menu in the menu folder\nCreate the menu folder under the res folder. To implement the menu. Refer to the following video to create the layout to implement the menu.https://media.geeksforgeeks.org/wp-content/uploads/20201114124319/Untitled-Project.mp4\nInvoke the following code in the navigation_menu.xmlXML \n Step 4: Working with the activity_main.xml File\nInvoke the following code in the activity_main.xml to set up the basic things required for the Navigation Drawer.XML \nNavigation Drawer \n\nOpen \nClose \n Step 6: Working with the MainActivity FileInvoke the following code in the MainActivity file to show the menu icon on the action bar and implement the open-close functionality of the navigation drawer.\nComments are added inside the code for better understanding.Java import androidx.annotation.NonNull; \nimport androidx.appcompat.app.ActionBarDrawerToggle; \nimport androidx.appcompat.app.AppCompatActivity; \nimport androidx.drawerlayout.widget.DrawerLayout; \nimport android.os.Bundle; \nimport android.view.MenuItem; public class MainActivity extends AppCompatActivity { public DrawerLayout drawerLayout; \npublic ActionBarDrawerToggle actionBarDrawerToggle; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // drawer layout instance to toggle the menu icon to open \n// drawer and back button to close drawer \ndrawerLayout = findViewById(R.id.my_drawer_layout); \nactionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.nav_open, R.string.nav_close); // pass the Open and Close toggle for the drawer layout listener \n// to toggle the button \ndrawerLayout.addDrawerListener(actionBarDrawerToggle); \nactionBarDrawerToggle.syncState(); // to make the Navigation drawer icon always appear on the action bar \ngetSupportActionBar().setDisplayHomeAsUpEnabled(true); \n} // override the onOptionsItemSelected() \n// function to implement \n// the item click listener callback \n// to open and close the navigation \n// drawer when the icon is clicked \n@Override\npublic boolean onOptionsItemSelected(@NonNull MenuItem item) { if (actionBarDrawerToggle.onOptionsItemSelected(item)) { \nreturn true; \n} \nreturn super.onOptionsItemSelected(item); \n} \n}Kotlin import android.os.Bundle \nimport android.view.MenuItem \nimport androidx.appcompat.app.ActionBarDrawerToggle \nimport androidx.appcompat.app.AppCompatActivity \nimport androidx.drawerlayout.widget.DrawerLayout class MainActivity : AppCompatActivity() { \nlateinit var drawerLayout: DrawerLayout \nlateinit var actionBarDrawerToggle: ActionBarDrawerToggle override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // drawer layout instance to toggle the menu icon to open \n// drawer and back button to close drawer \ndrawerLayout = findViewById(R.id.my_drawer_layout) \nactionBarDrawerToggle = ActionBarDrawerToggle(this, drawerLayout, R.string.nav_open, R.string.nav_close) // pass the Open and Close toggle for the drawer layout listener \n// to toggle the button \ndrawerLayout.addDrawerListener(actionBarDrawerToggle) \nactionBarDrawerToggle.syncState() // to make the Navigation drawer icon always appear on the action bar \nsupportActionBar?.setDisplayHomeAsUpEnabled(true) \n} // override the onOptionsItemSelected() \n// function to implement \n// the item click listener callback \n// to open and close the navigation \n// drawer when the icon is clicked \noverride fun onOptionsItemSelected(item: MenuItem): Boolean { \nreturn if (actionBarDrawerToggle.onOptionsItemSelected(item)) { \ntrue\n} else super.onOptionsItemSelected(item) \n} \n}Output: Run on Emulator\nhttps://media.geeksforgeeks.org/wp-content/uploads/20201114130020/Untitled-Project.mp4",
"input": "",
"output": "itText in Android?EditText is an android widget. It is a User Interface element used for entering and modifying data. It returns data in String format. Masking refers to the process of putting something in place of something else. Therefore by Masking an EditText, the blank space is replaced with some default text, known as Mask. This mask gets removed as soon as the user enters any character as input, and reappears when the text has been removed from the EditText. In this article, the masking is done with the help of JitPack Library, because it can be customized easily according to the need to implement various fields like phone number, date, etc. The code has been given in both Java and Kotlin Programming Language for Android.Approach:\nAdd the support Library in your settings.gradle File. This library Jitpack is a novel package repository. It is made for JVM so that any library which is present in Github and Bitbucket can be directly used in the application.\ndependencyResolutionManagement {\n repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)\n repositories {\n google()\n mavenCentral()\n \n // add the following\n maven { url \"https://jitpack.io\" }\n }\n}\nAdd the below dependency in the dependencies section of your App/Module build.gradle File. It is a simple Android EditText with custom mask support. Mask EditText is directly imported and is customized according to the use.\ndependencies {\n implementation 'ru.egslava:MaskedEditText:1.0.5'\n}\nNow add the following code in the activity_main.xml file. It will create three mask EditTexts and one button in activity_main.xml.XML \n\n\n\nNow add the following code in the MainActivity File. All the three mask EditTexts and a button are defined. An onClickListener() is added on the button which creates a toast and shows all the data entered in the mask EditTexts.Java import androidx.appcompat.app.AppCompatActivity;\nimport android.os.Bundle;\nimport android.widget.Button;\nimport android.widget.Toast;\nimport br.com.sapereaude.maskedEditText.MaskedEditText;public class MainActivity extends AppCompatActivity {MaskedEditText creditCardText,phoneNumText,dateText;\nButton show;@Override\nprotected void onCreate(Bundle savedInstanceState) {\nsuper.onCreate(savedInstanceState);\nsetContentView(R.layout.activity_main);creditCardText = findViewById(R.id.card);\nphoneNumText = findViewById(R.id.phone);\ndateText = findViewById(R.id.Date);\nshow = findViewById(R.id.showButton);show.setOnClickListener(v -> {\n// Display the information from the EditText with help of Toasts\nToast.makeText(MainActivity.this, \"Credit Card Number \" + creditCardText.getText() + \"\\n Phone Number \"\n+ phoneNumText.getText() + \"\\n Date \" + dateText.getText(), Toast.LENGTH_LONG).show();\n});\n}\n}Kotlin import androidx.appcompat.app.AppCompatActivity\nimport android.os.Bundle\nimport android.widget.Button\nimport android.widget.Toast\nimport br.com.sapereaude.maskedEditText.MaskedEditTextclass MainActivity : AppCompatActivity() {lateinit var creditCardText: MaskedEditText\nlateinit var phoneNumText: MaskedEditText\nlateinit var dateText: MaskedEditText\nlateinit var show: Buttonoverride fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)creditCardText = findViewById(R.id.card)\nphoneNumText = findViewById(R.id.phone)\ndateText = findViewById(R.id.Date)\nshow = findViewById(R.id.showButton)show.setOnClickListener {\n// Display the information from the EditText with help of Toasts\nToast.makeText(this, (\"Credit Card Number \" + creditCardText.getText()) + \"\\n Phone Number \"\n+ phoneNumText.getText().toString() + \"\\n Date \" + dateText.getText(), Toast.LENGTH_LONG\n).show()\n}\n}\n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20200505162724/Record_2020-05-05-16-09-23_b64b62a768fef9e79b7cc5e52be67d20.mp4"
},
{
"instruction": "itText in Android?EditText is an android widget. It is a User Interface element used for entering and modifying data. It returns data in String format. Masking refers to the process of putting something in place of something else. Therefore by Masking an EditText, the blank space is replaced with some default text, known as Mask. This mask gets removed as soon as the user enters any character as input, and reappears when the text has been removed from the EditText. In this article, the masking is done with the help of JitPack Library, because it can be customized easily according to the need to implement various fields like phone number, date, etc. The code has been given in both Java and Kotlin Programming Language for Android.Approach:\nAdd the support Library in your settings.gradle File. This library Jitpack is a novel package repository. It is made for JVM so that any library which is present in Github and Bitbucket can be directly used in the application.\ndependencyResolutionManagement {\n repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)\n repositories {\n google()\n mavenCentral()\n \n // add the following\n maven { url \"https://jitpack.io\" }\n }\n}\nAdd the below dependency in the dependencies section of your App/Module build.gradle File. It is a simple Android EditText with custom mask support. Mask EditText is directly imported and is customized according to the use.\ndependencies {\n implementation 'ru.egslava:MaskedEditText:1.0.5'\n}\nNow add the following code in the activity_main.xml file. It will create three mask EditTexts and one button in activity_main.xml.XML \n\n\n\nNow add the following code in the MainActivity File. All the three mask EditTexts and a button are defined. An onClickListener() is added on the button which creates a toast and shows all the data entered in the mask EditTexts.Java import androidx.appcompat.app.AppCompatActivity;\nimport android.os.Bundle;\nimport android.widget.Button;\nimport android.widget.Toast;\nimport br.com.sapereaude.maskedEditText.MaskedEditText;public class MainActivity extends AppCompatActivity {MaskedEditText creditCardText,phoneNumText,dateText;\nButton show;@Override\nprotected void onCreate(Bundle savedInstanceState) {\nsuper.onCreate(savedInstanceState);\nsetContentView(R.layout.activity_main);creditCardText = findViewById(R.id.card);\nphoneNumText = findViewById(R.id.phone);\ndateText = findViewById(R.id.Date);\nshow = findViewById(R.id.showButton);show.setOnClickListener(v -> {\n// Display the information from the EditText with help of Toasts\nToast.makeText(MainActivity.this, \"Credit Card Number \" + creditCardText.getText() + \"\\n Phone Number \"\n+ phoneNumText.getText() + \"\\n Date \" + dateText.getText(), Toast.LENGTH_LONG).show();\n});\n}\n}Kotlin import androidx.appcompat.app.AppCompatActivity\nimport android.os.Bundle\nimport android.widget.Button\nimport android.widget.Toast\nimport br.com.sapereaude.maskedEditText.MaskedEditTextclass MainActivity : AppCompatActivity() {lateinit var creditCardText: MaskedEditText\nlateinit var phoneNumText: MaskedEditText\nlateinit var dateText: MaskedEditText\nlateinit var show: Buttonoverride fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)creditCardText = findViewById(R.id.card)\nphoneNumText = findViewById(R.id.phone)\ndateText = findViewById(R.id.Date)\nshow = findViewById(R.id.showButton)show.setOnClickListener {\n// Display the information from the EditText with help of Toasts\nToast.makeText(this, (\"Credit Card Number \" + creditCardText.getText()) + \"\\n Phone Number \"\n+ phoneNumText.getText().toString() + \"\\n Date \" + dateText.getText(), Toast.LENGTH_LONG\n).show()\n}\n}\n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20200505162724/Record_2020-05-05-16-09-23_b64b62a768fef9e79b7cc5e52be67d20.mp4",
"input": "",
"output": "sing Jetpack ComposeProgressBar is a material UI component in Android which is used to indicate the progress of any process such as for showing any downloading procedure, as a placeholder screen, and many more. In this article, we will take a look at the implementation of ProressBar in Android using Jetpack Compose.AttributesUsesmodifier\nto add padding to our progress Bar.color\nto add color to our progress Bar.strokeWidth\nthis attribute is used to give the width of the circular line of the progress Bar.progress\nto indicate the progress of your circular progress Bar.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in the Android Studio Canary Version please refer to How to Create a new Project in Android Studio Canary Version with Jetpack Compose.\nStep 2: Working with the MainActivity.kt file\nNavigate to the app > java > your app\u2019s package name and open the MainActivity.kt file. Inside that file add the below code to it. Comments are added inside the code to understand the code in more detail.Kotlin import android.graphics.drawable.shapes.Shape\nimport android.media.Image\nimport android.os.Bundle\nimport android.widget.Toast\nimport androidx.appcompat.app.AppCompatActivity\nimport androidx.compose.foundation.*\nimport androidx.compose.foundation.Text\nimport androidx.compose.foundation.layout.*\nimport androidx.compose.foundation.shape.CircleShape\nimport androidx.compose.foundation.shape.RoundedCornerShape\nimport androidx.compose.foundation.text.KeyboardOptions\nimport androidx.compose.material.*\nimport androidx.compose.material.Icon\nimport androidx.compose.material.icons.Icons\nimport androidx.compose.material.icons.filled.AccountCircle\nimport androidx.compose.material.icons.filled.Info\nimport androidx.compose.material.icons.filled.Menu\nimport androidx.compose.material.icons.filled.Phone\nimport androidx.compose.runtime.*\nimport androidx.compose.runtime.savedinstancestate.savedInstanceState\nimport androidx.compose.ui.Alignment\nimport androidx.compose.ui.layout.ContentScale\nimport androidx.compose.ui.platform.setContent\nimport androidx.compose.ui.res.imageResource\nimport androidx.compose.ui.tooling.preview.Preview\nimport androidx.compose.ui.unit.dp\nimport com.example.gfgapp.ui.GFGAppTheme\nimport androidx.compose.ui.Modifier\nimport androidx.compose.ui.draw.clip\nimport androidx.compose.ui.graphics.Color\nimport androidx.compose.ui.graphics.SolidColor\nimport androidx.compose.ui.platform.ContextAmbient\nimport androidx.compose.ui.platform.testTag\nimport androidx.compose.ui.res.colorResource\nimport androidx.compose.ui.semantics.SemanticsProperties.ToggleableState\nimport androidx.compose.ui.text.TextStyle\nimport androidx.compose.ui.text.font.FontFamily\nimport androidx.compose.ui.text.input.*\nimport androidx.compose.ui.unit.Dp\nimport androidx.compose.ui.unit.TextUnitclass MainActivity : AppCompatActivity() {\noverride fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContent {\nColumn {\n// in below line we are calling \n// a progress bar method.\nSimpleCircularProgressComponent()\n}\n}\n}\n}@Preview(showBackground = true)\n@Composable\nfun DefaultPreview() {\nGFGAppTheme {\nSimpleCircularProgressComponent();\n}\n}@Composable\nfun SimpleCircularProgressComponent() {\n// CircularProgressIndicator is generally used\n// at the loading screen and it indicates that\n// some progress is going on so please wait.\nColumn(\n// we are using column to align our\n// imageview to center of the screen.\nmodifier = Modifier.fillMaxWidth().fillMaxHeight(),// below line is used for specifying\n// vertical arrangement.\nverticalArrangement = Arrangement.Center,// below line is used for specifying\n// horizontal arrangement.\nhorizontalAlignment = Alignment.CenterHorizontally,) {\n// below line is use to display \n// a circular progress bar.\nCircularProgressIndicator(\n// below line is use to add padding\n// to our progress bar.\nmodifier = Modifier.padding(16.dp),// below line is use to add color \n// to our progress bar.\ncolor = colorResource(id = R.color.purple_200),// below line is use to add stroke \n// width to our progress bar.\nstrokeWidth = Dp(value = 4F)\n)\n}\n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210118220656/Screenrecorder-2021-01-18-22-05-28-34.mp4"
},
{
"instruction": "sing Jetpack ComposeProgressBar is a material UI component in Android which is used to indicate the progress of any process such as for showing any downloading procedure, as a placeholder screen, and many more. In this article, we will take a look at the implementation of ProressBar in Android using Jetpack Compose.AttributesUsesmodifier\nto add padding to our progress Bar.color\nto add color to our progress Bar.strokeWidth\nthis attribute is used to give the width of the circular line of the progress Bar.progress\nto indicate the progress of your circular progress Bar.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in the Android Studio Canary Version please refer to How to Create a new Project in Android Studio Canary Version with Jetpack Compose.\nStep 2: Working with the MainActivity.kt file\nNavigate to the app > java > your app\u2019s package name and open the MainActivity.kt file. Inside that file add the below code to it. Comments are added inside the code to understand the code in more detail.Kotlin import android.graphics.drawable.shapes.Shape\nimport android.media.Image\nimport android.os.Bundle\nimport android.widget.Toast\nimport androidx.appcompat.app.AppCompatActivity\nimport androidx.compose.foundation.*\nimport androidx.compose.foundation.Text\nimport androidx.compose.foundation.layout.*\nimport androidx.compose.foundation.shape.CircleShape\nimport androidx.compose.foundation.shape.RoundedCornerShape\nimport androidx.compose.foundation.text.KeyboardOptions\nimport androidx.compose.material.*\nimport androidx.compose.material.Icon\nimport androidx.compose.material.icons.Icons\nimport androidx.compose.material.icons.filled.AccountCircle\nimport androidx.compose.material.icons.filled.Info\nimport androidx.compose.material.icons.filled.Menu\nimport androidx.compose.material.icons.filled.Phone\nimport androidx.compose.runtime.*\nimport androidx.compose.runtime.savedinstancestate.savedInstanceState\nimport androidx.compose.ui.Alignment\nimport androidx.compose.ui.layout.ContentScale\nimport androidx.compose.ui.platform.setContent\nimport androidx.compose.ui.res.imageResource\nimport androidx.compose.ui.tooling.preview.Preview\nimport androidx.compose.ui.unit.dp\nimport com.example.gfgapp.ui.GFGAppTheme\nimport androidx.compose.ui.Modifier\nimport androidx.compose.ui.draw.clip\nimport androidx.compose.ui.graphics.Color\nimport androidx.compose.ui.graphics.SolidColor\nimport androidx.compose.ui.platform.ContextAmbient\nimport androidx.compose.ui.platform.testTag\nimport androidx.compose.ui.res.colorResource\nimport androidx.compose.ui.semantics.SemanticsProperties.ToggleableState\nimport androidx.compose.ui.text.TextStyle\nimport androidx.compose.ui.text.font.FontFamily\nimport androidx.compose.ui.text.input.*\nimport androidx.compose.ui.unit.Dp\nimport androidx.compose.ui.unit.TextUnitclass MainActivity : AppCompatActivity() {\noverride fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContent {\nColumn {\n// in below line we are calling \n// a progress bar method.\nSimpleCircularProgressComponent()\n}\n}\n}\n}@Preview(showBackground = true)\n@Composable\nfun DefaultPreview() {\nGFGAppTheme {\nSimpleCircularProgressComponent();\n}\n}@Composable\nfun SimpleCircularProgressComponent() {\n// CircularProgressIndicator is generally used\n// at the loading screen and it indicates that\n// some progress is going on so please wait.\nColumn(\n// we are using column to align our\n// imageview to center of the screen.\nmodifier = Modifier.fillMaxWidth().fillMaxHeight(),// below line is used for specifying\n// vertical arrangement.\nverticalArrangement = Arrangement.Center,// below line is used for specifying\n// horizontal arrangement.\nhorizontalAlignment = Alignment.CenterHorizontally,) {\n// below line is use to display \n// a circular progress bar.\nCircularProgressIndicator(\n// below line is use to add padding\n// to our progress bar.\nmodifier = Modifier.padding(16.dp),// below line is use to add color \n// to our progress bar.\ncolor = colorResource(id = R.color.purple_200),// below line is use to add stroke \n// width to our progress bar.\nstrokeWidth = Dp(value = 4F)\n)\n}\n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210118220656/Screenrecorder-2021-01-18-22-05-28-34.mp4",
"input": "",
"output": "routinesPrerequisite: Kotlin Coroutines on Android\nIt is known that coroutines are always started in a specific context, and that context describes in which threads the coroutine will be started in. In general, we can start the coroutine using GlobalScope without passing any parameters to it, this is done when we are not specifying the thread in which the coroutine should be launch. This method does not give us much control over it, as our coroutine can be launched in any thread available, due to which it is not possible to predict the thread in which our coroutines have been launched.Kotlin class MainActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // coroutine launched in GlobalScope \nGlobalScope.launch() { \nLog.i(\"Inside Global Scope \",Thread.currentThread().name.toString()) \n// getting the name of thread in \n// which our coroutine has been launched \n} Log.i(\"Main Activity \",Thread.currentThread().name.toString()) \n} \n}log output is shown below:We can see that the thread in which the coroutine is launched cannot be predicted, sometimes it is DefaultDispatcher-worker-1, or DefaultDispatcher-worker-2 or DefaultDispatcher-worker-3.\nHow Dispatchers solve the above problem?\nDispatchers help coroutines in deciding the thread on which the work has to be done. Dispatchers are passed as the arguments to the GlobalScope by mentioning which type of dispatchers we can use depending on the work that we want the coroutine to do.\nTypes of Dispatchers\nThere are majorly 4 types of Dispatchers.Main Dispatcher\nIO Dispatcher\nDefault Dispatcher\nUnconfined DispatcherMain Dispatcher:\nIt starts the coroutine in the main thread. It is mostly used when we need to perform the UI operations within the coroutine, as UI can only be changed from the main thread(also called the UI thread).Kotlin GlobalScope.launch(Dispatchers.Main) { \nLog.i(\"Inside Global Scope \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())IO Dispatcher:\nIt starts the coroutine in the IO thread, it is used to perform all the data operations such as networking, reading, or writing from the database, reading, or writing to the files eg: Fetching data from the database is an IO operation, which is done on the IO thread.Kotlin GlobalScope.launch(Dispatchers.IO) { \nLog.i(\"Inside IO dispatcher \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())Default Dispatcher:\nIt starts the coroutine in the Default Thread. We should choose this when we are planning to do Complex and long-running calculations, which can block the main thread and freeze the UI eg: Suppose we need to do the 10,000 calculations and we are doing all these calculations on the UI thread ie main thread, and if we wait for the result or 10,000 calculations, till that time our main thread would be blocked, and our UI will be frozen, leading to poor user experience. So in this case we need to use the Default Thread. The default dispatcher that is used when coroutines are launched in GlobalScope is represented by Dispatchers. Default and uses a shared background pool of threads, so launch(Dispatchers.Default) { \u2026 } uses the same dispatcher as GlobalScope.launch { \u2026 }.Kotlin GlobalScope.launch(Dispatchers.Default) { \nLog.i(\"Inside Default dispatcher \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())Unconfined Dispatcher:\nAs the name suggests unconfined dispatcher is not confined to any specific thread. It executes the initial continuation of a coroutine in the current call-frame and lets the coroutine resume in whatever thread that is used by the corresponding suspending function, without mandating any specific threading policy."
},
{
"instruction": "routinesPrerequisite: Kotlin Coroutines on Android\nIt is known that coroutines are always started in a specific context, and that context describes in which threads the coroutine will be started in. In general, we can start the coroutine using GlobalScope without passing any parameters to it, this is done when we are not specifying the thread in which the coroutine should be launch. This method does not give us much control over it, as our coroutine can be launched in any thread available, due to which it is not possible to predict the thread in which our coroutines have been launched.Kotlin class MainActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // coroutine launched in GlobalScope \nGlobalScope.launch() { \nLog.i(\"Inside Global Scope \",Thread.currentThread().name.toString()) \n// getting the name of thread in \n// which our coroutine has been launched \n} Log.i(\"Main Activity \",Thread.currentThread().name.toString()) \n} \n}log output is shown below:We can see that the thread in which the coroutine is launched cannot be predicted, sometimes it is DefaultDispatcher-worker-1, or DefaultDispatcher-worker-2 or DefaultDispatcher-worker-3.\nHow Dispatchers solve the above problem?\nDispatchers help coroutines in deciding the thread on which the work has to be done. Dispatchers are passed as the arguments to the GlobalScope by mentioning which type of dispatchers we can use depending on the work that we want the coroutine to do.\nTypes of Dispatchers\nThere are majorly 4 types of Dispatchers.Main Dispatcher\nIO Dispatcher\nDefault Dispatcher\nUnconfined DispatcherMain Dispatcher:\nIt starts the coroutine in the main thread. It is mostly used when we need to perform the UI operations within the coroutine, as UI can only be changed from the main thread(also called the UI thread).Kotlin GlobalScope.launch(Dispatchers.Main) { \nLog.i(\"Inside Global Scope \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())IO Dispatcher:\nIt starts the coroutine in the IO thread, it is used to perform all the data operations such as networking, reading, or writing from the database, reading, or writing to the files eg: Fetching data from the database is an IO operation, which is done on the IO thread.Kotlin GlobalScope.launch(Dispatchers.IO) { \nLog.i(\"Inside IO dispatcher \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())Default Dispatcher:\nIt starts the coroutine in the Default Thread. We should choose this when we are planning to do Complex and long-running calculations, which can block the main thread and freeze the UI eg: Suppose we need to do the 10,000 calculations and we are doing all these calculations on the UI thread ie main thread, and if we wait for the result or 10,000 calculations, till that time our main thread would be blocked, and our UI will be frozen, leading to poor user experience. So in this case we need to use the Default Thread. The default dispatcher that is used when coroutines are launched in GlobalScope is represented by Dispatchers. Default and uses a shared background pool of threads, so launch(Dispatchers.Default) { \u2026 } uses the same dispatcher as GlobalScope.launch { \u2026 }.Kotlin GlobalScope.launch(Dispatchers.Default) { \nLog.i(\"Inside Default dispatcher \",Thread.currentThread().name.toString()) \n// getting the name of thread in which \n// our coroutine has been launched \n} \nLog.i(\"Main Activity \",Thread.currentThread().name.toString())Unconfined Dispatcher:\nAs the name suggests unconfined dispatcher is not confined to any specific thread. It executes the initial continuation of a coroutine in the current call-frame and lets the coroutine resume in whatever thread that is used by the corresponding suspending function, without mandating any specific threading policy.",
"input": "",
"output": "droid using Jetpack ComposeCircular ImageView is used in many of the apps. These types of images are generally used to represent the profile picture of the user and many more images. We have seen the implementation of ImageView in Android using Jetpack Compose. In this article, we will take a look at the implementation of Circle ImageView in Android using Jetpack Compose. \nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in the Android Studio Canary Version please refer to How to Create a new Project in Android Studio Canary Version with Jetpack Compose.\nStep 2: Add an Image to the drawable folder\nAfter creating a new project we have to add an image inside our drawable folder for displaying that image inside our ImageView. Copy your image from your folder\u2019s location and go inside our project. Inside our project Navigate to the app > res > drawable > Right-click on the drawable folder and paste your image there. \nStep 3: Working with the MainActivity.kt file\nAfter adding this image navigates to the app > java > MainActivity.kt and add the below code to it. Comments are added inside the code to understand the code in more detail.Kotlin import android.graphics.drawable.shapes.Shape \nimport android.media.Image \nimport android.os.Bundle \nimport android.widget.Toast \nimport androidx.appcompat.app.AppCompatActivity \nimport androidx.compose.foundation.BorderStroke \nimport androidx.compose.foundation.Image \nimport androidx.compose.foundation.InteractionState \nimport androidx.compose.foundation.Text \nimport androidx.compose.foundation.layout.* \nimport androidx.compose.foundation.shape.CircleShape \nimport androidx.compose.foundation.shape.RoundedCornerShape \nimport androidx.compose.foundation.text.KeyboardOptions \nimport androidx.compose.material.* \nimport androidx.compose.material.icons.Icons \nimport androidx.compose.material.icons.filled.AccountCircle \nimport androidx.compose.material.icons.filled.Info \nimport androidx.compose.material.icons.filled.Phone \nimport androidx.compose.runtime.* \nimport androidx.compose.runtime.savedinstancestate.savedInstanceState \nimport androidx.compose.ui.Alignment \nimport androidx.compose.ui.layout.ContentScale \nimport androidx.compose.ui.platform.setContent \nimport androidx.compose.ui.res.imageResource \nimport androidx.compose.ui.tooling.preview.Preview \nimport androidx.compose.ui.unit.dp \nimport com.example.gfgapp.ui.GFGAppTheme \nimport androidx.compose.ui.Modifier \nimport androidx.compose.ui.draw.clip \nimport androidx.compose.ui.graphics.Color \nimport androidx.compose.ui.graphics.SolidColor \nimport androidx.compose.ui.platform.ContextAmbient \nimport androidx.compose.ui.platform.testTag \nimport androidx.compose.ui.res.colorResource \nimport androidx.compose.ui.text.TextStyle \nimport androidx.compose.ui.text.font.FontFamily \nimport androidx.compose.ui.text.input.* \nimport androidx.compose.ui.unit.Dp \nimport androidx.compose.ui.unit.TextUnit class MainActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContent { \nGFGAppTheme { \n// A surface container using the 'background' color from the theme \nSurface(color = MaterialTheme.colors.background) { \n// at below line we are calling \n// our function for button. \nCircleImg(); \n} \n} \n} \n} \n} @Preview(showBackground = true) \n@Composable\nfun DefaultPreview() { \nGFGAppTheme { \nCircleImg(); \n} \n} @Composable\nfun CircleImg() { Column( // we are using column to align our imageview \n// to center of the screen. \nmodifier = Modifier.fillMaxWidth().fillMaxHeight(), // below line is used for specifying \n// vertical arrangement. \nverticalArrangement = Arrangement.Center, // below line is used for specifying \n// horizontal arrangement. \nhorizontalAlignment = Alignment.CenterHorizontally, ) { \n// creating a card for creating a circle image view. \nCard( \n// below line is use to add size to our image view and \n// test tag is use to add tag to our image. \nmodifier = Modifier.preferredSize(100.dp).testTag(tag = \"circle\"), // below line is use to \n// add shape to our image view. \nshape = CircleShape, // below line is use to add \n// elevation to our image view. \nelevation = 12.dp \n) { \n// below line we are creating a new image. \nImage( \n// in below line we are providing image \n// resource from drawable folder. \nimageResource(id = R.drawable.gfgimage), // below line is use to give scaling \n// to our image view. \ncontentScale = ContentScale.Crop, // below line is use to add modifier \n// to our image view. \nmodifier = Modifier.fillMaxSize() \n) \n} \n} \n}Now run your app and see the output of the app.\nOutput:"
},
{
"instruction": "droid using Jetpack ComposeCircular ImageView is used in many of the apps. These types of images are generally used to represent the profile picture of the user and many more images. We have seen the implementation of ImageView in Android using Jetpack Compose. In this article, we will take a look at the implementation of Circle ImageView in Android using Jetpack Compose. \nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in the Android Studio Canary Version please refer to How to Create a new Project in Android Studio Canary Version with Jetpack Compose.\nStep 2: Add an Image to the drawable folder\nAfter creating a new project we have to add an image inside our drawable folder for displaying that image inside our ImageView. Copy your image from your folder\u2019s location and go inside our project. Inside our project Navigate to the app > res > drawable > Right-click on the drawable folder and paste your image there. \nStep 3: Working with the MainActivity.kt file\nAfter adding this image navigates to the app > java > MainActivity.kt and add the below code to it. Comments are added inside the code to understand the code in more detail.Kotlin import android.graphics.drawable.shapes.Shape \nimport android.media.Image \nimport android.os.Bundle \nimport android.widget.Toast \nimport androidx.appcompat.app.AppCompatActivity \nimport androidx.compose.foundation.BorderStroke \nimport androidx.compose.foundation.Image \nimport androidx.compose.foundation.InteractionState \nimport androidx.compose.foundation.Text \nimport androidx.compose.foundation.layout.* \nimport androidx.compose.foundation.shape.CircleShape \nimport androidx.compose.foundation.shape.RoundedCornerShape \nimport androidx.compose.foundation.text.KeyboardOptions \nimport androidx.compose.material.* \nimport androidx.compose.material.icons.Icons \nimport androidx.compose.material.icons.filled.AccountCircle \nimport androidx.compose.material.icons.filled.Info \nimport androidx.compose.material.icons.filled.Phone \nimport androidx.compose.runtime.* \nimport androidx.compose.runtime.savedinstancestate.savedInstanceState \nimport androidx.compose.ui.Alignment \nimport androidx.compose.ui.layout.ContentScale \nimport androidx.compose.ui.platform.setContent \nimport androidx.compose.ui.res.imageResource \nimport androidx.compose.ui.tooling.preview.Preview \nimport androidx.compose.ui.unit.dp \nimport com.example.gfgapp.ui.GFGAppTheme \nimport androidx.compose.ui.Modifier \nimport androidx.compose.ui.draw.clip \nimport androidx.compose.ui.graphics.Color \nimport androidx.compose.ui.graphics.SolidColor \nimport androidx.compose.ui.platform.ContextAmbient \nimport androidx.compose.ui.platform.testTag \nimport androidx.compose.ui.res.colorResource \nimport androidx.compose.ui.text.TextStyle \nimport androidx.compose.ui.text.font.FontFamily \nimport androidx.compose.ui.text.input.* \nimport androidx.compose.ui.unit.Dp \nimport androidx.compose.ui.unit.TextUnit class MainActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContent { \nGFGAppTheme { \n// A surface container using the 'background' color from the theme \nSurface(color = MaterialTheme.colors.background) { \n// at below line we are calling \n// our function for button. \nCircleImg(); \n} \n} \n} \n} \n} @Preview(showBackground = true) \n@Composable\nfun DefaultPreview() { \nGFGAppTheme { \nCircleImg(); \n} \n} @Composable\nfun CircleImg() { Column( // we are using column to align our imageview \n// to center of the screen. \nmodifier = Modifier.fillMaxWidth().fillMaxHeight(), // below line is used for specifying \n// vertical arrangement. \nverticalArrangement = Arrangement.Center, // below line is used for specifying \n// horizontal arrangement. \nhorizontalAlignment = Alignment.CenterHorizontally, ) { \n// creating a card for creating a circle image view. \nCard( \n// below line is use to add size to our image view and \n// test tag is use to add tag to our image. \nmodifier = Modifier.preferredSize(100.dp).testTag(tag = \"circle\"), // below line is use to \n// add shape to our image view. \nshape = CircleShape, // below line is use to add \n// elevation to our image view. \nelevation = 12.dp \n) { \n// below line we are creating a new image. \nImage( \n// in below line we are providing image \n// resource from drawable folder. \nimageResource(id = R.drawable.gfgimage), // below line is use to give scaling \n// to our image view. \ncontentScale = ContentScale.Crop, // below line is use to add modifier \n// to our image view. \nmodifier = Modifier.fillMaxSize() \n) \n} \n} \n}Now run your app and see the output of the app.\nOutput:",
"input": "",
"output": "Android ImageSwitcher is a user interface widget that provides a smooth transition animation effect to the images while switching between them to display in the view.\nImageSwitcher is subclass of View Switcher which is used to animates one image and displays next one.Generally, we use ImageSwitcher in two ways manually in XML layout and programmatically in Kotlin file.\nWe should define an XML component, to use ImageSwitcher in our android application.XML \n First we create a new project by following the below steps:Click on File, then New => New Project.\nAfter that include the Kotlin support and click on next.\nSelect the minimum SDK as per convenience and click next button.\nThen select the Empty activity => next => finish.Different attributes of ImageSwitcher widgetXML attributes\nDescriptionandroid:id\nUsed to specify the id of the view.android:onClick\nUsed to specify the action when this view is clicked.android:background\nUsed to set the background of the view.android:padding\nUsed to set the padding of the view.android:visibility\nUsed to set the visibility of the view.android:inAnimation\nUsed to define the animation to use when view is shown.android:outAnimation\nUsed to define the animation to use when view is hidden.android:animateFirstView\nUsed to define whether to animate the current view when the view animation is first displayed.Modify activity_main.xml file\nIn this file, we use constraint layout with ImageSwitcher and Buttons.XML \n \nImageSwitcherInKotlin \nNext \nPrev \n Different methods of ImageSwitcher widgetMethods\nDescriptionsetImageDrawable\nIt is used to set a new drawable on the next ImageView in the switcher.setImageResource\nIt is used to set a new image on the ImageSwitcher with the given resource id.setImageURI\nIt is used to set a new image on the ImageSwitcher with the given URI.Access ImageSwitcher in MainActivity.kt file\nFirst, we declare an array flowers which contains the resource of the images used for the ImageView.\nprivate val flowers = intArrayOf(R.drawable.flower1,\n R.drawable.flower2, R.drawable.flower4)\nthen, we access the ImageSwitcher from the XML layout and set ImageView to display the image.\nval imgSwitcher = findViewById(R.id.imgSw)\nimgSwitcher?.setFactory({\n val imgView = ImageView(applicationContext)\n imgView.scaleType = ImageView.ScaleType.FIT_CENTER\n imgView.setPadding(8, 8, 8, 8)\n imgView\n })\nAlso, we will use one of the above method for ImageSwitcher.\nimgSwitcher?.setImageResource(flowers[index])Kotlin package com.geeksforgeeks.myfirstkotlinapp import androidx.appcompat.app.AppCompatActivity import android.os.Bundle \nimport android.view.animation.AnimationUtils \nimport android.widget.Button \nimport android.widget.ImageSwitcher \nimport android.widget.ImageView class MainActivity : AppCompatActivity() { private val flowers = intArrayOf(R.drawable.flower1, \nR.drawable.flower2, R.drawable.flower4) \nprivate var index = 0override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // access the ImageSwitcher \nval imgSwitcher = findViewById(R.id.imgSw) imgSwitcher?.setFactory({ \nval imgView = ImageView(applicationContext) \nimgView.scaleType = ImageView.ScaleType.FIT_CENTER \nimgView.setPadding(8, 8, 8, 8) \nimgView \n}) // set the method and pass array as a parameter \nimgSwitcher?.setImageResource(flowers[index]) val imgIn = AnimationUtils.loadAnimation( \nthis, android.R.anim.slide_in_left) \nimgSwitcher?.inAnimation = imgIn val imgOut = AnimationUtils.loadAnimation( \nthis, android.R.anim.slide_out_right) \nimgSwitcher?.outAnimation = imgOut // previous button functionality \nval prev = findViewById(R.id.prev) \nprev.setOnClickListener { \nindex = if (index - 1 >= 0) index - 1 else 2\nimgSwitcher?.setImageResource(flowers[index]) \n} \n// next button functionality \nval next = findViewById(R.id.next) \nnext.setOnClickListener { \nindex = if (index + 1 < flowers.size) index +1 else 0\nimgSwitcher?.setImageResource(flowers[index]) \n} \n} \n} AndroidManifest.xml fileXML \n \n \n \n \n \n Run as Emulator:\nClick next button then we get the other animated image in the View."
},
{
"instruction": "Android ImageSwitcher is a user interface widget that provides a smooth transition animation effect to the images while switching between them to display in the view.\nImageSwitcher is subclass of View Switcher which is used to animates one image and displays next one.Generally, we use ImageSwitcher in two ways manually in XML layout and programmatically in Kotlin file.\nWe should define an XML component, to use ImageSwitcher in our android application.XML \n First we create a new project by following the below steps:Click on File, then New => New Project.\nAfter that include the Kotlin support and click on next.\nSelect the minimum SDK as per convenience and click next button.\nThen select the Empty activity => next => finish.Different attributes of ImageSwitcher widgetXML attributes\nDescriptionandroid:id\nUsed to specify the id of the view.android:onClick\nUsed to specify the action when this view is clicked.android:background\nUsed to set the background of the view.android:padding\nUsed to set the padding of the view.android:visibility\nUsed to set the visibility of the view.android:inAnimation\nUsed to define the animation to use when view is shown.android:outAnimation\nUsed to define the animation to use when view is hidden.android:animateFirstView\nUsed to define whether to animate the current view when the view animation is first displayed.Modify activity_main.xml file\nIn this file, we use constraint layout with ImageSwitcher and Buttons.XML \n \nImageSwitcherInKotlin \nNext \nPrev \n Different methods of ImageSwitcher widgetMethods\nDescriptionsetImageDrawable\nIt is used to set a new drawable on the next ImageView in the switcher.setImageResource\nIt is used to set a new image on the ImageSwitcher with the given resource id.setImageURI\nIt is used to set a new image on the ImageSwitcher with the given URI.Access ImageSwitcher in MainActivity.kt file\nFirst, we declare an array flowers which contains the resource of the images used for the ImageView.\nprivate val flowers = intArrayOf(R.drawable.flower1,\n R.drawable.flower2, R.drawable.flower4)\nthen, we access the ImageSwitcher from the XML layout and set ImageView to display the image.\nval imgSwitcher = findViewById(R.id.imgSw)\nimgSwitcher?.setFactory({\n val imgView = ImageView(applicationContext)\n imgView.scaleType = ImageView.ScaleType.FIT_CENTER\n imgView.setPadding(8, 8, 8, 8)\n imgView\n })\nAlso, we will use one of the above method for ImageSwitcher.\nimgSwitcher?.setImageResource(flowers[index])Kotlin package com.geeksforgeeks.myfirstkotlinapp import androidx.appcompat.app.AppCompatActivity import android.os.Bundle \nimport android.view.animation.AnimationUtils \nimport android.widget.Button \nimport android.widget.ImageSwitcher \nimport android.widget.ImageView class MainActivity : AppCompatActivity() { private val flowers = intArrayOf(R.drawable.flower1, \nR.drawable.flower2, R.drawable.flower4) \nprivate var index = 0override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) // access the ImageSwitcher \nval imgSwitcher = findViewById(R.id.imgSw) imgSwitcher?.setFactory({ \nval imgView = ImageView(applicationContext) \nimgView.scaleType = ImageView.ScaleType.FIT_CENTER \nimgView.setPadding(8, 8, 8, 8) \nimgView \n}) // set the method and pass array as a parameter \nimgSwitcher?.setImageResource(flowers[index]) val imgIn = AnimationUtils.loadAnimation( \nthis, android.R.anim.slide_in_left) \nimgSwitcher?.inAnimation = imgIn val imgOut = AnimationUtils.loadAnimation( \nthis, android.R.anim.slide_out_right) \nimgSwitcher?.outAnimation = imgOut // previous button functionality \nval prev = findViewById(R.id.prev) \nprev.setOnClickListener { \nindex = if (index - 1 >= 0) index - 1 else 2\nimgSwitcher?.setImageResource(flowers[index]) \n} \n// next button functionality \nval next = findViewById(R.id.next) \nnext.setOnClickListener { \nindex = if (index + 1 < flowers.size) index +1 else 0\nimgSwitcher?.setImageResource(flowers[index]) \n} \n} \n} AndroidManifest.xml fileXML \n \n \n \n \n \n Run as Emulator:\nClick next button then we get the other animated image in the View.",
"input": "",
"output": "h Dagger 2 in AndroidIf there are two classes, class A and class B and class A depends on class B then class B is called dependent for class A.So, Every time we want to access class B in class A we need to create an instance of class B in Class A or use static factory methods to access class A. But this will make our code tight coupled, difficult to manage, and test. In order to remove these problems, we use dependency injection. Dependency Injection is a design pattern that removes the dependency from the programming code and makes the application easy to manage and test. It also makes programming code loosely coupled.\nDependency Injection in Android\nLet us assume, we want to store some data in SharedPreferences. In order to save or retrieve shared preferences data, we need the instance of shared preference in our Activity\u2019s boilerplate code. And it may lead to problems in testing, managing, etc. if our codebase is large. This is where Android Dependency Injection helps. Here, SharedPreferences acts as a dependency for our Activity so, we don\u2019t create its instance in our activity rather we inject it from some other class. Below is an illustration of the situation.Dagger 2\nDagger 2 is a compile-time android dependency injection framework that uses Java Specification Request 330 and Annotations. Some of the basic annotations that are used in dagger 2 are:@Module This annotation is used over the class which is used to construct objects and provide the dependencies.\n@Provides This is used over the method in the module class that will return the object.\n@Inject This is used over the fields, constructor, or method and indicate that dependencies are requested.\n@Component This is used over a component interface which acts as a bridge between @Module and @Inject. (Module class doesn\u2019t provide dependency directly to requesting class, it uses component interface)\n@Singleton This is used to indicate only a single instance of dependency object is created.Example\nIn this example, we will add some data to shared preferences and then retrieve it from there using the dagger 2 library. Below is the picture of what we are going to do in this example. Note that we are going to implement this project using the Java language.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Adding Dependencies\nIn order to use dependency injection with the help of dagger 2 libraries, we need to add it\u2019s dependency. Go to Gradle Scripts > build.gradle(Module: app) and add the following dependencies. After adding these dependencies you need to click on Sync Now.dependencies {\n implementation \u201ccom.google.dagger:hilt-core:2.29-alpha\u201d\n annotationProcessor \u201ccom.google.dagger:hilt-compiler:2.29-alpha\u201d\n}Before moving further let\u2019s add some color attributes in order to enhance the app bar. Go to app > res > values > colors.xml and add the following color attributes. XML \n#0F9D58 \n#16E37F \n#03DAC5 \n Step 3: Working with the activity_main.xml file\nIn this step, we will create a layout file for the application. We have used EditText for taking the input from the user and a TextView for presenting the output and save and show buttons respectively. Below is the code snippet for the activity_main.xml file.XML \n \n#0F9D58 \n#16E37F \n#03DAC5 \n Step 3: Working with the activity_main.xml file\nIn this step, we will create a layout file for the application. We have used EditText for taking the input from the user and a TextView for presenting the output and save and show buttons respectively. Below is the code snippet for the activity_main.xml file.XML \n \n Step 3: Modify MainActivity.java file\nIn this section, let\u2019s design the backend of the application. Go to MainActivity.java. Now in the java file create a string array and store the values you want to display in the list. Also, create an object of ListView class. In onCreate() method find Listview by id using findViewById() method. Create an object of ArrayAdapter using a new keyword followed by a constructor call. The ArrayAdaptor public constructor description is below:\npublic ArrayAdapter (Context context, int Resource, T[ ] objects)ParameterDescriptioncontext\ncurrent contextResource\nthe resource ID for a layout fileobjects\nobjects to display in the ListViewAccording to this pass the argument in ArrayAdapter Constructor and create an object. At last, conjoin the adapter with the list using setAdapter() method.MainActivity.java import androidx.appcompat.app.AppCompatActivity; \nimport android.os.Bundle; \nimport android.widget.AdapterView; \nimport android.widget.ArrayAdapter; \nimport android.widget.ListView; public class MainActivity extends AppCompatActivity { ListView l; \nString tutorials[] \n= { \"Algorithms\", \"Data Structures\", \n\"Languages\", \"Interview Corner\", \n\"GATE\", \"ISRO CS\", \n\"UGC NET CS\", \"CS Subjects\", \n\"Web Technologies\" }; @Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); \nl = findViewById(R.id.list); \nArrayAdapter arr; \narr \n= new ArrayAdapter( \nthis, \nR.layout.support_simple_spinner_dropdown_item, \ntutorials); \nl.setAdapter(arr); \n} \n} Output"
},
{
"instruction": " with ExampleA ListView is a type of AdapterView that displays a vertical list of scroll-able views and each view is placed one below the other. Using adapter, items are inserted into the list from an array or database. For displaying the items in the list method setAdaptor() is used. setAdaptor() method conjoins an adapter with the list.\nAndroid ListView is a ViewGroup that is used to display the list of items in multiple rows and contains an adapter that automatically inserts the items into the list.\nThe main purpose of the adapter is to fetch data from an array or database and insert each item that placed into the list for the desired result. So, it is the main source to pull data from strings.xml file which contains all the required strings in Java or XML files.\nXML Attributes of ListViewAttributeDescriptionandroid:divider\nA color or drawable to separate list items.android:dividerHeight\nDivider\u2019s height.android:entries\nReference to an array resource that will populate the ListView.android:footerDividersEnabled\nWhen set to false, the ListView will not draw the divider before each footer view.android:headerDividersEnabled\nWhen set to false, the ListView will not draw the divider before each header view.How to add a ListView in an Android App\nNow let\u2019s understand how to use a listview in an android application with an example. In the example, let\u2019s create an android application that will display a list of tutorials available in GeeksforGeeks portal.\nStep 1: Create a new projectClick on File, then New => New Project.\nChoose \u201cEmpty Activity\u201d for the project template.\nSelect language as Java.\nSelect the minimum SDK as per your need.Step 2: Modify activity_main.xml file\nAdd a ListView in the activity_main.xml file.activity_main.xml \n \n Step 3: Modify MainActivity.java file\nIn this section, let\u2019s design the backend of the application. Go to MainActivity.java. Now in the java file create a string array and store the values you want to display in the list. Also, create an object of ListView class. In onCreate() method find Listview by id using findViewById() method. Create an object of ArrayAdapter using a new keyword followed by a constructor call. The ArrayAdaptor public constructor description is below:\npublic ArrayAdapter (Context context, int Resource, T[ ] objects)ParameterDescriptioncontext\ncurrent contextResource\nthe resource ID for a layout fileobjects\nobjects to display in the ListViewAccording to this pass the argument in ArrayAdapter Constructor and create an object. At last, conjoin the adapter with the list using setAdapter() method.MainActivity.java import androidx.appcompat.app.AppCompatActivity; \nimport android.os.Bundle; \nimport android.widget.AdapterView; \nimport android.widget.ArrayAdapter; \nimport android.widget.ListView; public class MainActivity extends AppCompatActivity { ListView l; \nString tutorials[] \n= { \"Algorithms\", \"Data Structures\", \n\"Languages\", \"Interview Corner\", \n\"GATE\", \"ISRO CS\", \n\"UGC NET CS\", \"CS Subjects\", \n\"Web Technologies\" }; @Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); \nl = findViewById(R.id.list); \nArrayAdapter arr; \narr \n= new ArrayAdapter( \nthis, \nR.layout.support_simple_spinner_dropdown_item, \ntutorials); \nl.setAdapter(arr); \n} \n} Output",
"input": "",
"output": "oid Device is in Dock State?A docking station is a device that is competent in communicating with the Android kernel to fire docking-related events and revise the docking file state. A docking station can make the system and apps do anything that is programmed. One example is showing a different layout on the docked state. It may also open a music player app, play music automatically on desk mode if it is programmed as such, open a map/navigation app in car mode, etc. Dock Mode is different on different phones, but it often turns your phone into a desk clock, photo slideshow viewer, or music player. You can also set it as a speakerphone when you receive calls. The dock is built into self-amplified speakers or music boxes, or it is a stand-alone unit that connects via USB to a computer, charger, or home theater equipment. Some docks use USB for charging and Bluetooth for playing music. This mode is a feature that can be detected on some phones, including many of the Samsung phones, but is not a feature detect on every phone or every version of a phone. For example, Samsung Galaxy S2, S3, and S4 have a dock mode, but the S5 does not. Please check your phone features to make sure your phone is equipped with dock mode. So in this article let\u2019s discuss how to check if the Android device is in dock state or not or anything else. Note that we are going toimplement this project using theKotlinlanguage.\nSteps to Check if the Android Device is in Dock State\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Working with the activity_main.xml file\nGo to the activity_main.xml file, which represents the UI of the application. Create a Button, which on click provides the docking state of the device. Below is the code for theactivity_main.xml file.XML \n \n(R.id.btnCheck) \nbtn.setOnClickListener { // The dock-state details are included as an extra in a sticky broadcast of \n// the ACTION_DOCK_EVENT action. Because it's sticky, you can simply call \n// registerReceiver(), passing in null as the broadcast receiver. \nval dockStatus: Intent? = IntentFilter(Intent.ACTION_DOCK_EVENT) \n.let { ifilter -> \napplicationContext.registerReceiver(null, ifilter) \n} // dockState is an Integer value received when intent is passed \nval dockState: Int = dockStatus?.getIntExtra(EXTRA_DOCK_STATE, -1) ?: -1// isDocked is a Boolean value which if true indicates the device is in dock \n// state and vice-versa \nval isDocked: Boolean = dockState != Intent.EXTRA_DOCK_STATE_UNDOCKED // Finally depending upon the isDocked value display the Toasts \nif (isDocked) { \nToast.makeText(applicationContext, \"Docked\", Toast.LENGTH_SHORT).show() \n} else { \nToast.makeText(applicationContext, \"Not Docked\", Toast.LENGTH_SHORT).show() \n} \n} \n} \n}Output\nDepending upon the state, the application shows Toast messages, \u201cDocked\u201d when the device is docked, or \u201cNot Docked\u201d otherwise. The output is not available but this is the standard version of extracting the dock state in Android. Note that Android devices can be docked into several kinds of docks. These include car or home docks and digital versus analog docks. The dock-state is typically closely linked to the charging state as many docks provide power to docked devices."
},
{
"instruction": "oid Device is in Dock State?A docking station is a device that is competent in communicating with the Android kernel to fire docking-related events and revise the docking file state. A docking station can make the system and apps do anything that is programmed. One example is showing a different layout on the docked state. It may also open a music player app, play music automatically on desk mode if it is programmed as such, open a map/navigation app in car mode, etc. Dock Mode is different on different phones, but it often turns your phone into a desk clock, photo slideshow viewer, or music player. You can also set it as a speakerphone when you receive calls. The dock is built into self-amplified speakers or music boxes, or it is a stand-alone unit that connects via USB to a computer, charger, or home theater equipment. Some docks use USB for charging and Bluetooth for playing music. This mode is a feature that can be detected on some phones, including many of the Samsung phones, but is not a feature detect on every phone or every version of a phone. For example, Samsung Galaxy S2, S3, and S4 have a dock mode, but the S5 does not. Please check your phone features to make sure your phone is equipped with dock mode. So in this article let\u2019s discuss how to check if the Android device is in dock state or not or anything else. Note that we are going toimplement this project using theKotlinlanguage.\nSteps to Check if the Android Device is in Dock State\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Working with the activity_main.xml file\nGo to the activity_main.xml file, which represents the UI of the application. Create a Button, which on click provides the docking state of the device. Below is the code for theactivity_main.xml file.XML \n \n(R.id.btnCheck) \nbtn.setOnClickListener { // The dock-state details are included as an extra in a sticky broadcast of \n// the ACTION_DOCK_EVENT action. Because it's sticky, you can simply call \n// registerReceiver(), passing in null as the broadcast receiver. \nval dockStatus: Intent? = IntentFilter(Intent.ACTION_DOCK_EVENT) \n.let { ifilter -> \napplicationContext.registerReceiver(null, ifilter) \n} // dockState is an Integer value received when intent is passed \nval dockState: Int = dockStatus?.getIntExtra(EXTRA_DOCK_STATE, -1) ?: -1// isDocked is a Boolean value which if true indicates the device is in dock \n// state and vice-versa \nval isDocked: Boolean = dockState != Intent.EXTRA_DOCK_STATE_UNDOCKED // Finally depending upon the isDocked value display the Toasts \nif (isDocked) { \nToast.makeText(applicationContext, \"Docked\", Toast.LENGTH_SHORT).show() \n} else { \nToast.makeText(applicationContext, \"Not Docked\", Toast.LENGTH_SHORT).show() \n} \n} \n} \n}Output\nDepending upon the state, the application shows Toast messages, \u201cDocked\u201d when the device is docked, or \u201cNot Docked\u201d otherwise. The output is not available but this is the standard version of extracting the dock state in Android. Note that Android devices can be docked into several kinds of docks. These include car or home docks and digital versus analog docks. The dock-state is typically closely linked to the charging state as many docks provide power to docked devices.",
"input": "",
"output": "ader Library in Android Apps?COIL is an acronym for Coroutine Image Loader. COIL is one of the famous image loading libraries from URLs in Android. It is a modern library for loading images from the server. This library is used to load images from servers, assets folder as well as from the drawable folder in Android project. The important feature of this library is that it is fast, lightweight, and easy to use. In this article, we will see How to Use this Image Loader Library in Android Apps.\nWhy We Should use COIL for Loading Images?\nCOIL Image loading library is provided by Kotlin Coroutines which is used for loading images in Android. This library is specially designed for loading images in Kotlin. It is modern, easy to use, lightweight, and fast for loading images from the server. This is the new library and provides new optimization for loading images from the server very efficiently. As Kotlin is now been officially announced as the preferred language for Android development, that\u2019s why for loading images we should prefer using COIL for loading images in Android.\nWhat are the Advantages of using COIL over Picasso, Glide, and UIL?Google has officially announced Kotlin as a preferred language for Android development and COIL is the library that is better optimized with Kotlin. So the optimization of this library with Kotlin makes it easier to load images from the server.\nCOIL loads images very faster with the number of optimizations which includes memory, disk caching, reusing of bitmaps, and down spacing the image in memory which makes it faster in comparison with other image loading libraries.\nCOIL adds ~2000 methods to your APK which are very less in number in comparison with Picasso, Glide, and UIL. This makes this library very lightweight and easy to use.\nCOIL is the first image loading library which is completely introduced in Kotlin and it uses some modern libraries of Android such as Okio, OkHttp, and AndroidX lifecycles.Step by Step Implementation of COIL Image Loading Library\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Add dependency of Coil Image Loading library in build.gradle file\nNavigate to gradle scripts and then to build.gradle(Module) level. Add below line in build.gradle file in the dependencies section.implementation(\u201cio.coil-kt:coil:1.1.0\u201d)After adding dependency click on the \u201csync now\u201d option on the top right corner to sync the project.\nStep 3: Adding internet permission in the AndroidManifest.xml file\nNavigate to the app > Manifest to open the Manifest file. In the manifest file, we are adding internet permission to load images from the internet. Add the following lines in your manifest file.\n \n(R.id.imageView) // below line is for loading \n// image url inside imageview. \nimg.load(imgurl) { \n// placeholder image is the image used \n// when our image url fails to load. \nplaceholder(R.drawable.ic_launcher_background) \n} \n} \n}Output:"
},
{
"instruction": "ader Library in Android Apps?COIL is an acronym for Coroutine Image Loader. COIL is one of the famous image loading libraries from URLs in Android. It is a modern library for loading images from the server. This library is used to load images from servers, assets folder as well as from the drawable folder in Android project. The important feature of this library is that it is fast, lightweight, and easy to use. In this article, we will see How to Use this Image Loader Library in Android Apps.\nWhy We Should use COIL for Loading Images?\nCOIL Image loading library is provided by Kotlin Coroutines which is used for loading images in Android. This library is specially designed for loading images in Kotlin. It is modern, easy to use, lightweight, and fast for loading images from the server. This is the new library and provides new optimization for loading images from the server very efficiently. As Kotlin is now been officially announced as the preferred language for Android development, that\u2019s why for loading images we should prefer using COIL for loading images in Android.\nWhat are the Advantages of using COIL over Picasso, Glide, and UIL?Google has officially announced Kotlin as a preferred language for Android development and COIL is the library that is better optimized with Kotlin. So the optimization of this library with Kotlin makes it easier to load images from the server.\nCOIL loads images very faster with the number of optimizations which includes memory, disk caching, reusing of bitmaps, and down spacing the image in memory which makes it faster in comparison with other image loading libraries.\nCOIL adds ~2000 methods to your APK which are very less in number in comparison with Picasso, Glide, and UIL. This makes this library very lightweight and easy to use.\nCOIL is the first image loading library which is completely introduced in Kotlin and it uses some modern libraries of Android such as Okio, OkHttp, and AndroidX lifecycles.Step by Step Implementation of COIL Image Loading Library\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Add dependency of Coil Image Loading library in build.gradle file\nNavigate to gradle scripts and then to build.gradle(Module) level. Add below line in build.gradle file in the dependencies section.implementation(\u201cio.coil-kt:coil:1.1.0\u201d)After adding dependency click on the \u201csync now\u201d option on the top right corner to sync the project.\nStep 3: Adding internet permission in the AndroidManifest.xml file\nNavigate to the app > Manifest to open the Manifest file. In the manifest file, we are adding internet permission to load images from the internet. Add the following lines in your manifest file.\n \n(R.id.imageView) // below line is for loading \n// image url inside imageview. \nimg.load(imgurl) { \n// placeholder image is the image used \n// when our image url fails to load. \nplaceholder(R.drawable.ic_launcher_background) \n} \n} \n}Output:",
"input": "",
"output": " AndroidWe all have come across apps that have a Bottom Navigation Bar. Some popular examples include Instagram, WhatsApp, etc. In this article, let\u2019s learn how to implement such a functional Bottom Navigation Bar in the Android app. Below is the preview of a sample Bottom Navigation Bar:Why do we need a Bottom Navigation Bar?It allows the user to switch to different activities/fragments easily.\nIt makes the user aware of the different screens available in the app.\nThe user is able to check which screen are they on at the moment.The following is an anatomy diagram for the Bottom Navigation Bar:Steps for Creating Bottom Navigation Bar\nStep 1: Create a new Android Studio project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio.\nStep 2: Adding the dependency to the build.gradle(:app) file\nWe will be using Android\u2019s Material Design Library so we need to import it in the build.gradle(:app) file. Here\u2019s the dependency we need to add:implementation \u2018com.google.android.material:material:1.2.0\u2019Step 3: Working with activity_main.xml file\nFor this example, create a basic app with a FrameLayout and a Bottom Navigation Bar. The FrameLayout will contain Fragments which will change as the user click on the items in the Bottom Navigation Bar. This is how the activity_main.xml looks like:XML \nStep 4: Creating a menu for the Bottom Navigation Bar\nThe Navigation Bar needs to have some items which will create using Menu. To create a Menu, first, create a Menu Directory by clicking on the app -> res(right-click) -> New -> Android Resource Directory and select Menu in the Resource Type.To create a Menu Resource File , click on the app -> res -> menu(right-click) -> New -> Menu Resource File and name it bottom_nav_menu.Now the user can create as many items as he wants in the bottom_nav_menu.xml file. The user also needs to create an icon for each of these items. To create an icon, click on the app -> res -> drawable(right-click) -> New -> Image Asset.In the window that opens, the user can name the icon whatever he wants but it should not comprise any uppercase letter. The user can select the icon he wants by searching it and when the user is done, click Next-> Finish.Now add these items in the bottom_nav_menu.xml. This is how the bottom_nav_menu.xml file looks like after adding the items:XML \n\n\n\n\n Step 5: Changing the Action Bar style\nSince we are using Google\u2019s Material Design Library, we need to change the action bar\u2019s style to use the same library otherwise the Bottom Navigation Bar will be black and its items will be invisible. To change it, navigate to styles.xml by clicking on the app -> res -> values -> styles.xml and change the style opening tag as:Step 6: Creating Fragments to display\nNow that we have our Bottom Navigation Bar, we would want it to be functional by taking us to a different fragment/activity when an item is clicked. In this example, create a fragment for each item and navigate to them whenever a corresponding item is clicked. Since we created three items in the Bottom Navigation Bar, we will be creating three Fragments. To create a Fragment, click on the app(right-click) -> New -> Fragment -> Fragment (Blank). Name the fragment as FirstFragment and the corresponding XML file as fragment_first. To keep things simple, all three of the fragments will just contain a TextView. However, we can tweak this as we want it to be in the app. This is how the fragment_first.xml looks like after adding a TextView:XML \nStep 4: Creating a menu for the Bottom Navigation Bar\nThe Navigation Bar needs to have some items which will create using Menu. To create a Menu, first, create a Menu Directory by clicking on the app -> res(right-click) -> New -> Android Resource Directory and select Menu in the Resource Type.To create a Menu Resource File , click on the app -> res -> menu(right-click) -> New -> Menu Resource File and name it bottom_nav_menu.Now the user can create as many items as he wants in the bottom_nav_menu.xml file. The user also needs to create an icon for each of these items. To create an icon, click on the app -> res -> drawable(right-click) -> New -> Image Asset.In the window that opens, the user can name the icon whatever he wants but it should not comprise any uppercase letter. The user can select the icon he wants by searching it and when the user is done, click Next-> Finish.Now add these items in the bottom_nav_menu.xml. This is how the bottom_nav_menu.xml file looks like after adding the items:XML \n\n\n\n\n Step 5: Changing the Action Bar style\nSince we are using Google\u2019s Material Design Library, we need to change the action bar\u2019s style to use the same library otherwise the Bottom Navigation Bar will be black and its items will be invisible. To change it, navigate to styles.xml by clicking on the app -> res -> values -> styles.xml and change the style opening tag as:Step 6: Creating Fragments to display\nNow that we have our Bottom Navigation Bar, we would want it to be functional by taking us to a different fragment/activity when an item is clicked. In this example, create a fragment for each item and navigate to them whenever a corresponding item is clicked. Since we created three items in the Bottom Navigation Bar, we will be creating three Fragments. To create a Fragment, click on the app(right-click) -> New -> Fragment -> Fragment (Blank). Name the fragment as FirstFragment and the corresponding XML file as fragment_first. To keep things simple, all three of the fragments will just contain a TextView. However, we can tweak this as we want it to be in the app. This is how the fragment_first.xml looks like after adding a TextView:XML \n extends Activity {\n ........\n ........\n private globarVar;\n ........\n @Override\n public void onCreate(Bundle savedInstanceState) {\n .......\n final GlobalExampleClass globalExampleVariable = (GlobalExampleClass) getApplicationContext();\n \n // In this activity set name and email and can reuse in other activities\n globalExampleVariable.setName(\"getApplicationContext example\");\n globalExampleVariable.setEmail(\"xxxxxx@gmail.com\");\n \n .......\n}\n \n// Activity 2 \npublic class extends Activity {\n ........\n ........\n private globarVar;\n .......\n @Override\n public void onCreate(Bundle savedInstanceState) {\n .......\n final GlobalExampleClass globalExampleVariable = (GlobalExampleClass) getApplicationContext();\n \n // As in activity1, name and email is set, we can retrieve it here\n final String globalName = globalExampleVariable.getName();\n final String globalEmail = globalExampleVariable.getEmail();\n \n .......\n}\nSo, whenever the variable scope is required throughout the application, we can get it by means of getApplicationContext(). Following is a list of functionalities of Application Context.\nList of functionalities of Application Context:Load Resource Values\nStart a Service\nBind to a Service\nSend a Broadcast\nRegister BroadcastReceiverActivity Context\nIt is the activity Context meaning each and every screen got an activity. For example, EnquiryActivity refers to EnquiryActivity only and AddActivity refers to AddActivity only. It is tied to the life cycle of activity. It is used for the current Context. The method of invoking the Activity Context is getContext().\nSome use cases of Activity Context are:The user is creating an object whose lifecycle is attached to an activity.\nWhenever inside an activity for UI related kind of operations like toast, dialogue, etc.,getContext():\nIt returns the Context which is linked to the Activity from which it is called. This is useful when we want to call the Context from only the current running activity.\nExample:Java @Override\npublic void onItemClick(AdapterView parent, View view, int pos, long id) { \n// view.getContext() refers to the current activity view \n// Here it is used to start the activity \nIntent intent = new Intent(view.getContext(), ::class.java); \nintent.putExtra(pid, ID); \nview.getContext().startActivity(intent); \n}Kotlin fun onItemClick(parent: AdapterView<*>?, view: View, pos: Int, id: Long) { \n// view.getContext() refers to the current activity view \n// Here it is used to start the activity \nval intent = Intent(view.context, ::class.java) \nintent.putExtra(pid, ID) \nview.context.startActivity(intent) \n}List of Functionalities of Activity Context:Load Resource Values\nLayout Inflation\nStart an Activity\nShow a Dialog\nStart a Service\nBind to a Service\nSend a Broadcast\nRegister BroadcastReceiverFrom the functionalities of both Application and Activity, we can see that the difference is that the Application Context is not related to UI. It should be used only to start a service or load resource values etc. Apart from getApplicationContext() and getContext(), getBaseContext() or this are the different terminologies used throughout the app development. Let us see with an example\ngetBaseContext():\nThe base Context is set by the constructor or setBaseContext().This method is only valid if we have a ContextWrapper. Android provides a ContextWrapper class that is created around an existing Context using:\nContextWrapper wrapper = new ContextWrapper(context);\nThe benefit of using a ContextWrapper is that it lets you \u201cmodify behavior without changing the original Context\u201d.\nSyntax:\npublic (Context ctx) {\n // if the context is instanceof ContextWrapper\n while (ctx instanceof ContextWrapper) {\n // use getBaseContext()\n final Context baseContext = ((ContextWrapper)context).getBaseContext();\n if (baseContext == null) {\n break;\n }\n // And then we can assign to context and reuse that\n ctx = baseContext;\n }\n}\nthis:\n\u201cthis\u201d argument is of a type \u201cContext\u201d. To explain this Context let\u2019s take an example to show a Toast Message using \u201cthis\u201d.\nExample:Java import android.os.Bundle; \nimport android.widget.Toast; \nimport androidx.appcompat.app.AppCompatActivity; // Show a simple toast message, that can be done after doing some activities \n// Toast.makeText(this, \"Action got completed\", Toast.LENGTH_SHORT).show(); public class ExampleActivity extends AppCompatActivity { \n@Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main_example); // Displaying Toast with Hello Javatpoint message \nToast.makeText(this,\"Action done\",Toast.LENGTH_SHORT).show(); \n} \n}Kotlin import android.os.Bundle \nimport android.widget.Toast \nimport androidx.appcompat.app.AppCompatActivity // Show a simple toast message, that can be done after doing some activities \n// Toast.makeText(this, \"Action got completed\", Toast.LENGTH_SHORT).show(); class ExampleActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main_example) // Displaying Toast with Hello Javatpoint message \nToast.makeText(this, \"Action done\", Toast.LENGTH_SHORT).show() \n} \n}Another example to start the activity using \u201cthis\u201d:Java import androidx.appcompat.app.AppCompatActivity; \nimport android.content.Intent; \nimport android.os.Bundle; \nimport android.view.View; \nimport android.widget.EditText; public class FirstActivity extends AppCompatActivity { public static final String newMessage = \"Your message to go for next screen\"; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_first); \n} // There must be some button and on click of \n// that below method can be invoked \npublic void sendMessageToNextScreen(View view) { \n// Here it is used with \"this\" \nIntent intent = new Intent(this, SecondActivity.class); \nEditText editText = (EditText) findViewById(R.id.editText); \nString message = editText.getText().toString(); \nintent.putExtra(newMessage, message); // Start the SecondActivity \nstartActivity(intent); \n} \n}Kotlin import android.content.Intent \nimport android.os.Bundle \nimport android.view.View \nimport android.widget.EditText \nimport androidx.appcompat.app.AppCompatActivity class FirstActivity : AppCompatActivity() { private var newMessage = \"Your message to go for next screen\"override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_first) \n} // There must be some button and on click of \n// that below method can be invoked \nfun sendMessageToNextScreen(view: View?) { \n// Here it is used with \"this\" \nval intent = Intent(this, SecondActivity::class.java) \nval editText: EditText = findViewById(R.id.editText) \nval message = editText.text.toString() \nintent.putExtra(newMessage, message) // Start the SecondActivity \nstartActivity(intent) \n} \n}"
},
{
"instruction": "id?Android Applications are popular for a long time and it is evolving to a greater level as users\u2019 expectations are that they need to view the data that they want in an easier smoother view. Hence, the android developers must know the important terminologies before developing the app. In Android Programming we generally come across the word Context. So what exactly is this Context and why is it so important? To answer this question let\u2019s first see what the literal meaning of Context is:The Circumstances that form the setting for an Event, Statement, or Idea, and in terms of which it can be fully understood.Looking at this definition we come across two things:The Context tells us about the surrounding information.\nIt is very important to understand the environment which we want to understand.Similarly when we talk about Android Programming Context can be understood as something which gives us the Context of the current state of our application. We can break the Context and its use into three major points:It allows us to access resources.\nIt allows us to interact with other Android components by sending messages.\nIt gives you information about your app environment.The code has been given in both Java and Kotlin Programming Language for Android.\nUnderstanding Context by a Real World Example\nLet\u2019s a person visit a hotel. He needs breakfast, lunch, and dinner at a suitable time. Except for these things there are also many other things, he wants to do during his time of stay. So how does he get these things? He will ask the room-service person to bring these things for him. Right? So here the room-service person is the Context considering you are the single activity and the hotel to be your app, finally, the breakfast, lunch & dinner have to be the resources.\nHow Does this Work?\n1. It is the Context of the current/active state of the application.\nUsually, the app got multiple screens like display/inquiry/add/delete screens(A general requirement of a basic app). So when the user is searching for something, the Context is an inquiry screen in this case.\n2. It is used to get information about the activity and application.\nThe inquiry screen\u2019s Context specifies that the user is in inquiry activity, and he/she can submit queries related to the app\n3. It is used to get access to resources, databases, shared preferences, etc.\nVia Rest services, API calls can be consumed in android apps. Rest Services usually hold database data and provide the output in JSON format to the android app. The Context for the respective screen helps to get hold of database data and the shared data across screens\n4. Both the Activity and Application classes extend the Context class.\nIn android, Context is the main important concept and the wrong usage of it leads to memory leakage. Activity refers to an individual screen and Application refers to the whole app and both extend the Context class.\nTypes of Context in Android\nThere are mainly two types of Context that are available in Android.Application Context and\nActivity ContextThe Overall view of the App hierarchy looks like the following:It can be seen in the above image that in \u201cSample Application\u201d, the nearest Context is Application Context. In \u201cActivity1\u201d and \u201cActivity2\u201d, both Activity Context (Here it is Activity1 Context for Activity1 and Activity2 Context for Activity2) and Application Context.The nearest Context to both is their Activity Context only.\nApplication Context\nThis Context is tied to the Lifecycle of an Application. Mainly it is an instance that is a singleton and can be accessed via getApplicationContext(). Some use cases of Application Context are:If it is necessary to create a singleton object\nDuring the necessity of a library in an activitygetApplicationContext():\nIt is used to return the Context which is linked to the Application which holds all activities running inside it. When we call a method or a constructor, we often have to pass a Context and often we use \u201cthis\u201d to pass the activity Context or \u201cgetApplicationContext\u201d to pass the application Context. This method is generally used for the application level and can be used to refer to all the activities. For example, if we want to access a variable throughout the android app, one has to use it via getApplicationContext().\nExample:Java import android.app.Application; public class GlobalExampleClass extends Application { \nprivate String globalName; \nprivate String globalEmail; public String getName() { \nreturn globalName; \n} public void setName(String aName) { \nglobalName = aName; \n} public String getEmail() { \nreturn globalEmail; \n} public void setEmail(String aEmail) { \nglobalEmail = aEmail; \n} \n}Kotlin import android.app.Application class GlobalExampleClass : Application() { \nprivate var globalName: String? = null\nprivate var globalEmail: String? = nullfun getName(): String? { \nreturn globalName \n} fun setName(aName: String?) { \nglobalName = aName \n} fun getEmail(): String? { \nreturn globalEmail \n} fun setEmail(aEmail: String?) { \nglobalEmail = aEmail \n} \n}Inside the activity class, set the name and email of GlobalExampleClass, which can be accessed from another activity. Let us see via the below steps.\nSyntax:\n// Activity 1\npublic class extends Activity {\n ........\n ........\n private globarVar;\n ........\n @Override\n public void onCreate(Bundle savedInstanceState) {\n .......\n final GlobalExampleClass globalExampleVariable = (GlobalExampleClass) getApplicationContext();\n \n // In this activity set name and email and can reuse in other activities\n globalExampleVariable.setName(\"getApplicationContext example\");\n globalExampleVariable.setEmail(\"xxxxxx@gmail.com\");\n \n .......\n}\n \n// Activity 2 \npublic class extends Activity {\n ........\n ........\n private globarVar;\n .......\n @Override\n public void onCreate(Bundle savedInstanceState) {\n .......\n final GlobalExampleClass globalExampleVariable = (GlobalExampleClass) getApplicationContext();\n \n // As in activity1, name and email is set, we can retrieve it here\n final String globalName = globalExampleVariable.getName();\n final String globalEmail = globalExampleVariable.getEmail();\n \n .......\n}\nSo, whenever the variable scope is required throughout the application, we can get it by means of getApplicationContext(). Following is a list of functionalities of Application Context.\nList of functionalities of Application Context:Load Resource Values\nStart a Service\nBind to a Service\nSend a Broadcast\nRegister BroadcastReceiverActivity Context\nIt is the activity Context meaning each and every screen got an activity. For example, EnquiryActivity refers to EnquiryActivity only and AddActivity refers to AddActivity only. It is tied to the life cycle of activity. It is used for the current Context. The method of invoking the Activity Context is getContext().\nSome use cases of Activity Context are:The user is creating an object whose lifecycle is attached to an activity.\nWhenever inside an activity for UI related kind of operations like toast, dialogue, etc.,getContext():\nIt returns the Context which is linked to the Activity from which it is called. This is useful when we want to call the Context from only the current running activity.\nExample:Java @Override\npublic void onItemClick(AdapterView parent, View view, int pos, long id) { \n// view.getContext() refers to the current activity view \n// Here it is used to start the activity \nIntent intent = new Intent(view.getContext(), ::class.java); \nintent.putExtra(pid, ID); \nview.getContext().startActivity(intent); \n}Kotlin fun onItemClick(parent: AdapterView<*>?, view: View, pos: Int, id: Long) { \n// view.getContext() refers to the current activity view \n// Here it is used to start the activity \nval intent = Intent(view.context, ::class.java) \nintent.putExtra(pid, ID) \nview.context.startActivity(intent) \n}List of Functionalities of Activity Context:Load Resource Values\nLayout Inflation\nStart an Activity\nShow a Dialog\nStart a Service\nBind to a Service\nSend a Broadcast\nRegister BroadcastReceiverFrom the functionalities of both Application and Activity, we can see that the difference is that the Application Context is not related to UI. It should be used only to start a service or load resource values etc. Apart from getApplicationContext() and getContext(), getBaseContext() or this are the different terminologies used throughout the app development. Let us see with an example\ngetBaseContext():\nThe base Context is set by the constructor or setBaseContext().This method is only valid if we have a ContextWrapper. Android provides a ContextWrapper class that is created around an existing Context using:\nContextWrapper wrapper = new ContextWrapper(context);\nThe benefit of using a ContextWrapper is that it lets you \u201cmodify behavior without changing the original Context\u201d.\nSyntax:\npublic (Context ctx) {\n // if the context is instanceof ContextWrapper\n while (ctx instanceof ContextWrapper) {\n // use getBaseContext()\n final Context baseContext = ((ContextWrapper)context).getBaseContext();\n if (baseContext == null) {\n break;\n }\n // And then we can assign to context and reuse that\n ctx = baseContext;\n }\n}\nthis:\n\u201cthis\u201d argument is of a type \u201cContext\u201d. To explain this Context let\u2019s take an example to show a Toast Message using \u201cthis\u201d.\nExample:Java import android.os.Bundle; \nimport android.widget.Toast; \nimport androidx.appcompat.app.AppCompatActivity; // Show a simple toast message, that can be done after doing some activities \n// Toast.makeText(this, \"Action got completed\", Toast.LENGTH_SHORT).show(); public class ExampleActivity extends AppCompatActivity { \n@Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main_example); // Displaying Toast with Hello Javatpoint message \nToast.makeText(this,\"Action done\",Toast.LENGTH_SHORT).show(); \n} \n}Kotlin import android.os.Bundle \nimport android.widget.Toast \nimport androidx.appcompat.app.AppCompatActivity // Show a simple toast message, that can be done after doing some activities \n// Toast.makeText(this, \"Action got completed\", Toast.LENGTH_SHORT).show(); class ExampleActivity : AppCompatActivity() { \noverride fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main_example) // Displaying Toast with Hello Javatpoint message \nToast.makeText(this, \"Action done\", Toast.LENGTH_SHORT).show() \n} \n}Another example to start the activity using \u201cthis\u201d:Java import androidx.appcompat.app.AppCompatActivity; \nimport android.content.Intent; \nimport android.os.Bundle; \nimport android.view.View; \nimport android.widget.EditText; public class FirstActivity extends AppCompatActivity { public static final String newMessage = \"Your message to go for next screen\"; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_first); \n} // There must be some button and on click of \n// that below method can be invoked \npublic void sendMessageToNextScreen(View view) { \n// Here it is used with \"this\" \nIntent intent = new Intent(this, SecondActivity.class); \nEditText editText = (EditText) findViewById(R.id.editText); \nString message = editText.getText().toString(); \nintent.putExtra(newMessage, message); // Start the SecondActivity \nstartActivity(intent); \n} \n}Kotlin import android.content.Intent \nimport android.os.Bundle \nimport android.view.View \nimport android.widget.EditText \nimport androidx.appcompat.app.AppCompatActivity class FirstActivity : AppCompatActivity() { private var newMessage = \"Your message to go for next screen\"override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_first) \n} // There must be some button and on click of \n// that below method can be invoked \nfun sendMessageToNextScreen(view: View?) { \n// Here it is used with \"this\" \nval intent = Intent(this, SecondActivity::class.java) \nval editText: EditText = findViewById(R.id.editText) \nval message = editText.text.toString() \nintent.putExtra(newMessage, message) // Start the SecondActivity \nstartActivity(intent) \n} \n}",
"input": "",
"output": "lculator app using Android Studio?Pre-requisites:Android App Development Fundamentals for Beginners\nGuide to Install and Set up Android Studio\nAndroid | Starting with first app/android project\nAndroid | Running your first Android appCreate a simple calculator which can perform basic arithmetic operations like addition, subtraction, multiplication, or division depending upon the user input. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.https://media.geeksforgeeks.org/wp-content/uploads/20210629133649/build-a-simple-Calculator-app-using-Android-Studio.mp4\nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Working with the activity_main.xml file\nNavigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.XML \n\n\n \n \n MainActivity.java package org.geeksforgeeks.navedmalik.calendar; import android.support.annotation.NonNull; \nimport android.support.v7.app.AppCompatActivity; \nimport android.os.Bundle; \nimport android.widget.Button; \nimport android.widget.CalendarView; \nimport android.widget.TextView; public class MainActivity extends AppCompatActivity { // Define the variable of CalendarView type \n// and TextView type; \nCalendarView calendar; \nTextView date_view; \n@Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // By ID we can use each component \n// which id is assign in xml file \n// use findViewById() to get the \n// CalendarView and TextView \ncalendar = (CalendarView) \nfindViewById(R.id.calendar); \ndate_view = (TextView) \nfindViewById(R.id.date_view); // Add Listener in calendar \ncalendar \n.setOnDateChangeListener( \nnew CalendarView \n.OnDateChangeListener() { \n@Override// In this Listener have one method \n// and in this method we will \n// get the value of DAYS, MONTH, YEARS \npublic void onSelectedDayChange( \n@NonNull CalendarView view, \nint year, \nint month, \nint dayOfMonth) \n{ // Store the value of date with \n// format in String type Variable \n// Add 1 in month because month \n// index is start with 0 \nString Date \n= dayOfMonth + \"-\"\n+ (month + 1) + \"-\" + year; // set this date in TextView for Display \ndate_view.setText(Date); \n} \n}); \n} \n} Output:"
},
{
"instruction": "endar View appThis article shows how to create an android application for displaying the Calendar using CalendarView. It also provides the selection of the current date and displaying the date. The setOnDateChangeListener Interface is used which provide onSelectedDayChange method.onSelectedDayChange: In this method, we get the values of days, months, and years that are selected by the user.Below are the steps for creating the Android Application of the Calendar.Step 1: Create a new project and you will have a layout XML file and java file. Your screen will look like the image below.\nStep 2: Open your xml file and add CalendarView and TextView. And assign id to TextView and CalendarView. After completing this process, the xml file screen looks like given below.\nStep 3: Now, open up the activity java file and define the CalendarView and TextView type variable, and also use findViewById() to get the Calendarview and textview.\nStep 4: Now, add setOnDateChangeListener interface in object of CalendarView which provides setOnDateChangeListener method. In this method, we get the Dates(days, months, years) and set the dates in TextView for Display.\nStep 5: Now run the app and set the current date which will be shown on the top of the screen.Complete code of MainActivity.java or activity_main.xml of Calendar is given below.activity_main.xml \n \n \n MainActivity.java package org.geeksforgeeks.navedmalik.calendar; import android.support.annotation.NonNull; \nimport android.support.v7.app.AppCompatActivity; \nimport android.os.Bundle; \nimport android.widget.Button; \nimport android.widget.CalendarView; \nimport android.widget.TextView; public class MainActivity extends AppCompatActivity { // Define the variable of CalendarView type \n// and TextView type; \nCalendarView calendar; \nTextView date_view; \n@Override\nprotected void onCreate(Bundle savedInstanceState) \n{ \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // By ID we can use each component \n// which id is assign in xml file \n// use findViewById() to get the \n// CalendarView and TextView \ncalendar = (CalendarView) \nfindViewById(R.id.calendar); \ndate_view = (TextView) \nfindViewById(R.id.date_view); // Add Listener in calendar \ncalendar \n.setOnDateChangeListener( \nnew CalendarView \n.OnDateChangeListener() { \n@Override// In this Listener have one method \n// and in this method we will \n// get the value of DAYS, MONTH, YEARS \npublic void onSelectedDayChange( \n@NonNull CalendarView view, \nint year, \nint month, \nint dayOfMonth) \n{ // Store the value of date with \n// format in String type Variable \n// Add 1 in month because month \n// index is start with 0 \nString Date \n= dayOfMonth + \"-\"\n+ (month + 1) + \"-\" + year; // set this date in TextView for Display \ndate_view.setText(Date); \n} \n}); \n} \n} Output:",
"input": "",
"output": " KotlinIn Android Animations are the visuals that are added to make the user interface more interactive, clear and good looking.\nIn this article we will be discussing how to create a Slide Up/Down animation in Kotlin.XML Attributes\nDescriptionandroid:duration\nIt is used to specify the duration of animation android:fromYDelta\nIt is the change in Y coordinate to be applied at the start of the animationandroid:toYDelta\nIt is the change in Y coordinate to be applied at the end of the animationandroid:id\nSets unique id of the viewFirst step is to create a new Project in Android Studio. For this follow these steps:Click on File, then New and then New Project and give name whatever you like\nThen, select Kotlin language Support and click next button.\nSelect minimum SDK, whatever you need\nSelect Empty activity and then click finish.After that, we need to design our layout. For that we need to work with the XML file. Go to app > res > layout and paste the following code:\nModify activity_main.xml file \n Add anim folder\nIn this folder, we will be adding the XML files which will be used to produce the animations. For this to happen, go to app/res right click and then select, Android Resource Directory and name it as anim.\nAgain right click this anim folder and select Animation resource file and name it as slide_up. Similarly, also create slide_down.xml and paste the following code.\nslide_up.xml \n \n slide_down.xml \n \n Modify MainActivity.kt file\nOpen app/src/main/java/yourPackageName/MainActivity.kt and do the following changes: package com.geeksforgeeks.myfirstKotlinapp import androidx.appcompat.app.AppCompatActivity \nimport android.os.Bundle \nimport android.view.animation.AnimationUtils \nimport kotlinx.android.synthetic.main.activity_main.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) //setting buttons onClickListener \nslide_down.setOnClickListener { \n//adding our custom made animation xml file \nval animation = AnimationUtils.loadAnimation( \nthis, R.anim.fade_out) \n//appending animation to textView \ntextView.startAnimation(animation) \n} \nslide_up.setOnClickListener { \nval animation = AnimationUtils.loadAnimation( \nthis, R.anim.fade_in) \ntextView.startAnimation(animation) \n} \n} \n} AndroidManifest.xml file \n \n \n \n \n \n \n Run as emulator: https://media.geeksforgeeks.org/wp-content/uploads/20191124123100/slideUp.mp4"
},
{
"instruction": " KotlinIn Android Animations are the visuals that are added to make the user interface more interactive, clear and good looking.\nIn this article we will be discussing how to create a Slide Up/Down animation in Kotlin.XML Attributes\nDescriptionandroid:duration\nIt is used to specify the duration of animation android:fromYDelta\nIt is the change in Y coordinate to be applied at the start of the animationandroid:toYDelta\nIt is the change in Y coordinate to be applied at the end of the animationandroid:id\nSets unique id of the viewFirst step is to create a new Project in Android Studio. For this follow these steps:Click on File, then New and then New Project and give name whatever you like\nThen, select Kotlin language Support and click next button.\nSelect minimum SDK, whatever you need\nSelect Empty activity and then click finish.After that, we need to design our layout. For that we need to work with the XML file. Go to app > res > layout and paste the following code:\nModify activity_main.xml file \n Add anim folder\nIn this folder, we will be adding the XML files which will be used to produce the animations. For this to happen, go to app/res right click and then select, Android Resource Directory and name it as anim.\nAgain right click this anim folder and select Animation resource file and name it as slide_up. Similarly, also create slide_down.xml and paste the following code.\nslide_up.xml \n \n slide_down.xml \n \n Modify MainActivity.kt file\nOpen app/src/main/java/yourPackageName/MainActivity.kt and do the following changes: package com.geeksforgeeks.myfirstKotlinapp import androidx.appcompat.app.AppCompatActivity \nimport android.os.Bundle \nimport android.view.animation.AnimationUtils \nimport kotlinx.android.synthetic.main.activity_main.* class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) //setting buttons onClickListener \nslide_down.setOnClickListener { \n//adding our custom made animation xml file \nval animation = AnimationUtils.loadAnimation( \nthis, R.anim.fade_out) \n//appending animation to textView \ntextView.startAnimation(animation) \n} \nslide_up.setOnClickListener { \nval animation = AnimationUtils.loadAnimation( \nthis, R.anim.fade_in) \ntextView.startAnimation(animation) \n} \n} \n} AndroidManifest.xml file \n \n \n \n \n \n \n Run as emulator: https://media.geeksforgeeks.org/wp-content/uploads/20191124123100/slideUp.mp4",
"input": "",
"output": " That Every Android Developer Should KnowAndroid is an operating system which is built basically for Mobile phones. It is used for touchscreen mobile devices like smartphones and tablets. But nowadays these are utilized in Android Auto cars, TV, watches, camera, etc. Android has been one of the best-selling OS for smartphones. Android OS was developed by Android Inc. which Google bought in 2005. Today, Android remains to dominate on a global scale. It is an operating system that has a huge market for apps.Developing an Android application without Android libraries\u2019 magic is always a wearying job. Libraries help to lessen the time, effort, and money required for the creation of an Android app. Here are some of the best libraries that every developer should know.\n1. Dagger 2\nDagger 2 is one of the best Android libraries and it mainly relies on using Java annotation processors that include compiling time in order to calculate and identify dependencies. The main benefit of Dagger 2 over other dependency injection frameworks is that its strictly designed implementation means that it can be utilized in Android applications. But, there are still some factors to be made when using Dagger within Android applications. The basic dilemma of creating an Android application using Dagger is that several Android framework classes are instantiated by the OS itself, like Activity and Fragment, but Dagger works great if it can generate all the injected objects. Alternatively, the developers have to perform members\u2019 injection in a lifecycle method.\n2. Retrofit\nRetrofit is a type-safe REST client build by square for Android and Java which intends to make it simpler to expand RESTful web services. Retrofit uses OkHttp as the systems administration layer and is based on it. Retrofit naturally serializes the JSON reaction utilizing a POJO (PlainOldJavaObject) which must be characterized in cutting edge for the JSON Structure. To serialize JSON we require a converter to change over it into Gson first. Retrofit is much simpler than other libraries we don\u2019t have to parse our JSON it directly returns objects but there is one disadvantage also it doesn\u2019t provide support to load images from the server but we can use Picasso for the same.\n3. Picasso\nPicasso is an open-source and one of the widely used image downloaders libraries in Android. It is created and maintained by Square. It is one of the powerful image downloads and caching library in Android. Picasso simplifies the process of loading images from external URLs and displays on the application. For example, downloading an image from the server is one of the most common tasks in any application. And it needs quite a larger amount of code to achieve this via android networking APIs. By using Picasso, one can achieve this with a few lines of code.\n4. Glide\nGlide is similar to Picasso and can load and display images from many sources, while also taking care of caching and keeping a low memory impact when doing image manipulations. Official Google apps are also using Glide. Glide is an Image Loader Library in Android developed by bumptech and is a library that is backed by Google. It has been utilized in many Google open source projects including Google I/O 2014 official application. It renders animated GIF support and handles image loading/caching.\n5. Zxing\nZXing stands for \u201czebra crossing\u201d. It is a barcode image processing library implemented in Java, with ports to other languages. It has support for the 1D product, 1D industrial, and 2D barcodes. Google uses ZXing by web search to obtain millions of barcodes on the web indexable. It also creates the foundation of Android\u2019s Barcode Scanner app and is combined into Google Product and Book Search.\n6. CAMView\nCAMView is an android camera easy access library and installed QR scanner, based on ZXing. It is an android library with simple yet compelling components for using the device camera in the apps. The library comprises a set of components (views), ready to be set to the layout files in order to provide developer instant access to the following features:Immediately display the live preview video feed from the device camera\nScan barcodes using built-in ZXing decoding engine\nPerform your own camera live data processingCAMView takes and hides all the messy jobs and mangles for handling the low-level methods, like camera initialization, configuration, streaming, orientation changes, device and cameras compatibility, threading, etc. Just set the proper view component to the layout and the app is camera-ready.\n7. Stetho\nStetho is a sophisticated debug bridge for Android applications. When enabled, developers have a path to the Chrome Developer Tools feature natively part of the Chrome desktop browser. Developers can also prefer to allow the optional dumpapp tool which allows a powerful command-line interface to application internals. Without limiting its functionality to just network inspection, JavaScript console, database inspection, etc.\n8. ButterKnife\nButterKnife is one of the best android libraries that bind android views and callbacks to fields and methods. But unfortunately, this tool is now deprecated. Developers are switching to View Binding. View binding is a feature that enables you to more efficiently write code that interacts with views. Once view binding is allowed in a module, it forms a binding class for each XML layout file available in that module. An example of a binding class contains direct references to all views that have an ID in the corresponding layout. In most cases, view binding replaces findViewById."
},
{
"instruction": " That Every Android Developer Should KnowAndroid is an operating system which is built basically for Mobile phones. It is used for touchscreen mobile devices like smartphones and tablets. But nowadays these are utilized in Android Auto cars, TV, watches, camera, etc. Android has been one of the best-selling OS for smartphones. Android OS was developed by Android Inc. which Google bought in 2005. Today, Android remains to dominate on a global scale. It is an operating system that has a huge market for apps.Developing an Android application without Android libraries\u2019 magic is always a wearying job. Libraries help to lessen the time, effort, and money required for the creation of an Android app. Here are some of the best libraries that every developer should know.\n1. Dagger 2\nDagger 2 is one of the best Android libraries and it mainly relies on using Java annotation processors that include compiling time in order to calculate and identify dependencies. The main benefit of Dagger 2 over other dependency injection frameworks is that its strictly designed implementation means that it can be utilized in Android applications. But, there are still some factors to be made when using Dagger within Android applications. The basic dilemma of creating an Android application using Dagger is that several Android framework classes are instantiated by the OS itself, like Activity and Fragment, but Dagger works great if it can generate all the injected objects. Alternatively, the developers have to perform members\u2019 injection in a lifecycle method.\n2. Retrofit\nRetrofit is a type-safe REST client build by square for Android and Java which intends to make it simpler to expand RESTful web services. Retrofit uses OkHttp as the systems administration layer and is based on it. Retrofit naturally serializes the JSON reaction utilizing a POJO (PlainOldJavaObject) which must be characterized in cutting edge for the JSON Structure. To serialize JSON we require a converter to change over it into Gson first. Retrofit is much simpler than other libraries we don\u2019t have to parse our JSON it directly returns objects but there is one disadvantage also it doesn\u2019t provide support to load images from the server but we can use Picasso for the same.\n3. Picasso\nPicasso is an open-source and one of the widely used image downloaders libraries in Android. It is created and maintained by Square. It is one of the powerful image downloads and caching library in Android. Picasso simplifies the process of loading images from external URLs and displays on the application. For example, downloading an image from the server is one of the most common tasks in any application. And it needs quite a larger amount of code to achieve this via android networking APIs. By using Picasso, one can achieve this with a few lines of code.\n4. Glide\nGlide is similar to Picasso and can load and display images from many sources, while also taking care of caching and keeping a low memory impact when doing image manipulations. Official Google apps are also using Glide. Glide is an Image Loader Library in Android developed by bumptech and is a library that is backed by Google. It has been utilized in many Google open source projects including Google I/O 2014 official application. It renders animated GIF support and handles image loading/caching.\n5. Zxing\nZXing stands for \u201czebra crossing\u201d. It is a barcode image processing library implemented in Java, with ports to other languages. It has support for the 1D product, 1D industrial, and 2D barcodes. Google uses ZXing by web search to obtain millions of barcodes on the web indexable. It also creates the foundation of Android\u2019s Barcode Scanner app and is combined into Google Product and Book Search.\n6. CAMView\nCAMView is an android camera easy access library and installed QR scanner, based on ZXing. It is an android library with simple yet compelling components for using the device camera in the apps. The library comprises a set of components (views), ready to be set to the layout files in order to provide developer instant access to the following features:Immediately display the live preview video feed from the device camera\nScan barcodes using built-in ZXing decoding engine\nPerform your own camera live data processingCAMView takes and hides all the messy jobs and mangles for handling the low-level methods, like camera initialization, configuration, streaming, orientation changes, device and cameras compatibility, threading, etc. Just set the proper view component to the layout and the app is camera-ready.\n7. Stetho\nStetho is a sophisticated debug bridge for Android applications. When enabled, developers have a path to the Chrome Developer Tools feature natively part of the Chrome desktop browser. Developers can also prefer to allow the optional dumpapp tool which allows a powerful command-line interface to application internals. Without limiting its functionality to just network inspection, JavaScript console, database inspection, etc.\n8. ButterKnife\nButterKnife is one of the best android libraries that bind android views and callbacks to fields and methods. But unfortunately, this tool is now deprecated. Developers are switching to View Binding. View binding is a feature that enables you to more efficiently write code that interacts with views. Once view binding is allowed in a module, it forms a binding class for each XML layout file available in that module. An example of a binding class contains direct references to all views that have an ID in the corresponding layout. In most cases, view binding replaces findViewById.",
"input": "",
"output": "ashlight/TorchLight Android App?All the beginners who are into the android development world should build a simple android application that can turn on/off the flashlight or torchlight by clicking a Button. So at the end of this article, one will be able to build their own android flashlight application with a simple layout. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language.Steps for Building a Simple Flashlight/TorchLight Android App\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Working with the activity_main.xmlThis layout contains a simple TextView, View (as divider), and one ToggleButton to toggle the Flashlight unit.\nPlease refer to How to add Toggle Button in an Android Application, to implement, and to see how the toggle button works.\nInvoke the following code in the activity_main.xml file or one can design custom widgets.XML \n(Context.CAMERA_SERVICE) as CameraManager// Exception is handled, because to check whether\n// the camera resource is being used by another\n// service or not.\ntry {\n// O means back camera unit,\n// 1 means front camera unit\ngetCameraID = cameraManager!!.cameraIdList[0]\n} catch (e: CameraAccessException) {\ne.printStackTrace()\n}\n}// RequiresApi is set because, the devices which are\n// below API level 10 don't have the flash unit with\n// camera.\n@RequiresApi(api = Build.VERSION_CODES.M)\nfun toggleFlashLight(view: View?) {\nif (toggleFlashLightOnOff!!.isChecked) {\n// Exception is handled, because to check\n// whether the camera resource is being used by\n// another service or not.\ntry {\n// true sets the torch in ON mode\ncameraManager!!.setTorchMode(getCameraID!!, true)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@MainActivity, \"Flashlight is turned ON\", Toast.LENGTH_SHORT)\n.show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n} else {\n// Exception is handled, because to check\n// whether the camera resource is being used by\n// another service or not.\ntry {\n// true sets the torch in OFF mode\ncameraManager!!.setTorchMode(getCameraID!!, false)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@MainActivity, \"Flashlight is turned OFF\", Toast.LENGTH_SHORT)\n.show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n}\n}// when you click on button and torch open and\n// you do not close the tourch again this code\n// will off the tourch automatically\n@RequiresApi(api = Build.VERSION_CODES.M)\noverride fun finish() {\nsuper.finish()\ntry {\n// true sets the torch in OFF mode\ncameraManager!!.setTorchMode(getCameraID!!, false)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@SlaphScreen, \"Flashlight is turned OFF\", Toast.LENGTH_SHORT).show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n}\n}\n// This code is added by Ujjwal Kumar BhardwajRead about the printStackTrace() function here: Throwable printStackTrace() method in Java with Examples.\nAfter handling the ToggleButton one needs to test the application under a physical android device. Because if you run the application in the emulator which comes with android studio, the app is going to crash as soon as ToggleButton is clicked, because the emulator device wouldn\u2019t come with the camera flash unit.\nThis method of accessing the camera hardware doesn\u2019t require special permission from the user to access the camera unit. Because in this we are accessing the flash unit through only camera ID (whether it\u2019s a front camera or back camera).Output:https://media.geeksforgeeks.org/wp-content/uploads/20200921184957/GFG_frame_nexus_5.mp4"
},
{
"instruction": "ashlight/TorchLight Android App?All the beginners who are into the android development world should build a simple android application that can turn on/off the flashlight or torchlight by clicking a Button. So at the end of this article, one will be able to build their own android flashlight application with a simple layout. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language.Steps for Building a Simple Flashlight/TorchLight Android App\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Working with the activity_main.xmlThis layout contains a simple TextView, View (as divider), and one ToggleButton to toggle the Flashlight unit.\nPlease refer to How to add Toggle Button in an Android Application, to implement, and to see how the toggle button works.\nInvoke the following code in the activity_main.xml file or one can design custom widgets.XML \n(Context.CAMERA_SERVICE) as CameraManager// Exception is handled, because to check whether\n// the camera resource is being used by another\n// service or not.\ntry {\n// O means back camera unit,\n// 1 means front camera unit\ngetCameraID = cameraManager!!.cameraIdList[0]\n} catch (e: CameraAccessException) {\ne.printStackTrace()\n}\n}// RequiresApi is set because, the devices which are\n// below API level 10 don't have the flash unit with\n// camera.\n@RequiresApi(api = Build.VERSION_CODES.M)\nfun toggleFlashLight(view: View?) {\nif (toggleFlashLightOnOff!!.isChecked) {\n// Exception is handled, because to check\n// whether the camera resource is being used by\n// another service or not.\ntry {\n// true sets the torch in ON mode\ncameraManager!!.setTorchMode(getCameraID!!, true)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@MainActivity, \"Flashlight is turned ON\", Toast.LENGTH_SHORT)\n.show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n} else {\n// Exception is handled, because to check\n// whether the camera resource is being used by\n// another service or not.\ntry {\n// true sets the torch in OFF mode\ncameraManager!!.setTorchMode(getCameraID!!, false)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@MainActivity, \"Flashlight is turned OFF\", Toast.LENGTH_SHORT)\n.show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n}\n}// when you click on button and torch open and\n// you do not close the tourch again this code\n// will off the tourch automatically\n@RequiresApi(api = Build.VERSION_CODES.M)\noverride fun finish() {\nsuper.finish()\ntry {\n// true sets the torch in OFF mode\ncameraManager!!.setTorchMode(getCameraID!!, false)// Inform the user about the flashlight\n// status using Toast message\nToast.makeText(this@SlaphScreen, \"Flashlight is turned OFF\", Toast.LENGTH_SHORT).show()\n} catch (e: CameraAccessException) {\n// prints stack trace on standard error\n// output error stream\ne.printStackTrace()\n}\n}\n}\n// This code is added by Ujjwal Kumar BhardwajRead about the printStackTrace() function here: Throwable printStackTrace() method in Java with Examples.\nAfter handling the ToggleButton one needs to test the application under a physical android device. Because if you run the application in the emulator which comes with android studio, the app is going to crash as soon as ToggleButton is clicked, because the emulator device wouldn\u2019t come with the camera flash unit.\nThis method of accessing the camera hardware doesn\u2019t require special permission from the user to access the camera unit. Because in this we are accessing the flash unit through only camera ID (whether it\u2019s a front camera or back camera).Output:https://media.geeksforgeeks.org/wp-content/uploads/20200921184957/GFG_frame_nexus_5.mp4",
"input": "",
"output": "g Firebase in AndroidFirebase is a mobile and web application development platform. It provides services that a web application or mobile application might require. Firebase provides email and password authentication without any overhead of building backend for user authentication.\nSteps for firebase user authentication are:Step 1:\nCreate a new project on android studio or open an existing project in which you want to add authentication and add the firebase to that android application.Steps to add firebase are very well explained in following link : https://www.geeksforgeeks.org/adding-firebase-to-android-app/Step 2:\nGo to Firebase console (http://console.firebase.google.com/) navigate to your application, and under the authentication tab, enable email/pass authentication.Step 3: activity_registration.xml\nThis is your sign-up activity. It has two EditTexts, a TextView, a Button and a Progress Bar. All these views are contained in a Linear Layout with vertical orientation. EditTexts are used to get email and password from the user. Button is used for signup purpose after filling username and password.\nComplete xml code for registration activity(activity_registration) is:activity_registration.xml \n \n() { @Override\npublic void onComplete(@NonNull Task task) \n{ \nif (task.isSuccessful()) { \nToast.makeText(getApplicationContext(), \n\"Registration successful!\", \nToast.LENGTH_LONG) \n.show(); // hide the progress bar \nprogressBar.setVisibility(View.GONE); // if the user created intent to login activity \nIntent intent \n= new Intent(RegistrationActivity.this, \nMainActivity.class); \nstartActivity(intent); \n} \nelse { // Registration failed \nToast.makeText( \ngetApplicationContext(), \n\"Registration failed!!\"\n+ \" Please try again later\", \nToast.LENGTH_LONG) \n.show(); // hide the progress bar \nprogressBar.setVisibility(View.GONE); \n} \n} \n}); \n} \n} "
},
{
"instruction": "g Firebase in AndroidFirebase is a mobile and web application development platform. It provides services that a web application or mobile application might require. Firebase provides email and password authentication without any overhead of building backend for user authentication.\nSteps for firebase user authentication are:Step 1:\nCreate a new project on android studio or open an existing project in which you want to add authentication and add the firebase to that android application.Steps to add firebase are very well explained in following link : https://www.geeksforgeeks.org/adding-firebase-to-android-app/Step 2:\nGo to Firebase console (http://console.firebase.google.com/) navigate to your application, and under the authentication tab, enable email/pass authentication.Step 3: activity_registration.xml\nThis is your sign-up activity. It has two EditTexts, a TextView, a Button and a Progress Bar. All these views are contained in a Linear Layout with vertical orientation. EditTexts are used to get email and password from the user. Button is used for signup purpose after filling username and password.\nComplete xml code for registration activity(activity_registration) is:activity_registration.xml \n \n() { @Override\npublic void onComplete(@NonNull Task task) \n{ \nif (task.isSuccessful()) { \nToast.makeText(getApplicationContext(), \n\"Registration successful!\", \nToast.LENGTH_LONG) \n.show(); // hide the progress bar \nprogressBar.setVisibility(View.GONE); // if the user created intent to login activity \nIntent intent \n= new Intent(RegistrationActivity.this, \nMainActivity.class); \nstartActivity(intent); \n} \nelse { // Registration failed \nToast.makeText( \ngetApplicationContext(), \n\"Registration failed!!\"\n+ \" Please try again later\", \nToast.LENGTH_LONG) \n.show(); // hide the progress bar \nprogressBar.setVisibility(View.GONE); \n} \n} \n}); \n} \n} ",
"input": "",
"output": "id with ExampleAn Absolute Layout allows you to specify the exact location i.e. X and Y coordinates of its children with respect to the origin at the top left corner of the layout. The absolute layout is less flexible and harder to maintain for varying sizes of screens that\u2019s why it is not recommended. Although Absolute Layout is deprecated now.\nSome of the important Absolute Layout attributes are the following:\nandroid:id: It uniquely specifies the absolute layoutandroid:layout_x: It specifies X-Coordinate of the Views (Possible values of this is in density-pixel or pixel)android:layout_y: It specifies Y-Coordinate of the Views (Possible values of this is in dp or px)The Syntax for Absolute LayoutXML\n\nExampleIn this example, we are going to create a basic application with Absolute Layout that is having two TextView. Note that we are going to implement this project using the Java language.\nStep by Step ImplementationStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Create the layout file\nFor this go to app > res > layout > activity_main.xml file and change the Constraint Layout to Absolute Layout and add TextViews. Below is the code snippet for the activity_main.xml file.XML\n \n Before moving further let\u2019s add some color attributes in order to enhance the app bar. Go to app > res > values > colors.xml and add the following color attributes. XML \n #0F9D58 \n #16E37F \n #03DAC5 \n Step 3: Working with the MainActivity.java file\nIn this step, we will initialize the TextViews in our MainActivity.java file.Javaimport android.os.Bundle;\nimport android.widget.TextView;\nimport androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity { TextView heading, subHeading; @Override\n protected void onCreate(Bundle savedInstanceState)\n {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Referencing the TextViews\n heading = (TextView)findViewById(R.id.heading);\n subHeading\n = (TextView)findViewById(R.id.subHeading); // Setting text dynamically\n heading.setText(\"Computer Science Portal\");\n subHeading.setText(\"GeeksForGeeks\");\n }\n}Output: Run On EmulatorYou will see that TextViews are having fixed X and Y Coordinates."
},
{
"instruction": "id with ExampleAn Absolute Layout allows you to specify the exact location i.e. X and Y coordinates of its children with respect to the origin at the top left corner of the layout. The absolute layout is less flexible and harder to maintain for varying sizes of screens that\u2019s why it is not recommended. Although Absolute Layout is deprecated now.\nSome of the important Absolute Layout attributes are the following:\nandroid:id: It uniquely specifies the absolute layoutandroid:layout_x: It specifies X-Coordinate of the Views (Possible values of this is in density-pixel or pixel)android:layout_y: It specifies Y-Coordinate of the Views (Possible values of this is in dp or px)The Syntax for Absolute LayoutXML\n\nExampleIn this example, we are going to create a basic application with Absolute Layout that is having two TextView. Note that we are going to implement this project using the Java language.\nStep by Step ImplementationStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Create the layout file\nFor this go to app > res > layout > activity_main.xml file and change the Constraint Layout to Absolute Layout and add TextViews. Below is the code snippet for the activity_main.xml file.XML\n \n Before moving further let\u2019s add some color attributes in order to enhance the app bar. Go to app > res > values > colors.xml and add the following color attributes. XML \n #0F9D58 \n #16E37F \n #03DAC5 \n Step 3: Working with the MainActivity.java file\nIn this step, we will initialize the TextViews in our MainActivity.java file.Javaimport android.os.Bundle;\nimport android.widget.TextView;\nimport androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity { TextView heading, subHeading; @Override\n protected void onCreate(Bundle savedInstanceState)\n {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Referencing the TextViews\n heading = (TextView)findViewById(R.id.heading);\n subHeading\n = (TextView)findViewById(R.id.subHeading); // Setting text dynamically\n heading.setText(\"Computer Science Portal\");\n subHeading.setText(\"GeeksForGeeks\");\n }\n}Output: Run On EmulatorYou will see that TextViews are having fixed X and Y Coordinates.",
"input": "",
"output": "roidState Progress Bar is one of the main features that we see in many applications. We can get to see this feature in ticket booking apps, educational apps. This progress bar helps to tell the user the steps to be carried out for performing a task. In this article, we are going to see how to implement State Progress Bar in Android. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Application of State Progress BarUsed in most of the service providing applications such as ticket booking, exam form filling, and many more.\nThis State Progress Bar helps the user\u2019s steps to be carried out for performing the task.\nUse in various exam form-filling applications.Attributes of State Progress BarAttributesDescriptionlayout_width\nUse for giving specific width.layout_height\nUse for giving specific height.spb_maxStateNumber\nUse to display the number of states used in the app.spb_currentStateNumber\nUse to display the current state.spb_stateBackgroundColor\nUse to display background color.spb_stateForegroundColor\nUse to display Foreground color.spb_animateToCurrentProgressState\nGives Animation to the current Progress state.spb_checkStateCompleted\nCheck whether the state is completed or not.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add dependency of State Progress Bar library in build.gradle file\nThen Navigate to gradle scripts and then to build.gradle(Module) level. Add below line in build.gradle file in the dependencies section.implementation \u2018com.kofigyan.stateprogressbar:stateprogressbar:1.0.0\u2019Now click on Sync now it will sync your all files in build.gradle().\nStep 3: Create a new State Progress Bar in your activity_main.xml file\nNavigate to the app > res > layout to open the activity_main.xml file. Below is the code for the activity_main.xml file.XML \n \n \n \n \n \nStep 5: Creating a layout file for our slider item\nNow we will create an item that we will be displaying in our slider. So for creating a new layout navigate to the app > res > layout > Right-click on it > Click on New > layout resource file and name it as slider_layout and add below code to it. XML\n \n Step 6: Creating a Modal class for storing all the data for Slider items\nFor creating a new Modal class navigate to the app > java > your app\u2019s package name > Right-click on it and click on New > Java class and name it as SliderModal. After creating this class add the below code to it. Javapublic class SliderModal { // string variable for storing title,\n // image url and description.\n private String title;\n private String heading;\n private String imgUrl; public SliderModal() {\n // empty constructor is required\n // when using firebase\n } // creating getter methods.\n public String getTitle() {\n return title;\n } public void setTitle(String title) {\n this.title = title;\n } public String getHeading() {\n return heading;\n } // creating setter methods\n public void setHeading(String heading) {\n this.heading = heading;\n } public String getImgUrl() {\n return imgUrl;\n } public void setImgUrl(String imgUrl) {\n this.imgUrl = imgUrl;\n }\n \n // constructor for our modal class\n public SliderModal(String title, String heading, String imgUrl) {\n this.title = title;\n this.heading = heading;\n this.imgUrl = imgUrl;\n }\n}Step 7: Create an Adapter class for setting data to each view\nFor creating a new Adapter class. Navigate to the app > java > your app\u2019s package name > Right-click on it > New Java class > name it as SliderAdapter and add the below code to it. Comments are added inside the code to understand the code in more detail.Javaimport android.content.Context;\nimport android.view.LayoutInflater;\nimport android.view.View;\nimport android.view.ViewGroup;\nimport android.widget.ImageView;\nimport android.widget.RelativeLayout;\nimport android.widget.TextView;import androidx.annotation.NonNull;\nimport androidx.viewpager.widget.PagerAdapter;import com.squareup.picasso.Picasso;import java.util.ArrayList;public class SliderAdapter extends PagerAdapter { // creating variables for layout inflater,\n // context and array list.\n LayoutInflater layoutInflater;\n Context context;\n ArrayList sliderModalArrayList; // creating constructor.\n public SliderAdapter(Context context, ArrayList sliderModalArrayList) {\n this.context = context;\n this.sliderModalArrayList = sliderModalArrayList;\n } @Override\n public int getCount() {\n // inside get count method returning \n // the size of our array list.\n return sliderModalArrayList.size();\n }\n \n @Override\n public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {\n // inside isViewFromobject method we are \n // returning our Relative layout object.\n return view == (RelativeLayout) object;\n } @NonNull\n @Override\n public Object instantiateItem(@NonNull ViewGroup container, int position) {\n // in this method we will initialize all our layout items\n // and inflate our layout file as well.\n layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);\n \n // below line is use to inflate the layout file which we created.\n View view = layoutInflater.inflate(R.layout.slider_layout, container, false);\n \n // initializing our views.\n ImageView imageView = view.findViewById(R.id.idIV);\n TextView titleTV = view.findViewById(R.id.idTVtitle);\n TextView headingTV = view.findViewById(R.id.idTVheading); // setting data to our views.\n SliderModal modal = sliderModalArrayList.get(position);\n titleTV.setText(modal.getTitle());\n headingTV.setText(modal.getHeading());\n Picasso.get().load(modal.getImgUrl()).into(imageView); // after setting the data to our views we \n // are adding the view to our container.\n container.addView(view);\n \n // at last we are returning the view.\n return view;\n } @Override\n public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {\n // this is a destroy view method which\n // is use to remove a view.\n container.removeView((RelativeLayout) object);\n }\n}Step 8: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Javaimport android.os.Bundle;\nimport android.text.Html;\nimport android.widget.LinearLayout;\nimport android.widget.TextView;\nimport android.widget.Toast;import androidx.annotation.NonNull;\nimport androidx.appcompat.app.AppCompatActivity;\nimport androidx.viewpager.widget.ViewPager;import com.google.android.gms.tasks.OnFailureListener;\nimport com.google.android.gms.tasks.OnSuccessListener;\nimport com.google.firebase.firestore.DocumentSnapshot;\nimport com.google.firebase.firestore.FirebaseFirestore;\nimport com.google.firebase.firestore.QuerySnapshot;import java.util.ArrayList;\nimport java.util.List;public class MainActivity extends AppCompatActivity { // creating variables for view pager, \n // LinearLayout, adapter and our array list.\n private ViewPager viewPager;\n private LinearLayout dotsLL;\n SliderAdapter adapter;\n private ArrayList sliderModalArrayList;\n private TextView[] dots;\n int size;\n FirebaseFirestore db; @Override\n protected void onCreate(Bundle savedInstanceState) {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main);\n db = FirebaseFirestore.getInstance();\n \n // initializing all our views.\n viewPager = findViewById(R.id.idViewPager);\n dotsLL = findViewById(R.id.idLLDots);\n \n // in below line we are creating a new array list.\n sliderModalArrayList = new ArrayList<>();\n loadDataFromFirebase(); // calling method to add dots indicator\n addDots(size, 0);\n \n // below line is use to call on page \n // change listener method.\n viewPager.addOnPageChangeListener(viewListener);\n } private void loadDataFromFirebase() { // below line is use to get data from Firebase\n // firestore using collection in android.\n db.collection(\"SliderData\").get()\n .addOnSuccessListener(new OnSuccessListener() {\n @Override\n public void onSuccess(QuerySnapshot queryDocumentSnapshots) {\n // after getting the data we are calling on success method\n // and inside this method we are checking if the received\n // query snapshot is empty or not.\n if (!queryDocumentSnapshots.isEmpty()) {\n // if the snapshot is not empty we are hiding our\n // progress bar and adding our data in a list.\n List list = queryDocumentSnapshots.getDocuments();\n for (DocumentSnapshot d : list) {\n // after getting this list we are passing \n // that list to our object class.\n SliderModal sliderModal = d.toObject(SliderModal.class);\n \n // after getting data from Firebase we are\n // storing that data in our array list\n sliderModalArrayList.add(sliderModal);\n }\n // below line is use to add our array list to adapter class.\n adapter = new SliderAdapter(MainActivity.this, sliderModalArrayList);\n \n // below line is use to set our\n // adapter to our view pager.\n viewPager.setAdapter(adapter);\n \n // we are storing the size of our \n // array list in a variable.\n size = sliderModalArrayList.size();\n } else {\n // if the snapshot is empty we are displaying a toast message.\n Toast.makeText(MainActivity.this, \"No data found in Database\", Toast.LENGTH_SHORT).show();\n }\n }\n }).addOnFailureListener(new OnFailureListener() {\n @Override\n public void onFailure(@NonNull Exception e) {\n // we are displaying a toast message when\n // we get any error from Firebase.\n Toast.makeText(MainActivity.this, \"Fail to load data..\", Toast.LENGTH_SHORT).show();\n }\n });\n }\n \n private void addDots(int size, int pos) {\n // inside this method we are\n // creating a new text view.\n dots = new TextView[size];\n \n // below line is use to remove all \n // the views from the linear layout.\n dotsLL.removeAllViews();\n \n // running a for loop to add number\n // of dots to our slider.\n for (int i = 0; i < size; i++) {\n // below line is use to add the dots \n // and modify its color.\n dots[i] = new TextView(this);\n dots[i].setText(Html.fromHtml(\"\u2022\"));\n dots[i].setTextSize(35);\n \n // below line is called when the\n // dots are not selected.\n dots[i].setTextColor(getResources().getColor(R.color.white));\n dotsLL.addView(dots[i]);\n }\n if (dots.length > 0) {\n // this line is called when the dots \n // inside linear layout are selected\n dots[pos].setTextColor(getResources().getColor(R.color.purple_200));\n }\n } // creating a method for view pager for on page change listener.\n ViewPager.OnPageChangeListener viewListener = new ViewPager.OnPageChangeListener() {\n @Override\n public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override\n public void onPageSelected(int position) {\n // we are calling our dots method to \n // change the position of selected dots.\n addDots(size, position);\n } @Override\n public void onPageScrollStateChanged(int state) { }\n };\n}After adding the above code add the data to Firebase Firestore in Android. \nStep 9: Adding the data to Firebase Firestore in Android\nSearch for Firebase in your browser and go to that website and you will get to see the below screen. After clicking on Go to Console option. Click on your project which is shown below.After clicking on your project you will get to see the below screen. After clicking on this project you will get to see the below screen. After clicking on Create Database option you will get to see the below screen. Inside this screen, we have to select the Start in test mode option. We are using test mode because we are not setting authentication inside our app. So we are selecting Start in test mode. After selecting on test mode click on the Next option and you will get to see the below screen. Inside this screen, we just have to click on Enable button to enable our Firebase Firestore database. After completing this process we have to add the data inside our Firebase Console. For adding data to our Firebase Console. \nYou have to click on Start Collection Option and give the collection name as SliderData. After creating a collection you have to click on Autoid option for creating the first document. Inside this create three fields as title, heading, and imgUrl and add values inside that fields. Add multiple documents in a similar way inside your Firebase Console. After that run your app and see the output of the app. After adding this data to Firebase run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210117233915/Screenrecorder-2021-01-17-23-37-46-620.mp4\n"
},
{
"instruction": "tro Slider in Android using Firebase Firestore?We have seen creating a basic Intro Slider in Android which is used to inform our users regarding the features of our app and many more. In this article, we will take a look at the implementation of dynamic Intro Slider in our app with the help of Firebase. With the help of Firebase Firestore, we can change all the data dynamically from Firebase Console. Now let\u2019s move towards the implementation.\nWhat we are going to build in this project?We will be building a simple Intro Slider in which we will load all the data from the Firebase Console and display that data in our slider. With the help of Firebase, we can dynamically update our data according to our requirements. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Step by Step Implementation Step 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Connect your app to Firebase\nAfter creating a new project. Navigate to the Tools option on the top bar. Inside that click on Firebase. After clicking on Firebase, you can get to see the right column mentioned below in the screenshot.Inside that column Navigate to Firebase Cloud Firestore. Click on that option and you will get to see two options on Connect app to Firebase and Add Cloud Firestore to your app. Click on Connect now option and your app will be connected to Firebase. After that click on the second option and now your App is connected to Firebase. After connecting your app to Firebase you will get to see the below screen. After that verify that dependency for the Firebase Firestore database has been added to our Gradle file. Navigate to app > Gradle Scripts inside that file check weather below dependency is added or not. If the below dependency is not present in your build.gradle file. Add the below dependency in the dependencies section. \nimplementation \u2018com.google.firebase:firebase-firestore:22.0.1\u2019\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019\nAfter adding this dependency sync your project and now we are ready for creating our app. if you want to know more about connecting your app to Firebase. Refer to this article to get in detail about How to add Firebase to Android App. As we are loading images from URL so we have to use Picasso.\nStep 3: Adding permissions for the Internet\nAs we will be loading images from the URL, so we have to add permissions for the internet in your AndroidManifest.xml file. For adding permissions. Navigate to the app > AndroidManifest.xml file and add the below permissions. XML\n \n \n \nStep 5: Creating a layout file for our slider item\nNow we will create an item that we will be displaying in our slider. So for creating a new layout navigate to the app > res > layout > Right-click on it > Click on New > layout resource file and name it as slider_layout and add below code to it. XML\n \n Step 6: Creating a Modal class for storing all the data for Slider items\nFor creating a new Modal class navigate to the app > java > your app\u2019s package name > Right-click on it and click on New > Java class and name it as SliderModal. After creating this class add the below code to it. Javapublic class SliderModal { // string variable for storing title,\n // image url and description.\n private String title;\n private String heading;\n private String imgUrl; public SliderModal() {\n // empty constructor is required\n // when using firebase\n } // creating getter methods.\n public String getTitle() {\n return title;\n } public void setTitle(String title) {\n this.title = title;\n } public String getHeading() {\n return heading;\n } // creating setter methods\n public void setHeading(String heading) {\n this.heading = heading;\n } public String getImgUrl() {\n return imgUrl;\n } public void setImgUrl(String imgUrl) {\n this.imgUrl = imgUrl;\n }\n \n // constructor for our modal class\n public SliderModal(String title, String heading, String imgUrl) {\n this.title = title;\n this.heading = heading;\n this.imgUrl = imgUrl;\n }\n}Step 7: Create an Adapter class for setting data to each view\nFor creating a new Adapter class. Navigate to the app > java > your app\u2019s package name > Right-click on it > New Java class > name it as SliderAdapter and add the below code to it. Comments are added inside the code to understand the code in more detail.Javaimport android.content.Context;\nimport android.view.LayoutInflater;\nimport android.view.View;\nimport android.view.ViewGroup;\nimport android.widget.ImageView;\nimport android.widget.RelativeLayout;\nimport android.widget.TextView;import androidx.annotation.NonNull;\nimport androidx.viewpager.widget.PagerAdapter;import com.squareup.picasso.Picasso;import java.util.ArrayList;public class SliderAdapter extends PagerAdapter { // creating variables for layout inflater,\n // context and array list.\n LayoutInflater layoutInflater;\n Context context;\n ArrayList sliderModalArrayList; // creating constructor.\n public SliderAdapter(Context context, ArrayList sliderModalArrayList) {\n this.context = context;\n this.sliderModalArrayList = sliderModalArrayList;\n } @Override\n public int getCount() {\n // inside get count method returning \n // the size of our array list.\n return sliderModalArrayList.size();\n }\n \n @Override\n public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {\n // inside isViewFromobject method we are \n // returning our Relative layout object.\n return view == (RelativeLayout) object;\n } @NonNull\n @Override\n public Object instantiateItem(@NonNull ViewGroup container, int position) {\n // in this method we will initialize all our layout items\n // and inflate our layout file as well.\n layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);\n \n // below line is use to inflate the layout file which we created.\n View view = layoutInflater.inflate(R.layout.slider_layout, container, false);\n \n // initializing our views.\n ImageView imageView = view.findViewById(R.id.idIV);\n TextView titleTV = view.findViewById(R.id.idTVtitle);\n TextView headingTV = view.findViewById(R.id.idTVheading); // setting data to our views.\n SliderModal modal = sliderModalArrayList.get(position);\n titleTV.setText(modal.getTitle());\n headingTV.setText(modal.getHeading());\n Picasso.get().load(modal.getImgUrl()).into(imageView); // after setting the data to our views we \n // are adding the view to our container.\n container.addView(view);\n \n // at last we are returning the view.\n return view;\n } @Override\n public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {\n // this is a destroy view method which\n // is use to remove a view.\n container.removeView((RelativeLayout) object);\n }\n}Step 8: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Javaimport android.os.Bundle;\nimport android.text.Html;\nimport android.widget.LinearLayout;\nimport android.widget.TextView;\nimport android.widget.Toast;import androidx.annotation.NonNull;\nimport androidx.appcompat.app.AppCompatActivity;\nimport androidx.viewpager.widget.ViewPager;import com.google.android.gms.tasks.OnFailureListener;\nimport com.google.android.gms.tasks.OnSuccessListener;\nimport com.google.firebase.firestore.DocumentSnapshot;\nimport com.google.firebase.firestore.FirebaseFirestore;\nimport com.google.firebase.firestore.QuerySnapshot;import java.util.ArrayList;\nimport java.util.List;public class MainActivity extends AppCompatActivity { // creating variables for view pager, \n // LinearLayout, adapter and our array list.\n private ViewPager viewPager;\n private LinearLayout dotsLL;\n SliderAdapter adapter;\n private ArrayList sliderModalArrayList;\n private TextView[] dots;\n int size;\n FirebaseFirestore db; @Override\n protected void onCreate(Bundle savedInstanceState) {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main);\n db = FirebaseFirestore.getInstance();\n \n // initializing all our views.\n viewPager = findViewById(R.id.idViewPager);\n dotsLL = findViewById(R.id.idLLDots);\n \n // in below line we are creating a new array list.\n sliderModalArrayList = new ArrayList<>();\n loadDataFromFirebase(); // calling method to add dots indicator\n addDots(size, 0);\n \n // below line is use to call on page \n // change listener method.\n viewPager.addOnPageChangeListener(viewListener);\n } private void loadDataFromFirebase() { // below line is use to get data from Firebase\n // firestore using collection in android.\n db.collection(\"SliderData\").get()\n .addOnSuccessListener(new OnSuccessListener() {\n @Override\n public void onSuccess(QuerySnapshot queryDocumentSnapshots) {\n // after getting the data we are calling on success method\n // and inside this method we are checking if the received\n // query snapshot is empty or not.\n if (!queryDocumentSnapshots.isEmpty()) {\n // if the snapshot is not empty we are hiding our\n // progress bar and adding our data in a list.\n List list = queryDocumentSnapshots.getDocuments();\n for (DocumentSnapshot d : list) {\n // after getting this list we are passing \n // that list to our object class.\n SliderModal sliderModal = d.toObject(SliderModal.class);\n \n // after getting data from Firebase we are\n // storing that data in our array list\n sliderModalArrayList.add(sliderModal);\n }\n // below line is use to add our array list to adapter class.\n adapter = new SliderAdapter(MainActivity.this, sliderModalArrayList);\n \n // below line is use to set our\n // adapter to our view pager.\n viewPager.setAdapter(adapter);\n \n // we are storing the size of our \n // array list in a variable.\n size = sliderModalArrayList.size();\n } else {\n // if the snapshot is empty we are displaying a toast message.\n Toast.makeText(MainActivity.this, \"No data found in Database\", Toast.LENGTH_SHORT).show();\n }\n }\n }).addOnFailureListener(new OnFailureListener() {\n @Override\n public void onFailure(@NonNull Exception e) {\n // we are displaying a toast message when\n // we get any error from Firebase.\n Toast.makeText(MainActivity.this, \"Fail to load data..\", Toast.LENGTH_SHORT).show();\n }\n });\n }\n \n private void addDots(int size, int pos) {\n // inside this method we are\n // creating a new text view.\n dots = new TextView[size];\n \n // below line is use to remove all \n // the views from the linear layout.\n dotsLL.removeAllViews();\n \n // running a for loop to add number\n // of dots to our slider.\n for (int i = 0; i < size; i++) {\n // below line is use to add the dots \n // and modify its color.\n dots[i] = new TextView(this);\n dots[i].setText(Html.fromHtml(\"\u2022\"));\n dots[i].setTextSize(35);\n \n // below line is called when the\n // dots are not selected.\n dots[i].setTextColor(getResources().getColor(R.color.white));\n dotsLL.addView(dots[i]);\n }\n if (dots.length > 0) {\n // this line is called when the dots \n // inside linear layout are selected\n dots[pos].setTextColor(getResources().getColor(R.color.purple_200));\n }\n } // creating a method for view pager for on page change listener.\n ViewPager.OnPageChangeListener viewListener = new ViewPager.OnPageChangeListener() {\n @Override\n public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override\n public void onPageSelected(int position) {\n // we are calling our dots method to \n // change the position of selected dots.\n addDots(size, position);\n } @Override\n public void onPageScrollStateChanged(int state) { }\n };\n}After adding the above code add the data to Firebase Firestore in Android. \nStep 9: Adding the data to Firebase Firestore in Android\nSearch for Firebase in your browser and go to that website and you will get to see the below screen. After clicking on Go to Console option. Click on your project which is shown below.After clicking on your project you will get to see the below screen. After clicking on this project you will get to see the below screen. After clicking on Create Database option you will get to see the below screen. Inside this screen, we have to select the Start in test mode option. We are using test mode because we are not setting authentication inside our app. So we are selecting Start in test mode. After selecting on test mode click on the Next option and you will get to see the below screen. Inside this screen, we just have to click on Enable button to enable our Firebase Firestore database. After completing this process we have to add the data inside our Firebase Console. For adding data to our Firebase Console. \nYou have to click on Start Collection Option and give the collection name as SliderData. After creating a collection you have to click on Autoid option for creating the first document. Inside this create three fields as title, heading, and imgUrl and add values inside that fields. Add multiple documents in a similar way inside your Firebase Console. After that run your app and see the output of the app. After adding this data to Firebase run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210117233915/Screenrecorder-2021-01-17-23-37-46-620.mp4\n",
"input": "",
"output": " Google Maps in Android?We have seen the implementation of Google Maps in Android along with markers on it. But many apps provide features so that users can specify the location on which they have to place markers. So in this article, we will implement a SearchView in our Android app so that we can search a location name and add a marker to that location.\nWhat we are going to build in this article?\nWe will be building a simple application in which we will be displaying a simple Google map and a SearchView. Inside that search view when users enter any location name then we will add a marker to that location on Google Maps. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.https://media.geeksforgeeks.org/wp-content/uploads/20210126163040/Screenrecorder-2021-01-26-16-21-59-991.mp4\nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language. Make sure to select Maps Activity while creating a new Project.\nStep 2: Generating an API key for using Google Maps\nTo generate the API key for Maps you may refer to How to Generate API Key for Using Google Maps in Android. After generating your API key for Google Maps. We have to add this key to our Project. For adding this key in our app navigate to the values folder > google_maps_api.xml file and at line 23 you have to add your API key in the place of YOUR_API_KEY.\nStep 3: Working with the activity_maps.xml file\nAs we are adding SearchView to our Google Maps for searching a location and adding a marker on that location. So we have to add a search view to our activity_maps.xml file. For adding SearchView, navigate to the app > res > layout > activity_maps.xml and add the below code to it. Comments are added in the code to get to know in more detail.XML \n \n addressList = null; // checking if the entered location is null or not. \nif (location != null || location.equals(\"\")) { \n// on below line we are creating and initializing a geo coder. \nGeocoder geocoder = new Geocoder(MapsActivity.this); \ntry { \n// on below line we are getting location from the \n// location name and adding that location to address list. \naddressList = geocoder.getFromLocationName(location, 1); \n} catch (IOException e) { \ne.printStackTrace(); \n} \n// on below line we are getting the location \n// from our list a first position. \nAddress address = addressList.get(0); // on below line we are creating a variable for our location \n// where we will add our locations latitude and longitude. \nLatLng latLng = new LatLng(address.getLatitude(), address.getLongitude()); // on below line we are adding marker to that position. \nmMap.addMarker(new MarkerOptions().position(latLng).title(location)); // below line is to animate camera to that position. \nmMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 10)); \n} \nreturn false; \n} @Override\npublic boolean onQueryTextChange(String newText) { \nreturn false; \n} \n}); \n// at last we calling our map fragment to update. \nmapFragment.getMapAsync(this); \n} @Override\npublic void onMapReady(GoogleMap googleMap) { \nmMap = googleMap; \n} \n}Now run your app and see the output of the app.\nOutput:\nhttps://media.geeksforgeeks.org/wp-content/uploads/20210126163040/Screenrecorder-2021-01-26-16-21-59-991.mp4"
},
{
"instruction": " Google Maps in Android?We have seen the implementation of Google Maps in Android along with markers on it. But many apps provide features so that users can specify the location on which they have to place markers. So in this article, we will implement a SearchView in our Android app so that we can search a location name and add a marker to that location.\nWhat we are going to build in this article?\nWe will be building a simple application in which we will be displaying a simple Google map and a SearchView. Inside that search view when users enter any location name then we will add a marker to that location on Google Maps. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.https://media.geeksforgeeks.org/wp-content/uploads/20210126163040/Screenrecorder-2021-01-26-16-21-59-991.mp4\nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language. Make sure to select Maps Activity while creating a new Project.\nStep 2: Generating an API key for using Google Maps\nTo generate the API key for Maps you may refer to How to Generate API Key for Using Google Maps in Android. After generating your API key for Google Maps. We have to add this key to our Project. For adding this key in our app navigate to the values folder > google_maps_api.xml file and at line 23 you have to add your API key in the place of YOUR_API_KEY.\nStep 3: Working with the activity_maps.xml file\nAs we are adding SearchView to our Google Maps for searching a location and adding a marker on that location. So we have to add a search view to our activity_maps.xml file. For adding SearchView, navigate to the app > res > layout > activity_maps.xml and add the below code to it. Comments are added in the code to get to know in more detail.XML \n \n addressList = null; // checking if the entered location is null or not. \nif (location != null || location.equals(\"\")) { \n// on below line we are creating and initializing a geo coder. \nGeocoder geocoder = new Geocoder(MapsActivity.this); \ntry { \n// on below line we are getting location from the \n// location name and adding that location to address list. \naddressList = geocoder.getFromLocationName(location, 1); \n} catch (IOException e) { \ne.printStackTrace(); \n} \n// on below line we are getting the location \n// from our list a first position. \nAddress address = addressList.get(0); // on below line we are creating a variable for our location \n// where we will add our locations latitude and longitude. \nLatLng latLng = new LatLng(address.getLatitude(), address.getLongitude()); // on below line we are adding marker to that position. \nmMap.addMarker(new MarkerOptions().position(latLng).title(location)); // below line is to animate camera to that position. \nmMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 10)); \n} \nreturn false; \n} @Override\npublic boolean onQueryTextChange(String newText) { \nreturn false; \n} \n}); \n// at last we calling our map fragment to update. \nmapFragment.getMapAsync(this); \n} @Override\npublic void onMapReady(GoogleMap googleMap) { \nmMap = googleMap; \n} \n}Now run your app and see the output of the app.\nOutput:\nhttps://media.geeksforgeeks.org/wp-content/uploads/20210126163040/Screenrecorder-2021-01-26-16-21-59-991.mp4",
"input": "",
"output": " in an Android ApplicationToggleButton is basically a stop/play or on/off button with an indicator light indicating the current state of ToggleButton. ToggleButton is widely used, some examples are on/off audio, Bluetooth, WiFi, hot-spot etc. This is a subclass of Composite Button.\nhttps://media.geeksforgeeks.org/wp-content/uploads/20240603163054/Toggle_Button.mp4\nToggleButton allows users to change settings between two states from their phone\u2019s Settings menu such as turning their WiFi, Bluetooth, etc. on / off. Since the Android 4.0 version (API level 14), it has another type of toggle button called a switch which provides user slider control. \nNote: Programmatically, the isChecked() method is used to check the current state of the toggle button. This method returns a boolean value. If a toggle button is ON, this returns true otherwise it returns false. Below is an example in which the toggle button is used.\nSteps by Step Implementation of Toggle ButtonStep 1: Create a New Project To create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio.\nNote:SelectJavaas the programming language.\nStep 2: Creating a layout to display the ToggleButtonImportant Operations can be performed using XML Attributes:\nOperation\nXML Attribute\nandroid:textOn\nUsed to change the text to be displayed when the button is On. By default text is \u201cON\u201d\nandroid:textOff\nUsed to change the text to be displayed when the button is Off. By default text is \u201cOFF\u201d\nandroid:disabledAlpha\nThe alpha to apply to the indicator when disabled.\nNavigate res>layout>activity_main.xml:ges the state of the button\nIn this step, open the XML file and add the code to display the toggle button and a textview.acticity_main.xml\n Step 3: Using Methods Associated with the ToggleButtonWe will update the methods to test the full ability of out Togglebutton.\nMethod\nDescription\nCharSquence getTextOn()\nReturns the text when button is On\nCharSquence getTextOff()\nReturns the text when button is Off\nvoid setChecked(boolean checked)\nChanges the state of the button\nNavigate Open the app -> Java -> Package -> Mainactivity.java\nIn this step, open MainActivity and add the below code to initialize the toggle button and add onToggleClick method which will be invoked when the user clicks on the toggle button. This method changes the text in textview. MainActivity.javaimport android.os.Bundle;\nimport android.view.View;\nimport android.widget.TextView;\nimport android.widget.ToggleButton;\nimport androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity { ToggleButton togglebutton;\n TextView textview; @Override\n protected void onCreate(Bundle savedInstanceState) {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Initialize the toggle button and text view\n togglebutton = (ToggleButton) findViewById(R.id.toggleButton);\n textview = (TextView) findViewById(R.id.textView);\n } // Method is called when the toggle button is clicked\n public void onToggleClick(View view) {\n if (togglebutton.isChecked()) {\n textview.setText(\"Toggle is ON\");\n } else {\n textview.setText(\"Toggle is OFF\");\n }\n }\n}MainActivity.ktpackage com.gfg.toggle_buttonimport android.os.Bundle\nimport android.view.View\nimport android.widget.TextView\nimport android.widget.ToggleButton\nimport androidx.activity.enableEdgeToEdge\nimport androidx.appcompat.app.AppCompatActivity\nimport androidx.core.view.ViewCompat\nimport androidx.core.view.WindowInsetsCompatclass MainActivity : AppCompatActivity() {\n lateinit var toggleButton: ToggleButton\n lateinit var textView: TextView\n \n override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_main) // Initialize the toggle button and text view\n toggleButton = findViewById(R.id.button_toggle)\n textView = findViewById(R.id.textView1) } // Method is called when the toggle button is clicked\n fun onToggleClick(view: View) {\n if (toggleButton.isChecked) {\n textView.text = \"Toggle is ON\"\n } else {\n textView.text = \"Toggle is OFF\"\n }\n }\n}Output:\nNow connect your device with USB cable and launch the application. You will see a toggle button. Click on the toggle button which will display the status of the toggle button.The Final Application Created Can be downloaded from this link \u2013GitHub Link for the Toggle Key in Android Application"
},
{
"instruction": " in an Android ApplicationToggleButton is basically a stop/play or on/off button with an indicator light indicating the current state of ToggleButton. ToggleButton is widely used, some examples are on/off audio, Bluetooth, WiFi, hot-spot etc. This is a subclass of Composite Button.\nhttps://media.geeksforgeeks.org/wp-content/uploads/20240603163054/Toggle_Button.mp4\nToggleButton allows users to change settings between two states from their phone\u2019s Settings menu such as turning their WiFi, Bluetooth, etc. on / off. Since the Android 4.0 version (API level 14), it has another type of toggle button called a switch which provides user slider control. \nNote: Programmatically, the isChecked() method is used to check the current state of the toggle button. This method returns a boolean value. If a toggle button is ON, this returns true otherwise it returns false. Below is an example in which the toggle button is used.\nSteps by Step Implementation of Toggle ButtonStep 1: Create a New Project To create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio.\nNote:SelectJavaas the programming language.\nStep 2: Creating a layout to display the ToggleButtonImportant Operations can be performed using XML Attributes:\nOperation\nXML Attribute\nandroid:textOn\nUsed to change the text to be displayed when the button is On. By default text is \u201cON\u201d\nandroid:textOff\nUsed to change the text to be displayed when the button is Off. By default text is \u201cOFF\u201d\nandroid:disabledAlpha\nThe alpha to apply to the indicator when disabled.\nNavigate res>layout>activity_main.xml:ges the state of the button\nIn this step, open the XML file and add the code to display the toggle button and a textview.acticity_main.xml\n Step 3: Using Methods Associated with the ToggleButtonWe will update the methods to test the full ability of out Togglebutton.\nMethod\nDescription\nCharSquence getTextOn()\nReturns the text when button is On\nCharSquence getTextOff()\nReturns the text when button is Off\nvoid setChecked(boolean checked)\nChanges the state of the button\nNavigate Open the app -> Java -> Package -> Mainactivity.java\nIn this step, open MainActivity and add the below code to initialize the toggle button and add onToggleClick method which will be invoked when the user clicks on the toggle button. This method changes the text in textview. MainActivity.javaimport android.os.Bundle;\nimport android.view.View;\nimport android.widget.TextView;\nimport android.widget.ToggleButton;\nimport androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity { ToggleButton togglebutton;\n TextView textview; @Override\n protected void onCreate(Bundle savedInstanceState) {\n super.onCreate(savedInstanceState);\n setContentView(R.layout.activity_main); // Initialize the toggle button and text view\n togglebutton = (ToggleButton) findViewById(R.id.toggleButton);\n textview = (TextView) findViewById(R.id.textView);\n } // Method is called when the toggle button is clicked\n public void onToggleClick(View view) {\n if (togglebutton.isChecked()) {\n textview.setText(\"Toggle is ON\");\n } else {\n textview.setText(\"Toggle is OFF\");\n }\n }\n}MainActivity.ktpackage com.gfg.toggle_buttonimport android.os.Bundle\nimport android.view.View\nimport android.widget.TextView\nimport android.widget.ToggleButton\nimport androidx.activity.enableEdgeToEdge\nimport androidx.appcompat.app.AppCompatActivity\nimport androidx.core.view.ViewCompat\nimport androidx.core.view.WindowInsetsCompatclass MainActivity : AppCompatActivity() {\n lateinit var toggleButton: ToggleButton\n lateinit var textView: TextView\n \n override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_main) // Initialize the toggle button and text view\n toggleButton = findViewById(R.id.button_toggle)\n textView = findViewById(R.id.textView1) } // Method is called when the toggle button is clicked\n fun onToggleClick(view: View) {\n if (toggleButton.isChecked) {\n textView.text = \"Toggle is ON\"\n } else {\n textView.text = \"Toggle is OFF\"\n }\n }\n}Output:\nNow connect your device with USB cable and launch the application. You will see a toggle button. Click on the toggle button which will display the status of the toggle button.The Final Application Created Can be downloaded from this link \u2013GitHub Link for the Toggle Key in Android Application",
"input": "",
"output": "using Volley LibraryJSON is also known as (JavaScript Object Notation) is a format to exchange the data from the server. The data stored in JSON format is lightweight and easy to handle. With the help of JSON, we can access the data in the form of JsonArray, JsonObject, and JsonStringer. In this article, we will specifically take a look at the implementation of JsonObject using Volley in Android.JSON Object: Json Object can be easily identified with \u201c{\u201d braces opening and \u201c}\u201d braces closing. We can fetch data from JSON objects with their key value. From that key, we can access the value of that key. What we are going to build in this article?\nWe will be building a simple application in which we will be displaying a simple CardView in which we will display a single course that is available on Geeks for Geeks. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.https://media.geeksforgeeks.org/wp-content/uploads/20210121214223/Screenrecorder-2021-01-21-21-39-44-445.mp4\nBelow is the JSON object from which we will be displaying the data in our Android App.{\n \u201ccourseName\u201d:\u201dFork CPP\u201d,\n \u201ccourseimg\u201d:\u201dhttps://media.geeksforgeeks.org/img-practice/banner/fork-cpp-thumbnail.png\u201d,\n \u201ccourseMode\u201d:\u201dOnline Batch\u201d,\n \u201ccourseTracks\u201d:\u201d6 Tracks\u201d\n}Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add the below dependency in your build.gradle file\nBelow is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. We have used the Picasso dependency for image loading from the URL. // below line is used for volley library\nimplementation \u2018com.android.volley:volley:1.1.1\u2019\n// below line is used for image loading library\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019After adding this dependency sync your project and now move towards the AndroidManifest.xml part. \nStep 3: Adding permissions to the internet in the AndroidManifest.xml file\nNavigate to the app > AndroidManifest.xml and add the below code to it.XML \nStep 4: Working with the activity_main.xml file\nNavigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.XML \n () { \n@Override\npublic void onResponse(JSONObject response) { \n// inside the on response method. \n// we are hiding our progress bar. \nloadingPB.setVisibility(View.GONE); // in below line we are making our card \n// view visible after we get all the data. \ncourseCV.setVisibility(View.VISIBLE); \ntry { \n// now we get our response from API in json object format. \n// in below line we are extracting a string with its key \n// value from our json object. \n// similarly we are extracting all the strings from our json object. \nString courseName = response.getString(\"courseName\"); \nString courseTracks = response.getString(\"courseTracks\"); \nString courseMode = response.getString(\"courseMode\"); \nString courseImageURL = response.getString(\"courseimg\"); // after extracting all the data we are \n// setting that data to all our views. \ncourseNameTV.setText(courseName); \ncourseTracksTV.setText(courseTracks); \ncourseBatchTV.setText(courseMode); // we are using picasso to load the image from url. \nPicasso.get().load(courseImageURL).into(courseIV); \n} catch (JSONException e) { \n// if we do not extract data from json object properly. \n// below line of code is use to handle json exception \ne.printStackTrace(); \n} \n} \n}, new Response.ErrorListener() { \n// this is the error listener method which \n// we will call if we get any error from API. \n@Override\npublic void onErrorResponse(VolleyError error) { \n// below line is use to display a toast message along with our error. \nToast.makeText(MainActivity.this, \"Fail to get data..\", Toast.LENGTH_SHORT).show(); \n} \n}); \n// at last we are adding our json \n// object request to our request \n// queue to fetch all the json data. \nqueue.add(jsonObjectRequest); \n} \n}Now run your app and see the output of the app.\nOutput:\nhttps://media.geeksforgeeks.org/wp-content/uploads/20210121214223/Screenrecorder-2021-01-21-21-39-44-445.mp4"
},
{
"instruction": "using Volley LibraryJSON is also known as (JavaScript Object Notation) is a format to exchange the data from the server. The data stored in JSON format is lightweight and easy to handle. With the help of JSON, we can access the data in the form of JsonArray, JsonObject, and JsonStringer. In this article, we will specifically take a look at the implementation of JsonObject using Volley in Android.JSON Object: Json Object can be easily identified with \u201c{\u201d braces opening and \u201c}\u201d braces closing. We can fetch data from JSON objects with their key value. From that key, we can access the value of that key. What we are going to build in this article?\nWe will be building a simple application in which we will be displaying a simple CardView in which we will display a single course that is available on Geeks for Geeks. A sample video is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.https://media.geeksforgeeks.org/wp-content/uploads/20210121214223/Screenrecorder-2021-01-21-21-39-44-445.mp4\nBelow is the JSON object from which we will be displaying the data in our Android App.{\n \u201ccourseName\u201d:\u201dFork CPP\u201d,\n \u201ccourseimg\u201d:\u201dhttps://media.geeksforgeeks.org/img-practice/banner/fork-cpp-thumbnail.png\u201d,\n \u201ccourseMode\u201d:\u201dOnline Batch\u201d,\n \u201ccourseTracks\u201d:\u201d6 Tracks\u201d\n}Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add the below dependency in your build.gradle file\nBelow is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. We have used the Picasso dependency for image loading from the URL. // below line is used for volley library\nimplementation \u2018com.android.volley:volley:1.1.1\u2019\n// below line is used for image loading library\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019After adding this dependency sync your project and now move towards the AndroidManifest.xml part. \nStep 3: Adding permissions to the internet in the AndroidManifest.xml file\nNavigate to the app > AndroidManifest.xml and add the below code to it.XML \nStep 4: Working with the activity_main.xml file\nNavigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.XML \n () { \n@Override\npublic void onResponse(JSONObject response) { \n// inside the on response method. \n// we are hiding our progress bar. \nloadingPB.setVisibility(View.GONE); // in below line we are making our card \n// view visible after we get all the data. \ncourseCV.setVisibility(View.VISIBLE); \ntry { \n// now we get our response from API in json object format. \n// in below line we are extracting a string with its key \n// value from our json object. \n// similarly we are extracting all the strings from our json object. \nString courseName = response.getString(\"courseName\"); \nString courseTracks = response.getString(\"courseTracks\"); \nString courseMode = response.getString(\"courseMode\"); \nString courseImageURL = response.getString(\"courseimg\"); // after extracting all the data we are \n// setting that data to all our views. \ncourseNameTV.setText(courseName); \ncourseTracksTV.setText(courseTracks); \ncourseBatchTV.setText(courseMode); // we are using picasso to load the image from url. \nPicasso.get().load(courseImageURL).into(courseIV); \n} catch (JSONException e) { \n// if we do not extract data from json object properly. \n// below line of code is use to handle json exception \ne.printStackTrace(); \n} \n} \n}, new Response.ErrorListener() { \n// this is the error listener method which \n// we will call if we get any error from API. \n@Override\npublic void onErrorResponse(VolleyError error) { \n// below line is use to display a toast message along with our error. \nToast.makeText(MainActivity.this, \"Fail to get data..\", Toast.LENGTH_SHORT).show(); \n} \n}); \n// at last we are adding our json \n// object request to our request \n// queue to fetch all the json data. \nqueue.add(jsonObjectRequest); \n} \n}Now run your app and see the output of the app.\nOutput:\nhttps://media.geeksforgeeks.org/wp-content/uploads/20210121214223/Screenrecorder-2021-01-21-21-39-44-445.mp4",
"input": "",
"output": "droid TextClock is a user interface control that is used to show the date/time in string format.\nIt provides time in two modes, the first one is to show the time in 24 Hour format and another one is to show the time in 12-hour format. We can easily use is24HourModeEnabled() method, to show the system using TextClock in 24 Hours or 12 Hours format.\nFirst, we create a new project by following the below steps:Click on File, then New => New Project.\nAfter that include the Kotlin support and click on next.\nSelect the minimum SDK as per convenience and click next button.\nThen select the Empty activity => next => finish.Different attributes for TextClock widgetXML attributes\nDescriptionandroid:id\nUsed to specify the id of the view.android:timeZone\nUsed to specify the zone for the time.android:format12Hour\nUsed for the 12 hour format.android:format24Hour\nUsed for the 24 hour format.android:text\nUsed to specify the text.android:textStyle\nUsed to specify the style of the text.android:textSize\nUsed to specify the size of the text.android:background\nUsed to set the background of the view.android:padding\nUsed to set the padding of the view.android:visibility\nUsed to set the visibility of the view.android:gravity\nUsed to specify the gravity of the view like center, top, bottom, etcModify activity_main.xml file\nIn this file, we use the TextClock, TextView, and Button and set attributes for all the widgets.XML \n\nUpdate strings.xml file\nHere, we update the name of the application using the string tag.XML \nTextClockInKotlin \n Access TextClock in MainActivity.kt file\nFirst, we declare two variables txtClock and txtView to access the widgets from the XML layout using the id.\nval txtClock = findViewById(R.id.txtClok)\n val txtView = findViewById(R.id.textview)\nthen, we access the button and set OnClickListener to display the time while clicking the button.\nval btn = findViewById(R.id.btn)\n btn?.setOnClickListener {\n txtView?.text = \"Time: \" + txtClock?.textKotlin package com.geeksforgeeks.myfirstKotlinappimport androidx.appcompat.app.AppCompatActivityimport android.os.Bundle\nimport android.widget.Button\nimport android.widget.TextClock\nimport android.widget.TextViewclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)val txtClock = findViewById(R.id.txtClok)\nval txtView = findViewById(R.id.textview)val btn = findViewById(R.id.btn)\nbtn?.setOnClickListener {\ntxtView?.text = \"Time: \" + txtClock?.text\n}\n}\n}AndroidManifest.xml fileKotlin \n\n\n\n \n \n \nUpdate strings.xml file\nHere, we update the name of the application using the string tag.XML \nTextClockInKotlin \n Access TextClock in MainActivity.kt file\nFirst, we declare two variables txtClock and txtView to access the widgets from the XML layout using the id.\nval txtClock = findViewById(R.id.txtClok)\n val txtView = findViewById(R.id.textview)\nthen, we access the button and set OnClickListener to display the time while clicking the button.\nval btn = findViewById(R.id.btn)\n btn?.setOnClickListener {\n txtView?.text = \"Time: \" + txtClock?.textKotlin package com.geeksforgeeks.myfirstKotlinappimport androidx.appcompat.app.AppCompatActivityimport android.os.Bundle\nimport android.widget.Button\nimport android.widget.TextClock\nimport android.widget.TextViewclass MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) {\nsuper.onCreate(savedInstanceState)\nsetContentView(R.layout.activity_main)val txtClock = findViewById(R.id.txtClok)\nval txtView = findViewById(R.id.textview)val btn = findViewById(R.id.btn)\nbtn?.setOnClickListener {\ntxtView?.text = \"Time: \" + txtClock?.text\n}\n}\n}AndroidManifest.xml fileKotlin \n\n\n\n \n \n Step 3: Creating a new layout XML file\nCreating a new file named grid_layout.xml in the same folder as the activity_main.xml file. This Custom View will host an ImageView. The main reason to use custom adapters is to display complex views in the GridView or ListView instead of some simple text. The custom view is named grid_layout.xml with the LinearLayout as its root and a simple ImageView.XML \n Step 4: Creating a Custom Adapter class\nWill name this class MyBaseAdapter which will extend BaseAdapter class and inherit the methods shown above. The main method we need to walk through is the getView method.\n@Override\npublic View getView(int i, View view, ViewGroup viewGroup)\n {\n if (view == null) {\n LayoutInflater inflater\n = (LayoutInflater)c.getSystemService(\nContext.LAYOUT_INFLATER_SERVICE);\n view = inflater.inflate(R.layout.grid_layout,\n viewGroup);\n }\n \n ImageView imageView = view.findViewById(R.id.imageView);\n imageView.setImageResource(items[i]);\n return view;\n}\nThe LayoutInflator is what is responsible for parsing our custom grid_layout.xml file. do note that this operation is expensive and should only be performed when needed. hence its place inside an if statement. Finally, we get a reference to the layout and store it in the view variable. then using that we can initialize the image view and set the image and return the view. In this example, the view shown is quite simple but we can have a more complete view like displaying the id of a person who can have a custom view of the Image, TextView, etc. The entire code of the MyBaseAdapter is given below.Java import android.content.Context; \nimport android.view.LayoutInflater; \nimport android.view.View; \nimport android.view.ViewGroup; \nimport android.widget.BaseAdapter; \nimport android.widget.ImageView; public class MyBaseAdapter extends BaseAdapter { \nContext c; \nint items[]; MyBaseAdapter(Context c, int arr[]) { \nthis.c = c; \nitems = arr; \n} @Override public int getCount() { return items.length; } @Override public Object getItem(int i) { return null; } @Override public long getItemId(int i) { return 0; } @Override\npublic View getView(int i, View view,ViewGroup viewGroup) { \nif (view == null) { \nLayoutInflater inflater = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE); \nview = inflater.inflate(R.layout.grid_layout, null); \n} \nImageView imageView = view.findViewById(R.id.imageView); \nimageView.setImageResource(items[i]); \nreturn view; \n} \n}Kotlin import android.content.Context \nimport android.view.View \nimport android.view.ViewGroup \nimport android.widget.BaseAdapter \nimport android.widget.ImageView class MyBaseAdapter internal constructor(var c: Context, var items: IntArray) : \nBaseAdapter() { \noverride fun getCount(): Int { \nreturn items.size \n} override fun getItem(i: Int): Any? { \nreturn null\n} override fun getItemId(i: Int): Long { \nreturn 0\n} override fun getView(i: Int, view: View, viewGroup: ViewGroup): View { \nval view = view \nval imageView = view.findViewById(R.id.imageView) \nimageView.setImageResource(items[i]) \nreturn view \n} \n}Step 5: Working with the MainActivity file\nThe data will use using images of different android studio logos saved in the drawable folder.To use these images we need to store them in an array and pass it to the custom adapter.\nJava:\nint[] itemsarray = new int[] {\n R.drawable.android_1, R.drawable.android_2,\n R.drawable.android_3, R.drawable.android_4,\n R.drawable.android_5, R.drawable.android_1,\n R.drawable.android_2, R.drawable.android_3,\n R.drawable.android_4, R.drawable.android_5\n};Kotlin:\nvar itemsarray = intArrayOf(\n R.drawable.android_1, R.drawable.android_2,\n R.drawable.android_3, R.drawable.android_4,\n R.drawable.android_5, R.drawable.android_1,\n R.drawable.android_2, R.drawable.android_3,\n R.drawable.android_4, R.drawable.android_5\n)\nNotice that the same 5 images are repeated. Now setting up the custom base adapter in the MainActivity file.\nGridView gridView = findViewById(R.id.grid_view);// create a object of myBaseAdapter\nMyBaseAdapter baseAdapter = new MyBaseAdapter(this, itemsarray);\ngridView.setAdapter(baseAdapter);\nFirst, we get a reference of the grid layout from the XML file using the fineViewById() method, then we create the object of myBaseAdapter which takes two arguments Context, and the items array. Finally, we set the adapter. Below is the complete code for theMainActivity file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.widget.GridView; \nimport androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { int[] itemsarray = new int[] { \nR.drawable.android_1, R.drawable.android_2, \nR.drawable.android_3, R.drawable.android_4, \nR.drawable.android_5, R.drawable.android_1, \nR.drawable.android_2, R.drawable.android_3, \nR.drawable.android_4, R.drawable.android_5 \n}; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); GridView gridView = findViewById(R.id.grid_view); // create a object of myBaseAdapter \nMyBaseAdapter baseAdapter = new MyBaseAdapter(this, itemsarray); \ngridView.setAdapter(baseAdapter); \n} \n}Kotlin import android.os.Bundle \nimport android.widget.GridView \nimport androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { \nvar itemsarray = intArrayOf( \nR.drawable.android_1, R.drawable.android_2, \nR.drawable.android_3, R.drawable.android_4, \nR.drawable.android_5, R.drawable.android_1, \nR.drawable.android_2, R.drawable.android_3, \nR.drawable.android_4, R.drawable.android_5 \n) override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) \nval gridView = findViewById(R.id.grid_view) // create a object of myBaseAdapter \nval baseAdapter = MyBaseAdapter(this, itemsarray) \ngridView.adapter = baseAdapter \n} \n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20201026151027/baseadapter.mp4"
},
{
"instruction": "er in Android with ExampleHere, we are designing an android app to demonstrate the use of GridView layout. The GridView layout is a ViewGroup that groups view in a two-dimensional scrolling grid of rows and columns. Items in the grid view are inserted using a ListAdapter. The layout by default is scrollable and we don\u2019t need to use ScrollView. An example of GridView is your default Gallery.\nAttributes of a GridViewAttributesDescriptionid\nLike all other views, android uses the id element to uniquely identify an element.numColumns\nThe number of columns to display. It can be an integer or auto_fit which will display as many possible columns to fill the screen of the device. If they don\u2019t specify this attribute then the grid view will behave like a listview.horizontalSpacing\nhorizontalSpacing property is used to define the default horizontal spacing between columns. This could be in pixel(px), density pixel(dp), or scale-independent pixel(sp).verticalSpacing\nThe vertical spacing property is used to define the default vertical spacing between rows. This should be in px, dp or sp.GridView Example Using Different Adapters in Android\nAn Adapter is a connection between the UI components(TextView, ImageView) and the data source. An adapter helps fill the UI element with the appropriate data. In android commonly used adapters that fill data in GridView are:ArrayAdapter\nBaseAdapter\nCustom ArrayAdapterThis tutorial will be using the BaseAdapter, following is the structure of the class that extends the base adapter.Java public class MyAdapter extends BaseAdapter { \n@Override public int getCount() { \nreturn 0; \n} @Override public Object getItem(int i) { \nreturn null; \n} @Override public long getItemId(int i) { \nreturn 0; \n} @Override\npublic View getView(int i, View view, ViewGroup viewGroup) { \nreturn null; \n} \n}Method Description:getCount(): this method returns the count of the total elements to be displayed.\ngetItem(int i): this method takes in an index and returns an object.\ngetItemId(int i): this method takes in an index and returns the id of the item being displayed in the GridView.\ngetView(int I, View view, ViewGroup group): this is the most important method which returns a view that is displayed in the grid view. The int i is the index, the view can be (ImageView or TextView), and the view group is the container that hosts the View e.g LinearLayout, RelativeLayout, etc.Example\nA sample GIF is given below to get an idea about what we are going to do in this article.Note that we are going toimplement this application in both Java and Kotlin Programming Languages for Android.Step By Step Implementation\nStep 1: Create a New Project in Android Studio\nTo create a new project in Android Studio please refer toHow to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android.\nStep 2: Working with the activity_main.xml file\nOpen the activity_main.xml file and insert a GridView component in it.The Layout will look blank initially but will be inflated by the custom adapter class during runtime.XML \n Step 3: Creating a new layout XML file\nCreating a new file named grid_layout.xml in the same folder as the activity_main.xml file. This Custom View will host an ImageView. The main reason to use custom adapters is to display complex views in the GridView or ListView instead of some simple text. The custom view is named grid_layout.xml with the LinearLayout as its root and a simple ImageView.XML \n Step 4: Creating a Custom Adapter class\nWill name this class MyBaseAdapter which will extend BaseAdapter class and inherit the methods shown above. The main method we need to walk through is the getView method.\n@Override\npublic View getView(int i, View view, ViewGroup viewGroup)\n {\n if (view == null) {\n LayoutInflater inflater\n = (LayoutInflater)c.getSystemService(\nContext.LAYOUT_INFLATER_SERVICE);\n view = inflater.inflate(R.layout.grid_layout,\n viewGroup);\n }\n \n ImageView imageView = view.findViewById(R.id.imageView);\n imageView.setImageResource(items[i]);\n return view;\n}\nThe LayoutInflator is what is responsible for parsing our custom grid_layout.xml file. do note that this operation is expensive and should only be performed when needed. hence its place inside an if statement. Finally, we get a reference to the layout and store it in the view variable. then using that we can initialize the image view and set the image and return the view. In this example, the view shown is quite simple but we can have a more complete view like displaying the id of a person who can have a custom view of the Image, TextView, etc. The entire code of the MyBaseAdapter is given below.Java import android.content.Context; \nimport android.view.LayoutInflater; \nimport android.view.View; \nimport android.view.ViewGroup; \nimport android.widget.BaseAdapter; \nimport android.widget.ImageView; public class MyBaseAdapter extends BaseAdapter { \nContext c; \nint items[]; MyBaseAdapter(Context c, int arr[]) { \nthis.c = c; \nitems = arr; \n} @Override public int getCount() { return items.length; } @Override public Object getItem(int i) { return null; } @Override public long getItemId(int i) { return 0; } @Override\npublic View getView(int i, View view,ViewGroup viewGroup) { \nif (view == null) { \nLayoutInflater inflater = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE); \nview = inflater.inflate(R.layout.grid_layout, null); \n} \nImageView imageView = view.findViewById(R.id.imageView); \nimageView.setImageResource(items[i]); \nreturn view; \n} \n}Kotlin import android.content.Context \nimport android.view.View \nimport android.view.ViewGroup \nimport android.widget.BaseAdapter \nimport android.widget.ImageView class MyBaseAdapter internal constructor(var c: Context, var items: IntArray) : \nBaseAdapter() { \noverride fun getCount(): Int { \nreturn items.size \n} override fun getItem(i: Int): Any? { \nreturn null\n} override fun getItemId(i: Int): Long { \nreturn 0\n} override fun getView(i: Int, view: View, viewGroup: ViewGroup): View { \nval view = view \nval imageView = view.findViewById(R.id.imageView) \nimageView.setImageResource(items[i]) \nreturn view \n} \n}Step 5: Working with the MainActivity file\nThe data will use using images of different android studio logos saved in the drawable folder.To use these images we need to store them in an array and pass it to the custom adapter.\nJava:\nint[] itemsarray = new int[] {\n R.drawable.android_1, R.drawable.android_2,\n R.drawable.android_3, R.drawable.android_4,\n R.drawable.android_5, R.drawable.android_1,\n R.drawable.android_2, R.drawable.android_3,\n R.drawable.android_4, R.drawable.android_5\n};Kotlin:\nvar itemsarray = intArrayOf(\n R.drawable.android_1, R.drawable.android_2,\n R.drawable.android_3, R.drawable.android_4,\n R.drawable.android_5, R.drawable.android_1,\n R.drawable.android_2, R.drawable.android_3,\n R.drawable.android_4, R.drawable.android_5\n)\nNotice that the same 5 images are repeated. Now setting up the custom base adapter in the MainActivity file.\nGridView gridView = findViewById(R.id.grid_view);// create a object of myBaseAdapter\nMyBaseAdapter baseAdapter = new MyBaseAdapter(this, itemsarray);\ngridView.setAdapter(baseAdapter);\nFirst, we get a reference of the grid layout from the XML file using the fineViewById() method, then we create the object of myBaseAdapter which takes two arguments Context, and the items array. Finally, we set the adapter. Below is the complete code for theMainActivity file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.widget.GridView; \nimport androidx.appcompat.app.AppCompatActivity; public class MainActivity extends AppCompatActivity { int[] itemsarray = new int[] { \nR.drawable.android_1, R.drawable.android_2, \nR.drawable.android_3, R.drawable.android_4, \nR.drawable.android_5, R.drawable.android_1, \nR.drawable.android_2, R.drawable.android_3, \nR.drawable.android_4, R.drawable.android_5 \n}; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); GridView gridView = findViewById(R.id.grid_view); // create a object of myBaseAdapter \nMyBaseAdapter baseAdapter = new MyBaseAdapter(this, itemsarray); \ngridView.setAdapter(baseAdapter); \n} \n}Kotlin import android.os.Bundle \nimport android.widget.GridView \nimport androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() { \nvar itemsarray = intArrayOf( \nR.drawable.android_1, R.drawable.android_2, \nR.drawable.android_3, R.drawable.android_4, \nR.drawable.android_5, R.drawable.android_1, \nR.drawable.android_2, R.drawable.android_3, \nR.drawable.android_4, R.drawable.android_5 \n) override fun onCreate(savedInstanceState: Bundle?) { \nsuper.onCreate(savedInstanceState) \nsetContentView(R.layout.activity_main) \nval gridView = findViewById(R.id.grid_view) // create a object of myBaseAdapter \nval baseAdapter = MyBaseAdapter(this, itemsarray) \ngridView.adapter = baseAdapter \n} \n}Output:https://media.geeksforgeeks.org/wp-content/uploads/20201026151027/baseadapter.mp4",
"input": "",
"output": "se with Operations in Android with ExamplesFirebase Realtime Database is a Cloud hosted database, i.e. it runs on a cloud and access to the user is provided as a service. It stores data in JSON (Javascript Object Notation) format, a format to store or transport data. All the users connected to it can get access to the data at Real Time.Features of Firebase Realtime Database?Real Time: Due to the Data synchronization used in Real Time, every update is received by the devices/clients in no time.No need of Application Server: As the database can be accessed directly from the mobile device or browser there is no need for an Application Server.Support by various languages and platforms:Splitting Data: The client can split the data across multiple database instances for the same project.Client-Side Code: The dynamic applications with the secured data can be accessed directly from the client-side code.Cross-Platform: It can be used for building a back-end for various platforms like Android, iOS, Web, iOS as well as JavaScript SDK.Structuring the Realtime Database:\nFirebase Realtime Database stores data as one large JSON tree. It stores simple data easily, but the unstructured hierarchical data is difficult to organize. Unlike SQL there are no tables here.What is JSON Tree Model?\nJSON Tree Model is inspired from JSON( JavaScript Object Notation) used to represent the JSON document which generally consists of key-value pair in memory .Why to structure the data (What are the advantages of doing it)?If data is stored in well formatted structure then it is easy to save as well as retrieve it easily.Querying becomes easy on the structured data.It becomes feasible to refer the data in structured format.Key points to remember while structuring the data:\nBefore writing and reading the data into the database, the main aim of the developer should be constructing the structure of the database.Consider the Nesting Limit:\nThe Nesting of the data should be done in a proper way such that it should be easy to read it using Listeners(Listeners are used to reading the data from the database). Avoid unnecessary nesting of levels in the database. Firebase also allows only 32 levels of Nesting.\nFor Example:// JSON Format Structuring Simple Example\n{\n\"userinfo\":\n {\n \"a\":\n {\n \"name\": \"GfG1\",\n \"address\":\"GeeksForGeeksOne\",\n \"order_details\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"5\",\n \"price\":\"500\",\n \"address_of_delivery\":\"xyz, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"10\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"xyz2, abc, ...\"\n } }\n }, \"b\":\n {\n \"name\": \"GfG2\",\n \"address\":\"GeeksForGeeksTwo\",\n \"order_details\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"12\",\n \"price\":\"1500\",\n \"address_of_delivery\":\"pqr, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"18\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"pqr2, abc, ...\"\n } }\n }\n }\n}In this example, retrieving the data of names of users is very difficult as we have to access the child nodes of users_info which downloads the data having several MB\u2019s sizes (in this case name, orders_details, address, etc gets downloaded). Design a Denormalized form of Data:\nThe Flattening of the data should be done correctly, means that data should be split into different parts without any ambiguity. This is generally referred to as denormalisation, where in order to improve read performance we develop redundancy in the data. \nFor Example: // JSON Format Example with Denormalized form for example in Point 1\n{\n \"user_info\":\n {\n \"a\": \n {\n \"name\": \"GfG1\",\n \"address\":\"GeeksForGeeksOne\" \n }, \"b\":\n {\n \"name\": \"GfG2\",\n \"address\":\"GeeksForGeeksTwo\"\n } \n },\n \"order_details\":\n {\n \"a\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"5\",\n \"price\":\"500\",\n \"address_of_delivery\":\"xyz, abc, ...\"\n }, \n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"10\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"xyz2, abc, ...\"\n } \n },\n \"b\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"12\",\n \"price\":\"1500\",\n \"address_of_delivery\":\"pqr, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"18\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"pqr2, abc, ...\"\n } } \n }}In this example, the data is split as user_info and order_deatils. Due to this, the accessibility of the data is faster and hence, no need to download the oversized unnecessary data. Here, Retrieving the data of names of users is very simple as we have to access the child nodes of users_info which downloads the data having a name and address details only and no details of orders are processed. Create a structure which is Dynamic in Nature:\nThe structuring of the data should be such that it should be scalable. Sometimes in order to have easy accessibility of the data, duplication needs to be implemented in the database.\nFor Example: // JSON Format Example explaining the Scaling property\n{\n \"student_info\":\n {\n \"1\":\n {\n \"name\":\"GfG1\",\n \"roll_no\":\"1\",\n \"exam_board\":\"abc\" \n }, \"2\":\n {\n \"name\":\"GfG2\",\n \"roll_no\":\"2\",\n \"exam_board\":\"pqr\" \n },\n \n \"3\":\n {\n \"name\":\"GfG3\",\n \"roll_no\":\"3\",\n \"exam_board\":\"abc\" \n }\n },\n \n \"board_info\":\n {\n \"abc\":\n { \n \"student_names\":\n {\n \"GfG1\":true,\n \"GfG2\":false,\n \"GfG3\":true \n } \n },\n \n \"pqr\":\n { \n \"student_names\":\n {\n \"GfG1\":false,\n \"GfG2\":true,\n \"GfG3\":false \n } \n }\n }}In the above example, in order to access the database easily, the name of the board is stored in every students information as well as the board information stores the name of the student and the board he is having. If we had not stored the data under board information, then it would be difficult to collect the names of students having a particular board.Writing/Inserting data into Firebase Realtime Database\nWriting the data to the Firebase is a very easy task. But before writing / inserting the data to the Realtime database the Structuring of the data should be done. Inserting or writing the data to the Firebase Realtime database is done in Android using the function setValue(). Inserting the data to the Firebase Realtime database can be considered as one of the CRUD operations.\nsetValue(): This function is used to: Replace the data at the referenced position \nIf no data present at the referenced position then it writes the data directly at that positionThe value/types that can be passed to it are:String\nMap\nList\nDouble\nBoolean\nLong\nUser-defined Object: Here, it should be considered that the user-defined object having default constructor can also be passed as the argument to the function. Steps for Writing/Inserting data into Firebase Realtime Database:\nConsider that we have to store the name of the user to the database Create a Database Reference:// Consider that we have to store\n// this in the databaseString name = \"GfG1\" ; Find the reference of the data where the value is to be stored using the child() function:// Create an object of Firebase Database ReferenceDatabaseReference reference;\nreference = FirebaseDatabase.getInstance().getReference(); Use the referenced object and setValue() function with the value to be stored as an argument to it in order to write the data://Inserts the data to the databasereference.child(\"user\").setValue(name); Output:Example 2: Let us consider another example to store the user-defined object to the database STEP 1:// Create a class Userclass User\n{\n String name;\n String address; User()\n {\n name = \"\";\n address = \"\";\n }\n \n User(String name, String address)\n {\n this.name = name;\n this.address = address;\n }} STEP 2:// Create a user-defined objectUser user1 = new User(\"GfG1\", \"GeeksForGeeks\");STEP 3:// Create an object of Firebase Database ReferenceDatabaseReference reference ;\nreference = FirebaseDatabase.getInstance().getReference(); // Insert the user-defined object to the database reference.child(\"user\").setValue(user1); Output:"
},
{
"instruction": "se with Operations in Android with ExamplesFirebase Realtime Database is a Cloud hosted database, i.e. it runs on a cloud and access to the user is provided as a service. It stores data in JSON (Javascript Object Notation) format, a format to store or transport data. All the users connected to it can get access to the data at Real Time.Features of Firebase Realtime Database?Real Time: Due to the Data synchronization used in Real Time, every update is received by the devices/clients in no time.No need of Application Server: As the database can be accessed directly from the mobile device or browser there is no need for an Application Server.Support by various languages and platforms:Splitting Data: The client can split the data across multiple database instances for the same project.Client-Side Code: The dynamic applications with the secured data can be accessed directly from the client-side code.Cross-Platform: It can be used for building a back-end for various platforms like Android, iOS, Web, iOS as well as JavaScript SDK.Structuring the Realtime Database:\nFirebase Realtime Database stores data as one large JSON tree. It stores simple data easily, but the unstructured hierarchical data is difficult to organize. Unlike SQL there are no tables here.What is JSON Tree Model?\nJSON Tree Model is inspired from JSON( JavaScript Object Notation) used to represent the JSON document which generally consists of key-value pair in memory .Why to structure the data (What are the advantages of doing it)?If data is stored in well formatted structure then it is easy to save as well as retrieve it easily.Querying becomes easy on the structured data.It becomes feasible to refer the data in structured format.Key points to remember while structuring the data:\nBefore writing and reading the data into the database, the main aim of the developer should be constructing the structure of the database.Consider the Nesting Limit:\nThe Nesting of the data should be done in a proper way such that it should be easy to read it using Listeners(Listeners are used to reading the data from the database). Avoid unnecessary nesting of levels in the database. Firebase also allows only 32 levels of Nesting.\nFor Example:// JSON Format Structuring Simple Example\n{\n\"userinfo\":\n {\n \"a\":\n {\n \"name\": \"GfG1\",\n \"address\":\"GeeksForGeeksOne\",\n \"order_details\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"5\",\n \"price\":\"500\",\n \"address_of_delivery\":\"xyz, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"10\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"xyz2, abc, ...\"\n } }\n }, \"b\":\n {\n \"name\": \"GfG2\",\n \"address\":\"GeeksForGeeksTwo\",\n \"order_details\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"12\",\n \"price\":\"1500\",\n \"address_of_delivery\":\"pqr, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"18\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"pqr2, abc, ...\"\n } }\n }\n }\n}In this example, retrieving the data of names of users is very difficult as we have to access the child nodes of users_info which downloads the data having several MB\u2019s sizes (in this case name, orders_details, address, etc gets downloaded). Design a Denormalized form of Data:\nThe Flattening of the data should be done correctly, means that data should be split into different parts without any ambiguity. This is generally referred to as denormalisation, where in order to improve read performance we develop redundancy in the data. \nFor Example: // JSON Format Example with Denormalized form for example in Point 1\n{\n \"user_info\":\n {\n \"a\": \n {\n \"name\": \"GfG1\",\n \"address\":\"GeeksForGeeksOne\" \n }, \"b\":\n {\n \"name\": \"GfG2\",\n \"address\":\"GeeksForGeeksTwo\"\n } \n },\n \"order_details\":\n {\n \"a\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"5\",\n \"price\":\"500\",\n \"address_of_delivery\":\"xyz, abc, ...\"\n }, \n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"10\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"xyz2, abc, ...\"\n } \n },\n \"b\":\n {\n \"p1\":\n {\n \"product_id\":\"1\",\n \"quantity\":\"12\",\n \"price\":\"1500\",\n \"address_of_delivery\":\"pqr, abc, ...\"\n },\n \n \"p2\":\n {\n \"product_id\":\"2\",\n \"quantity\":\"18\",\n \"price\":\"1000\",\n \"address_of_delivery\":\"pqr2, abc, ...\"\n } } \n }}In this example, the data is split as user_info and order_deatils. Due to this, the accessibility of the data is faster and hence, no need to download the oversized unnecessary data. Here, Retrieving the data of names of users is very simple as we have to access the child nodes of users_info which downloads the data having a name and address details only and no details of orders are processed. Create a structure which is Dynamic in Nature:\nThe structuring of the data should be such that it should be scalable. Sometimes in order to have easy accessibility of the data, duplication needs to be implemented in the database.\nFor Example: // JSON Format Example explaining the Scaling property\n{\n \"student_info\":\n {\n \"1\":\n {\n \"name\":\"GfG1\",\n \"roll_no\":\"1\",\n \"exam_board\":\"abc\" \n }, \"2\":\n {\n \"name\":\"GfG2\",\n \"roll_no\":\"2\",\n \"exam_board\":\"pqr\" \n },\n \n \"3\":\n {\n \"name\":\"GfG3\",\n \"roll_no\":\"3\",\n \"exam_board\":\"abc\" \n }\n },\n \n \"board_info\":\n {\n \"abc\":\n { \n \"student_names\":\n {\n \"GfG1\":true,\n \"GfG2\":false,\n \"GfG3\":true \n } \n },\n \n \"pqr\":\n { \n \"student_names\":\n {\n \"GfG1\":false,\n \"GfG2\":true,\n \"GfG3\":false \n } \n }\n }}In the above example, in order to access the database easily, the name of the board is stored in every students information as well as the board information stores the name of the student and the board he is having. If we had not stored the data under board information, then it would be difficult to collect the names of students having a particular board.Writing/Inserting data into Firebase Realtime Database\nWriting the data to the Firebase is a very easy task. But before writing / inserting the data to the Realtime database the Structuring of the data should be done. Inserting or writing the data to the Firebase Realtime database is done in Android using the function setValue(). Inserting the data to the Firebase Realtime database can be considered as one of the CRUD operations.\nsetValue(): This function is used to: Replace the data at the referenced position \nIf no data present at the referenced position then it writes the data directly at that positionThe value/types that can be passed to it are:String\nMap\nList\nDouble\nBoolean\nLong\nUser-defined Object: Here, it should be considered that the user-defined object having default constructor can also be passed as the argument to the function. Steps for Writing/Inserting data into Firebase Realtime Database:\nConsider that we have to store the name of the user to the database Create a Database Reference:// Consider that we have to store\n// this in the databaseString name = \"GfG1\" ; Find the reference of the data where the value is to be stored using the child() function:// Create an object of Firebase Database ReferenceDatabaseReference reference;\nreference = FirebaseDatabase.getInstance().getReference(); Use the referenced object and setValue() function with the value to be stored as an argument to it in order to write the data://Inserts the data to the databasereference.child(\"user\").setValue(name); Output:Example 2: Let us consider another example to store the user-defined object to the database STEP 1:// Create a class Userclass User\n{\n String name;\n String address; User()\n {\n name = \"\";\n address = \"\";\n }\n \n User(String name, String address)\n {\n this.name = name;\n this.address = address;\n }} STEP 2:// Create a user-defined objectUser user1 = new User(\"GfG1\", \"GeeksForGeeks\");STEP 3:// Create an object of Firebase Database ReferenceDatabaseReference reference ;\nreference = FirebaseDatabase.getInstance().getReference(); // Insert the user-defined object to the database reference.child(\"user\").setValue(user1); Output:",
"input": "",
"output": "F Viewer in Android with Firebase?If you are creating apps for students or for educational purposes then you need to add some PDF files for displaying some data inside our app. These PDF files are updated on regular basis. For loading this PDF from the server we prefer to use PDF Viewer which will load the PDF from the URL in Android. Inside this, we add the URL for PDF inside our Apps code and load it from that URL. What if we want to change that PDF, so for that we need to change the URL of the PDF inside our code. But practically it will not be possible to change the URL for PDF files and update the app for users. So for handling this case we will use Firebase. By using Firebase we will dynamically load PDF from Firebase and update the PDF inside our app. Now we will move towards the implementation part.\nWhat we are going to build in this project?\nWe will be building an application in which we will be loading PDF from our Firebase Console and update that PDF in Realtime by changing the URL in our Firebase Console. For the implementation of this project, we will be using Firebase Realtime Database with which we will be updating our PDF in Realtime. Note that we are going toimplement this project using theJavalanguage.\nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Connect your app to Firebase\nAfter creating a new project. Navigate to the Tools option on the top bar. Inside that click on Firebase. After clicking on Firebase, you can get to see the right column mentioned below in the screenshot. Inside that column Navigate to Firebase Realtime Database. Click on that option and you will get to see two options on Connect app to Firebase and Add Firebase Realtime Database to your app. Click on Connect now and your app will be connected to Firebase. After that click on the second option and now your App is connected to Firebase. After completing this process you will get to see the below screen. Now verify that your app is connected to Firebase or not. Go to your build.gradle file. Navigate to the app > Gradle Scripts > build.gradle file and make sure that the below dependency is added in your dependencies section.implementation \u2018com.google.firebase:firebase-database:19.6.0\u2019After adding this dependency add the dependency of PDF Viewer in your Gradle file.\nStep 3: Add the dependency for PDF Viewer in build.gradle file\nNavigate to the app > Gradle Scripts > build.gradle file and add below dependency in it.implementation \u2018com.github.barteksc:android-pdf-viewer:2.8.2\u2019After adding this dependency sync your project. Now we will move towards our XML part.\nStep 4: Add internet permission in your AndroidManifest.xml file\nAdd the permission for the internet in the AndroidManifest.xml file.XML \n {\n// we are calling async task and performing \n// this task to load pdf in background.\n@Override\nprotected InputStream doInBackground(String... strings) {\n// below line is for declaring\n// our input stream.\nInputStream pdfStream = null;\ntry {\n// creating a new URL and passing \n// our string in it.\nURL url = new URL(strings[0]);// creating a new http url connection and calling open\n// connection method to open http url connection.\nHttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();\nif (httpURLConnection.getResponseCode() == 200) {\n// if the connection is successful then \n// we are getting response code as 200.\n// after the connection is successful \n// we are passing our pdf file from url\n// in our pdfstream.\npdfStream = new BufferedInputStream(httpURLConnection.getInputStream());\n}} catch (IOException e) {\n// this method is \n// called to handle errors.\nreturn null;\n}\n// returning our stream\n// of PDF file.\nreturn pdfStream;\n}@Override\nprotected void onPostExecute(InputStream inputStream) {\n// after loading stream we are setting \n// the pdf in your pdf view.\npdfView.fromStream(inputStream).load();\n}\n}\n}Step 7: Adding URL for PDF in your Firebase Console\nFor adding PDF URL in Firebase Console. Browse for Firebase in your browser and Click on Go to Console option in the top right corner as shown in the below screenshot.After clicking on Go to Console option you will get to see your project. Click on your project name from the available list of projects.After clicking on your project. Click on the Realtime Database option in the left window.After clicking on this option you will get to see the screen on the right side. On this page click on the Rules option which is present in the top bar. You will get to see the below screen. In this project, we are adding our rules as true for read as well as a write because we are not using any authentication to verify our user. So we are currently setting it to true to test our application. After changing your rules. Click on the publish button at the top right corner and your rules will be saved there. Now again come back to the Data tab. Now we will be adding our data to Firebase manually from Firebase itself.\nStep 8: Adding URL for your PDF in Firebase Console\nInside Firebase Realtime Database. Navigate to the Data tab. Inside this tab Hover on database section inside that click on the \u201c+\u201d icon. After clicking on the \u201c+\u201d icon you will get to see two input fields which are the Name and Value fields. Inside the Name field, you have to add a reference for your PDF file which in our case is \u201curl\u201d. And in our value field, we have to add a URL for our PDF file. After adding the value in this field. Click on the Add button and your data will be added to Firebase Console.After adding this PDF URL now run your app and see the OUTPUT of your app.\nOutput:\nYou can change the URL of the PDF and the PDF inside your app will be updated in Realtime without loading your app again.https://media.geeksforgeeks.org/wp-content/uploads/20210101132859/Screenrecorder-2021-01-01-13-27-16-504.mp4"
},
{
"instruction": "F Viewer in Android with Firebase?If you are creating apps for students or for educational purposes then you need to add some PDF files for displaying some data inside our app. These PDF files are updated on regular basis. For loading this PDF from the server we prefer to use PDF Viewer which will load the PDF from the URL in Android. Inside this, we add the URL for PDF inside our Apps code and load it from that URL. What if we want to change that PDF, so for that we need to change the URL of the PDF inside our code. But practically it will not be possible to change the URL for PDF files and update the app for users. So for handling this case we will use Firebase. By using Firebase we will dynamically load PDF from Firebase and update the PDF inside our app. Now we will move towards the implementation part.\nWhat we are going to build in this project?\nWe will be building an application in which we will be loading PDF from our Firebase Console and update that PDF in Realtime by changing the URL in our Firebase Console. For the implementation of this project, we will be using Firebase Realtime Database with which we will be updating our PDF in Realtime. Note that we are going toimplement this project using theJavalanguage.\nStep by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Connect your app to Firebase\nAfter creating a new project. Navigate to the Tools option on the top bar. Inside that click on Firebase. After clicking on Firebase, you can get to see the right column mentioned below in the screenshot. Inside that column Navigate to Firebase Realtime Database. Click on that option and you will get to see two options on Connect app to Firebase and Add Firebase Realtime Database to your app. Click on Connect now and your app will be connected to Firebase. After that click on the second option and now your App is connected to Firebase. After completing this process you will get to see the below screen. Now verify that your app is connected to Firebase or not. Go to your build.gradle file. Navigate to the app > Gradle Scripts > build.gradle file and make sure that the below dependency is added in your dependencies section.implementation \u2018com.google.firebase:firebase-database:19.6.0\u2019After adding this dependency add the dependency of PDF Viewer in your Gradle file.\nStep 3: Add the dependency for PDF Viewer in build.gradle file\nNavigate to the app > Gradle Scripts > build.gradle file and add below dependency in it.implementation \u2018com.github.barteksc:android-pdf-viewer:2.8.2\u2019After adding this dependency sync your project. Now we will move towards our XML part.\nStep 4: Add internet permission in your AndroidManifest.xml file\nAdd the permission for the internet in the AndroidManifest.xml file.XML \n {\n// we are calling async task and performing \n// this task to load pdf in background.\n@Override\nprotected InputStream doInBackground(String... strings) {\n// below line is for declaring\n// our input stream.\nInputStream pdfStream = null;\ntry {\n// creating a new URL and passing \n// our string in it.\nURL url = new URL(strings[0]);// creating a new http url connection and calling open\n// connection method to open http url connection.\nHttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();\nif (httpURLConnection.getResponseCode() == 200) {\n// if the connection is successful then \n// we are getting response code as 200.\n// after the connection is successful \n// we are passing our pdf file from url\n// in our pdfstream.\npdfStream = new BufferedInputStream(httpURLConnection.getInputStream());\n}} catch (IOException e) {\n// this method is \n// called to handle errors.\nreturn null;\n}\n// returning our stream\n// of PDF file.\nreturn pdfStream;\n}@Override\nprotected void onPostExecute(InputStream inputStream) {\n// after loading stream we are setting \n// the pdf in your pdf view.\npdfView.fromStream(inputStream).load();\n}\n}\n}Step 7: Adding URL for PDF in your Firebase Console\nFor adding PDF URL in Firebase Console. Browse for Firebase in your browser and Click on Go to Console option in the top right corner as shown in the below screenshot.After clicking on Go to Console option you will get to see your project. Click on your project name from the available list of projects.After clicking on your project. Click on the Realtime Database option in the left window.After clicking on this option you will get to see the screen on the right side. On this page click on the Rules option which is present in the top bar. You will get to see the below screen. In this project, we are adding our rules as true for read as well as a write because we are not using any authentication to verify our user. So we are currently setting it to true to test our application. After changing your rules. Click on the publish button at the top right corner and your rules will be saved there. Now again come back to the Data tab. Now we will be adding our data to Firebase manually from Firebase itself.\nStep 8: Adding URL for your PDF in Firebase Console\nInside Firebase Realtime Database. Navigate to the Data tab. Inside this tab Hover on database section inside that click on the \u201c+\u201d icon. After clicking on the \u201c+\u201d icon you will get to see two input fields which are the Name and Value fields. Inside the Name field, you have to add a reference for your PDF file which in our case is \u201curl\u201d. And in our value field, we have to add a URL for our PDF file. After adding the value in this field. Click on the Add button and your data will be added to Firebase Console.After adding this PDF URL now run your app and see the OUTPUT of your app.\nOutput:\nYou can change the URL of the PDF and the PDF inside your app will be updated in Realtime without loading your app again.https://media.geeksforgeeks.org/wp-content/uploads/20210101132859/Screenrecorder-2021-01-01-13-27-16-504.mp4",
"input": "",
"output": "ect in Android Studio Canary Version with Jetpack Compose?Jetpack Compose is a new toolkit provided by Google. This is useful for designing beautiful UI designs. After successful installation of the Android Studio Canary version, we are moving towards the creation of a new Project. In this article, we will take a look at How to create a new project in the Android Studio Canary Version using Jetpack Compose.\nCreate a New Project in Android Studio with Jetpack Compose\nAfter launching up your Android Studio Canary version for the first time you will get to see the below screen.\nStep 1: Click on the first option to start with New Project click on the Create New Project option after that you will get to see the below screen.Step 2: After clicking on Create New Project you will get to see the below screen.\nOn this screen make sure to select Phone and Tablet as a default selection and then click on Empty Compose Activity in the right section and then click on the Next option.Step 3: After selecting Empty Compose Activity you will get to see the below screen.\nAfter click on next, you will get to see the below screen. On this screen give a name to your application in the first text box which represents the Name of the project. Select your minimum SDK for Marshmallow (6.0). The 84.9% of devices indicates the % of devices on which our app will works. After giving the name and selecting the minimum SDK click on the Finish option to create a new project.After clicking on Finish the default application will be created and now you can start writing your code."
},
{
"instruction": "ect in Android Studio Canary Version with Jetpack Compose?Jetpack Compose is a new toolkit provided by Google. This is useful for designing beautiful UI designs. After successful installation of the Android Studio Canary version, we are moving towards the creation of a new Project. In this article, we will take a look at How to create a new project in the Android Studio Canary Version using Jetpack Compose.\nCreate a New Project in Android Studio with Jetpack Compose\nAfter launching up your Android Studio Canary version for the first time you will get to see the below screen.\nStep 1: Click on the first option to start with New Project click on the Create New Project option after that you will get to see the below screen.Step 2: After clicking on Create New Project you will get to see the below screen.\nOn this screen make sure to select Phone and Tablet as a default selection and then click on Empty Compose Activity in the right section and then click on the Next option.Step 3: After selecting Empty Compose Activity you will get to see the below screen.\nAfter click on next, you will get to see the below screen. On this screen give a name to your application in the first text box which represents the Name of the project. Select your minimum SDK for Marshmallow (6.0). The 84.9% of devices indicates the % of devices on which our app will works. After giving the name and selecting the minimum SDK click on the Finish option to create a new project.After clicking on Finish the default application will be created and now you can start writing your code.",
"input": "",
"output": "n Android with ExampleAndroid apps are growing and one important aspect of it is reusability. Sometimes, the complexity of app design will be more and during that time, Android providing very efficient reusable features by means of the (R.id.ButtonToInclude) as Button// get the reference of custom Layout's ImageView\ncustomImageView = findViewById(R.id.imageViewToInclude) as ImageView// We have clicked on Custom layout button, though it is in separate xml\n// because of include tag, it is getting focus here and we can do\n// activities as we like\ncustomButton!!.setOnClickListener { \nToast.makeText(applicationContext, \"We have clicked on Custom layout button\", Toast.LENGTH_LONG).show()\n}\n}\n}Running the Code on the EmulatorWe can able to get the output as attached in the video. Apply (R.id.ButtonToInclude) as Button// get the reference of custom Layout's ImageView\ncustomImageView = findViewById(R.id.imageViewToInclude) as ImageView// We have clicked on Custom layout button, though it is in separate xml\n// because of include tag, it is getting focus here and we can do\n// activities as we like\ncustomButton!!.setOnClickListener { \nToast.makeText(applicationContext, \"We have clicked on Custom layout button\", Toast.LENGTH_LONG).show()\n}\n}\n}Running the Code on the EmulatorWe can able to get the output as attached in the video. Apply \n \n { private ArrayList instaModalArrayList; \nprivate Context context; public InstagramFeedRVAdapter(ArrayList instaModalArrayList, Context context) { \nthis.instaModalArrayList = instaModalArrayList; \nthis.context = context; \n} @NonNull\n@Override\npublic InstagramFeedRVAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { \n// inflating our layout for item of recycler view item. \nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.insta_feed_rv_item, parent, false); \nreturn new InstagramFeedRVAdapter.ViewHolder(view); \n} @Override\npublic void onBindViewHolder(@NonNull InstagramFeedRVAdapter.ViewHolder holder, int position) { \nInstaModal modal = instaModalArrayList.get(position); \nholder.authorTV.setText(modal.getUsername()); \nif (modal.getMedia_type().equals(\"IMAGE\")) { \nPicasso.get().load(modal.getMedia_url()).into(holder.postIV); \n} \nholder.desctv.setText(modal.getCaption()); \nholder.likeTV.setText(\"\" + modal.getLikesCount() + \" likes\"); \nPicasso.get().load(modal.getAuthor_url()).into(holder.authorIV); \n} @Override\npublic int getItemCount() { \nreturn instaModalArrayList.size(); \n} public class ViewHolder extends RecyclerView.ViewHolder { CircleImageView authorIV; \nprivate TextView authorTV; \nprivate ImageView postIV; \nprivate TextView likeTV, desctv; public ViewHolder(@NonNull View itemView) { \nsuper(itemView); \nauthorIV = itemView.findViewById(R.id.idCVAuthor); \nauthorTV = itemView.findViewById(R.id.idTVAuthorName); \npostIV = itemView.findViewById(R.id.idIVPost); \nlikeTV = itemView.findViewById(R.id.idTVLikes); \ndesctv = itemView.findViewById(R.id.idTVPostDesc); \n} \n} \n}Step 9: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.view.View; \nimport android.widget.ProgressBar; \nimport android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; \nimport androidx.recyclerview.widget.LinearLayoutManager; \nimport androidx.recyclerview.widget.RecyclerView; import com.android.volley.Request; \nimport com.android.volley.RequestQueue; \nimport com.android.volley.Response; \nimport com.android.volley.VolleyError; \nimport com.android.volley.toolbox.JsonObjectRequest; \nimport com.android.volley.toolbox.Volley; import org.json.JSONArray; \nimport org.json.JSONException; \nimport org.json.JSONObject; import java.util.ArrayList; public class MainActivity extends AppCompatActivity { // creating variables for our requestqueue, \n// array list, progressbar, edittext, \n// image button and our recycler view. \nprivate RequestQueue mRequestQueue; \nprivate ArrayList instaModalArrayList; \nprivate ProgressBar progressBar; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // initializing our views. \nprogressBar = findViewById(R.id.idLoadingPB); \ninstaModalArrayList = new ArrayList<>(); // calling method to load \n// data in recycler view. \ngetInstagramData(); \n} private void getInstagramData() { \n// below line is use to initialize the variable for our request queue. \nmRequestQueue = Volley.newRequestQueue(MainActivity.this); // below line is use to clear cache this will \n// be use when our data is being updated. \nmRequestQueue.getCache().clear(); // below is the url for getting data \n// from API in json format. \nString url = \"Enter your URL\"; // below line we are creating a new request queue. \nRequestQueue queue = Volley.newRequestQueue(MainActivity.this); \nJsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener() { \n@Override\npublic void onResponse(JSONObject response) { \nprogressBar.setVisibility(View.GONE); \ntry { \nJSONArray dataArray = response.getJSONArray(\"data\"); \nfor (int i = 0; i < dataArray.length(); i++) { \n// below line is to extract data from JSON file. \nJSONObject dataObj = dataArray.getJSONObject(i); \nString id = dataObj.getString(\"id\"); \nString media_type = dataObj.getString(\"media_type\"); \nString permalink = dataObj.getString(\"permalink\"); \nString media_url = dataObj.getString(\"media_url\"); \nString username = dataObj.getString(\"username\"); \nString caption = dataObj.getString(\"caption\"); \nString timestamp = dataObj.getString(\"timestamp\"); // below line is to add a constant author image URL to our recycler view. \nString author_url = \"https://instagram.fnag5-1.fna.fbcdn.net/v/t51.2885-19/s320x320/75595203_828043414317991_4596848371003555840_n.jpg?_nc_ht=instagram.fnag5-1.fna.fbcdn.net&_nc_ohc=WzA_n4sdoQIAX9B5HWJ&tp=1&oh=05546141f5e40a8f02525b497745a3f2&oe=6031653B\"; \nint likesCount = 100 + (i * 10); // below line is use to add data to our modal class. \nInstaModal instaModal = new InstaModal(id, media_type, permalink, media_url, username, caption, timestamp, author_url, likesCount); // below line is use to add modal \n// class to our array list. \ninstaModalArrayList.add(instaModal); // below line we are creating an adapter class and adding our array list in it. \nInstagramFeedRVAdapter adapter = new InstagramFeedRVAdapter(instaModalArrayList, MainActivity.this); \nRecyclerView instRV = findViewById(R.id.idRVInstaFeeds); // below line is for setting linear layout manager to our recycler view. \nLinearLayoutManager linearLayoutManager = new LinearLayoutManager(MainActivity.this, RecyclerView.VERTICAL, false); // below line is to set layout manager to our recycler view. \ninstRV.setLayoutManager(linearLayoutManager); // below line is to set adapter \n// to our recycler view. \ninstRV.setAdapter(adapter); \n} \n} catch (JSONException e) { \n// handling error case. \ne.printStackTrace(); \nToast.makeText(MainActivity.this, \"Fail to get Data..\" + e.getMessage(), Toast.LENGTH_SHORT).show(); \n} \n} \n}, new Response.ErrorListener() { \n@Override\npublic void onErrorResponse(VolleyError error) { \n// handling error message. \nToast.makeText(MainActivity.this, \"Fail to get Data..\" + error, Toast.LENGTH_SHORT).show(); \n} \n}); \nqueue.add(jsonObjectRequest); \n} \n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210120175412/Screenrecorder-2021-01-20-16-33-04-649.mp4\nCheck out the project on the below link: https://github.com/ChaitanyaMunje/LibraryApp/tree/InstagramCustomListVIew"
},
{
"instruction": "m Like Custom RecyclerView in Android?We have seen implementing RecyclerView in Android with simple data inside our app. In this article, we will take a look at the implementation of Instagram like Custom RecyclerView in Android.\nWhat we are going to build in this article?\nWe will be building a simple application in which we will be displaying data from the Instagram profile, and we will be using an official Instagram API to load the data from user\u2019s Instagram profile and display that data in a custom RecyclerView. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add the below dependency in your build.gradle file \nBelow is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. // dependency for loading data from json file.\nimplementation \u2018com.android.volley:volley:1.1.1\u2019\n// dependency for loading image from url.\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019\n// dependency for creating a circle image. \nimplementation \u2018de.hdodenhof:circleimageview:3.1.0\u2019Step 3: Creating API for getting the data for generating API\nNow for creating a basic display API for Instagram posts we will be creating an API for displaying this data. You may refer to the How to Generate API URL for Public Instagram Feeds in Android? Now we have created the URL with the access token and we will use this URL to get the JSON data. \nStep 4: Adding permissions for the internet in the AndroidManifest.xml file\nAs we are loading data from the internet. For that, we will have to add the internet permissions to our AndroidManifest.xml file. Navigate to the app > AndroidManifest.xml file and add the below code to it.XML \n \n { private ArrayList instaModalArrayList; \nprivate Context context; public InstagramFeedRVAdapter(ArrayList instaModalArrayList, Context context) { \nthis.instaModalArrayList = instaModalArrayList; \nthis.context = context; \n} @NonNull\n@Override\npublic InstagramFeedRVAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { \n// inflating our layout for item of recycler view item. \nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.insta_feed_rv_item, parent, false); \nreturn new InstagramFeedRVAdapter.ViewHolder(view); \n} @Override\npublic void onBindViewHolder(@NonNull InstagramFeedRVAdapter.ViewHolder holder, int position) { \nInstaModal modal = instaModalArrayList.get(position); \nholder.authorTV.setText(modal.getUsername()); \nif (modal.getMedia_type().equals(\"IMAGE\")) { \nPicasso.get().load(modal.getMedia_url()).into(holder.postIV); \n} \nholder.desctv.setText(modal.getCaption()); \nholder.likeTV.setText(\"\" + modal.getLikesCount() + \" likes\"); \nPicasso.get().load(modal.getAuthor_url()).into(holder.authorIV); \n} @Override\npublic int getItemCount() { \nreturn instaModalArrayList.size(); \n} public class ViewHolder extends RecyclerView.ViewHolder { CircleImageView authorIV; \nprivate TextView authorTV; \nprivate ImageView postIV; \nprivate TextView likeTV, desctv; public ViewHolder(@NonNull View itemView) { \nsuper(itemView); \nauthorIV = itemView.findViewById(R.id.idCVAuthor); \nauthorTV = itemView.findViewById(R.id.idTVAuthorName); \npostIV = itemView.findViewById(R.id.idIVPost); \nlikeTV = itemView.findViewById(R.id.idTVLikes); \ndesctv = itemView.findViewById(R.id.idTVPostDesc); \n} \n} \n}Step 9: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle; \nimport android.view.View; \nimport android.widget.ProgressBar; \nimport android.widget.Toast; import androidx.appcompat.app.AppCompatActivity; \nimport androidx.recyclerview.widget.LinearLayoutManager; \nimport androidx.recyclerview.widget.RecyclerView; import com.android.volley.Request; \nimport com.android.volley.RequestQueue; \nimport com.android.volley.Response; \nimport com.android.volley.VolleyError; \nimport com.android.volley.toolbox.JsonObjectRequest; \nimport com.android.volley.toolbox.Volley; import org.json.JSONArray; \nimport org.json.JSONException; \nimport org.json.JSONObject; import java.util.ArrayList; public class MainActivity extends AppCompatActivity { // creating variables for our requestqueue, \n// array list, progressbar, edittext, \n// image button and our recycler view. \nprivate RequestQueue mRequestQueue; \nprivate ArrayList instaModalArrayList; \nprivate ProgressBar progressBar; @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // initializing our views. \nprogressBar = findViewById(R.id.idLoadingPB); \ninstaModalArrayList = new ArrayList<>(); // calling method to load \n// data in recycler view. \ngetInstagramData(); \n} private void getInstagramData() { \n// below line is use to initialize the variable for our request queue. \nmRequestQueue = Volley.newRequestQueue(MainActivity.this); // below line is use to clear cache this will \n// be use when our data is being updated. \nmRequestQueue.getCache().clear(); // below is the url for getting data \n// from API in json format. \nString url = \"Enter your URL\"; // below line we are creating a new request queue. \nRequestQueue queue = Volley.newRequestQueue(MainActivity.this); \nJsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener() { \n@Override\npublic void onResponse(JSONObject response) { \nprogressBar.setVisibility(View.GONE); \ntry { \nJSONArray dataArray = response.getJSONArray(\"data\"); \nfor (int i = 0; i < dataArray.length(); i++) { \n// below line is to extract data from JSON file. \nJSONObject dataObj = dataArray.getJSONObject(i); \nString id = dataObj.getString(\"id\"); \nString media_type = dataObj.getString(\"media_type\"); \nString permalink = dataObj.getString(\"permalink\"); \nString media_url = dataObj.getString(\"media_url\"); \nString username = dataObj.getString(\"username\"); \nString caption = dataObj.getString(\"caption\"); \nString timestamp = dataObj.getString(\"timestamp\"); // below line is to add a constant author image URL to our recycler view. \nString author_url = \"https://instagram.fnag5-1.fna.fbcdn.net/v/t51.2885-19/s320x320/75595203_828043414317991_4596848371003555840_n.jpg?_nc_ht=instagram.fnag5-1.fna.fbcdn.net&_nc_ohc=WzA_n4sdoQIAX9B5HWJ&tp=1&oh=05546141f5e40a8f02525b497745a3f2&oe=6031653B\"; \nint likesCount = 100 + (i * 10); // below line is use to add data to our modal class. \nInstaModal instaModal = new InstaModal(id, media_type, permalink, media_url, username, caption, timestamp, author_url, likesCount); // below line is use to add modal \n// class to our array list. \ninstaModalArrayList.add(instaModal); // below line we are creating an adapter class and adding our array list in it. \nInstagramFeedRVAdapter adapter = new InstagramFeedRVAdapter(instaModalArrayList, MainActivity.this); \nRecyclerView instRV = findViewById(R.id.idRVInstaFeeds); // below line is for setting linear layout manager to our recycler view. \nLinearLayoutManager linearLayoutManager = new LinearLayoutManager(MainActivity.this, RecyclerView.VERTICAL, false); // below line is to set layout manager to our recycler view. \ninstRV.setLayoutManager(linearLayoutManager); // below line is to set adapter \n// to our recycler view. \ninstRV.setAdapter(adapter); \n} \n} catch (JSONException e) { \n// handling error case. \ne.printStackTrace(); \nToast.makeText(MainActivity.this, \"Fail to get Data..\" + e.getMessage(), Toast.LENGTH_SHORT).show(); \n} \n} \n}, new Response.ErrorListener() { \n@Override\npublic void onErrorResponse(VolleyError error) { \n// handling error message. \nToast.makeText(MainActivity.this, \"Fail to get Data..\" + error, Toast.LENGTH_SHORT).show(); \n} \n}); \nqueue.add(jsonObjectRequest); \n} \n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210120175412/Screenrecorder-2021-01-20-16-33-04-649.mp4\nCheck out the project on the below link: https://github.com/ChaitanyaMunje/LibraryApp/tree/InstagramCustomListVIew",
"input": "",
"output": "Like Custom RecyclerView in Android?We have seen implementing RecyclerView in Android with simple data inside our app. In this article, we will take a look at the implementation of Facebook like Custom RecyclerView in Android. \nWhat we are going to build in this article?\nWe will be building a simple application in which we will display the Facebook like RecyclerView in our Android app. We will be fetching this data from a simple API (https://jsonkeeper.com/b/OB3B) which is given in the article. With the help of this API, we will be displaying that data in our RecyclerView. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add the below dependency in your build.gradle file Below is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. // dependency for loading data from json file.\nimplementation \u2018com.android.volley:volley:1.1.1\u2019\n// dependency for loading image from url.\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019\n// dependency for creating a circle image. \nimplementation \u2018de.hdodenhof:circleimageview:3.1.0\u2019Step 3: Adding internet permissions in your AndroidManifest.xml file\nAs we are loading data from the internet, for that, we will have to add the internet permissions to our AndroidManifest.xml file. Navigate to the app > AndroidManifest.xml file and add the below code to it. XML \n\n\n Step 6: Creating a layout file for our item of RecyclerView\nNavigate to the app > res > layout > Right-click on it > New > layout Resource file and name it as facebook_feed_rv_item and add the below code to it. Comments are added in the code to get to know in more detail.Note: Icons used in this file are present in the drawable folder. Navigate to the app > res > drawable folder and add your icons to that folder.XML \n\n\n {// arraylist for our facebook feeds.\nprivate ArrayList facebookFeedModalArrayList;\nprivate Context context;// creating a constructor for our adapter class.\npublic FacebookFeedRVAdapter(ArrayList facebookFeedModalArrayList, Context context) {\nthis.facebookFeedModalArrayList = facebookFeedModalArrayList;\nthis.context = context;\n}@NonNull\n@Override\npublic FacebookFeedRVAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {\n// inflating our layout for item of recycler view item.\nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.facebook_feed_rv_item, parent, false);\nreturn new FacebookFeedRVAdapter.ViewHolder(view);\n}@Override\npublic void onBindViewHolder(@NonNull FacebookFeedRVAdapter.ViewHolder holder, int position) {\n// getting data from array list and setting it to our modal class.\nFacebookFeedModal modal = facebookFeedModalArrayList.get(position);// setting data to each view of recyclerview item.\nPicasso.get().load(modal.getAuthorImage()).into(holder.authorIV);\nholder.authorNameTV.setText(modal.getAuthorName());\nholder.timeTV.setText(modal.getPostDate());\nholder.descTV.setText(modal.getPostDescription());\nPicasso.get().load(modal.getPostIV()).into(holder.postIV);\nholder.likesTV.setText(modal.getPostLikes());\nholder.commentsTV.setText(modal.getPostComments());\n}@Override\npublic int getItemCount() {\n// returning the size of our array list.\nreturn facebookFeedModalArrayList.size();\n}public class ViewHolder extends RecyclerView.ViewHolder {\n// creating variables for our views \n// of recycler view items.\nprivate CircleImageView authorIV;\nprivate TextView authorNameTV, timeTV, descTV;\nprivate ImageView postIV;\nprivate TextView likesTV, commentsTV;\nprivate LinearLayout shareLL;public ViewHolder(@NonNull View itemView) {\nsuper(itemView);\n// initializing our variables\nshareLL = itemView.findViewById(R.id.idLLShare);\nauthorIV = itemView.findViewById(R.id.idCVAuthor);\nauthorNameTV = itemView.findViewById(R.id.idTVAuthorName);\ntimeTV = itemView.findViewById(R.id.idTVTime);\ndescTV = itemView.findViewById(R.id.idTVDescription);\npostIV = itemView.findViewById(R.id.idIVPost);\nlikesTV = itemView.findViewById(R.id.idTVLikes);\ncommentsTV = itemView.findViewById(R.id.idTVComments);\n}\n}\n}Step 9: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle;\nimport android.view.View;\nimport android.widget.ProgressBar;\nimport android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;\nimport androidx.recyclerview.widget.LinearLayoutManager;\nimport androidx.recyclerview.widget.RecyclerView;import com.android.volley.Request;\nimport com.android.volley.RequestQueue;\nimport com.android.volley.Response;\nimport com.android.volley.VolleyError;\nimport com.android.volley.toolbox.JsonObjectRequest;\nimport com.android.volley.toolbox.Volley;import org.json.JSONArray;\nimport org.json.JSONException;\nimport org.json.JSONObject;import java.util.ArrayList;public class MainActivity extends AppCompatActivity {// creating variables for our requestqueue,\n// array list, progressbar, edittext,\n// image button and our recycler view.\nprivate RequestQueue mRequestQueue;\nprivate ArrayList instaModalArrayList;\nprivate ArrayList facebookFeedModalArrayList;\nprivate ProgressBar progressBar;@Override\nprotected void onCreate(Bundle savedInstanceState) {\nsuper.onCreate(savedInstanceState);\nsetContentView(R.layout.activity_main);// initializing our views.\nprogressBar = findViewById(R.id.idLoadingPB);// calling method to load\n// data in recycler view.\ngetFacebookFeeds();\n}private void getFacebookFeeds() {\nfacebookFeedModalArrayList = new ArrayList<>();// below line is use to initialize the variable for our request queue.\nmRequestQueue = Volley.newRequestQueue(MainActivity.this);// below line is use to clear\n// cache this will be use when\n// our data is being updated.\nmRequestQueue.getCache().clear();// below is the url stored in\n// string for our sample data\nString url = \"https://jsonkeeper.com/b/OB3B\";JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener() {\n@Override\npublic void onResponse(JSONObject response) {\nprogressBar.setVisibility(View.GONE);\ntry {\n// in below line we are extracting the data from json object.\nString authorName = response.getString(\"authorName\");\nString authorImage = response.getString(\"authorImage\");// below line is to get json array from our json object.\nJSONArray feedsArray = response.getJSONArray(\"feeds\");// running a for loop to add data to our array list\nfor (int i = 0; i < feedsArray.length(); i++) {\n// getting json object of our json array.\nJSONObject feedsObj = feedsArray.getJSONObject(i);// extracting data from our json object.\nString postDate = feedsObj.getString(\"postDate\");\nString postDescription = feedsObj.getString(\"postDescription\");\nString postIV = feedsObj.getString(\"postIV\");\nString postLikes = feedsObj.getString(\"postLikes\");\nString postComments = feedsObj.getString(\"postComments\");// adding data to our modal class.\nFacebookFeedModal feedModal = new FacebookFeedModal(authorImage, authorName, postDate, postDescription, postIV, postLikes, postComments);\nfacebookFeedModalArrayList.add(feedModal);// below line we are creating an adapter class and adding our array list in it.\nFacebookFeedRVAdapter adapter = new FacebookFeedRVAdapter(facebookFeedModalArrayList, MainActivity.this);\nRecyclerView instRV = findViewById(R.id.idRVInstaFeeds);// below line is for setting linear layout manager to our recycler view.\nLinearLayoutManager linearLayoutManager = new LinearLayoutManager(MainActivity.this, RecyclerView.VERTICAL, false);// below line is to set layout \n// manager to our recycler view.\ninstRV.setLayoutManager(linearLayoutManager);// below line is to set adapter \n// to our recycler view.\ninstRV.setAdapter(adapter);\n}\n} catch (JSONException e) {\ne.printStackTrace();\n}\n}\n}, new Response.ErrorListener() {\n@Override\npublic void onErrorResponse(VolleyError error) {\nToast.makeText(MainActivity.this, \"Fail to get data with error \" + error, Toast.LENGTH_SHORT).show();\n}\n});\nmRequestQueue.add(jsonObjectRequest);\n}\n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210127131954/Build-a-Facebook-Like-Custom-RecyclerView-in-Android.mp4\nYou can check the project on the below link: https://github.com/ChaitanyaMunje/LibraryApp/tree/FacebookBranch"
},
{
"instruction": "Like Custom RecyclerView in Android?We have seen implementing RecyclerView in Android with simple data inside our app. In this article, we will take a look at the implementation of Facebook like Custom RecyclerView in Android. \nWhat we are going to build in this article?\nWe will be building a simple application in which we will display the Facebook like RecyclerView in our Android app. We will be fetching this data from a simple API (https://jsonkeeper.com/b/OB3B) which is given in the article. With the help of this API, we will be displaying that data in our RecyclerView. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going toimplement this project using theJavalanguage.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Add the below dependency in your build.gradle file Below is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. // dependency for loading data from json file.\nimplementation \u2018com.android.volley:volley:1.1.1\u2019\n// dependency for loading image from url.\nimplementation \u2018com.squareup.picasso:picasso:2.71828\u2019\n// dependency for creating a circle image. \nimplementation \u2018de.hdodenhof:circleimageview:3.1.0\u2019Step 3: Adding internet permissions in your AndroidManifest.xml file\nAs we are loading data from the internet, for that, we will have to add the internet permissions to our AndroidManifest.xml file. Navigate to the app > AndroidManifest.xml file and add the below code to it. XML \n\n\n Step 6: Creating a layout file for our item of RecyclerView\nNavigate to the app > res > layout > Right-click on it > New > layout Resource file and name it as facebook_feed_rv_item and add the below code to it. Comments are added in the code to get to know in more detail.Note: Icons used in this file are present in the drawable folder. Navigate to the app > res > drawable folder and add your icons to that folder.XML \n\n\n {// arraylist for our facebook feeds.\nprivate ArrayList facebookFeedModalArrayList;\nprivate Context context;// creating a constructor for our adapter class.\npublic FacebookFeedRVAdapter(ArrayList facebookFeedModalArrayList, Context context) {\nthis.facebookFeedModalArrayList = facebookFeedModalArrayList;\nthis.context = context;\n}@NonNull\n@Override\npublic FacebookFeedRVAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {\n// inflating our layout for item of recycler view item.\nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.facebook_feed_rv_item, parent, false);\nreturn new FacebookFeedRVAdapter.ViewHolder(view);\n}@Override\npublic void onBindViewHolder(@NonNull FacebookFeedRVAdapter.ViewHolder holder, int position) {\n// getting data from array list and setting it to our modal class.\nFacebookFeedModal modal = facebookFeedModalArrayList.get(position);// setting data to each view of recyclerview item.\nPicasso.get().load(modal.getAuthorImage()).into(holder.authorIV);\nholder.authorNameTV.setText(modal.getAuthorName());\nholder.timeTV.setText(modal.getPostDate());\nholder.descTV.setText(modal.getPostDescription());\nPicasso.get().load(modal.getPostIV()).into(holder.postIV);\nholder.likesTV.setText(modal.getPostLikes());\nholder.commentsTV.setText(modal.getPostComments());\n}@Override\npublic int getItemCount() {\n// returning the size of our array list.\nreturn facebookFeedModalArrayList.size();\n}public class ViewHolder extends RecyclerView.ViewHolder {\n// creating variables for our views \n// of recycler view items.\nprivate CircleImageView authorIV;\nprivate TextView authorNameTV, timeTV, descTV;\nprivate ImageView postIV;\nprivate TextView likesTV, commentsTV;\nprivate LinearLayout shareLL;public ViewHolder(@NonNull View itemView) {\nsuper(itemView);\n// initializing our variables\nshareLL = itemView.findViewById(R.id.idLLShare);\nauthorIV = itemView.findViewById(R.id.idCVAuthor);\nauthorNameTV = itemView.findViewById(R.id.idTVAuthorName);\ntimeTV = itemView.findViewById(R.id.idTVTime);\ndescTV = itemView.findViewById(R.id.idTVDescription);\npostIV = itemView.findViewById(R.id.idIVPost);\nlikesTV = itemView.findViewById(R.id.idTVLikes);\ncommentsTV = itemView.findViewById(R.id.idTVComments);\n}\n}\n}Step 9: Working with the MainActivity.java file\nGo to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.Java import android.os.Bundle;\nimport android.view.View;\nimport android.widget.ProgressBar;\nimport android.widget.Toast;import androidx.appcompat.app.AppCompatActivity;\nimport androidx.recyclerview.widget.LinearLayoutManager;\nimport androidx.recyclerview.widget.RecyclerView;import com.android.volley.Request;\nimport com.android.volley.RequestQueue;\nimport com.android.volley.Response;\nimport com.android.volley.VolleyError;\nimport com.android.volley.toolbox.JsonObjectRequest;\nimport com.android.volley.toolbox.Volley;import org.json.JSONArray;\nimport org.json.JSONException;\nimport org.json.JSONObject;import java.util.ArrayList;public class MainActivity extends AppCompatActivity {// creating variables for our requestqueue,\n// array list, progressbar, edittext,\n// image button and our recycler view.\nprivate RequestQueue mRequestQueue;\nprivate ArrayList instaModalArrayList;\nprivate ArrayList facebookFeedModalArrayList;\nprivate ProgressBar progressBar;@Override\nprotected void onCreate(Bundle savedInstanceState) {\nsuper.onCreate(savedInstanceState);\nsetContentView(R.layout.activity_main);// initializing our views.\nprogressBar = findViewById(R.id.idLoadingPB);// calling method to load\n// data in recycler view.\ngetFacebookFeeds();\n}private void getFacebookFeeds() {\nfacebookFeedModalArrayList = new ArrayList<>();// below line is use to initialize the variable for our request queue.\nmRequestQueue = Volley.newRequestQueue(MainActivity.this);// below line is use to clear\n// cache this will be use when\n// our data is being updated.\nmRequestQueue.getCache().clear();// below is the url stored in\n// string for our sample data\nString url = \"https://jsonkeeper.com/b/OB3B\";JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener() {\n@Override\npublic void onResponse(JSONObject response) {\nprogressBar.setVisibility(View.GONE);\ntry {\n// in below line we are extracting the data from json object.\nString authorName = response.getString(\"authorName\");\nString authorImage = response.getString(\"authorImage\");// below line is to get json array from our json object.\nJSONArray feedsArray = response.getJSONArray(\"feeds\");// running a for loop to add data to our array list\nfor (int i = 0; i < feedsArray.length(); i++) {\n// getting json object of our json array.\nJSONObject feedsObj = feedsArray.getJSONObject(i);// extracting data from our json object.\nString postDate = feedsObj.getString(\"postDate\");\nString postDescription = feedsObj.getString(\"postDescription\");\nString postIV = feedsObj.getString(\"postIV\");\nString postLikes = feedsObj.getString(\"postLikes\");\nString postComments = feedsObj.getString(\"postComments\");// adding data to our modal class.\nFacebookFeedModal feedModal = new FacebookFeedModal(authorImage, authorName, postDate, postDescription, postIV, postLikes, postComments);\nfacebookFeedModalArrayList.add(feedModal);// below line we are creating an adapter class and adding our array list in it.\nFacebookFeedRVAdapter adapter = new FacebookFeedRVAdapter(facebookFeedModalArrayList, MainActivity.this);\nRecyclerView instRV = findViewById(R.id.idRVInstaFeeds);// below line is for setting linear layout manager to our recycler view.\nLinearLayoutManager linearLayoutManager = new LinearLayoutManager(MainActivity.this, RecyclerView.VERTICAL, false);// below line is to set layout \n// manager to our recycler view.\ninstRV.setLayoutManager(linearLayoutManager);// below line is to set adapter \n// to our recycler view.\ninstRV.setAdapter(adapter);\n}\n} catch (JSONException e) {\ne.printStackTrace();\n}\n}\n}, new Response.ErrorListener() {\n@Override\npublic void onErrorResponse(VolleyError error) {\nToast.makeText(MainActivity.this, \"Fail to get data with error \" + error, Toast.LENGTH_SHORT).show();\n}\n});\nmRequestQueue.add(jsonObjectRequest);\n}\n}Now run your app and see the output of the app.\nOutput:https://media.geeksforgeeks.org/wp-content/uploads/20210127131954/Build-a-Facebook-Like-Custom-RecyclerView-in-Android.mp4\nYou can check the project on the below link: https://github.com/ChaitanyaMunje/LibraryApp/tree/FacebookBranch",
"input": "",
"output": "nd MVVM Architecture Pattern in AndroidDeveloping an android application by applying a software architecture pattern is always preferred by the developers. An architecture pattern gives modularity to the project files and assures that all the codes get covered in Unit testing. It makes the task easy for developers to maintain the software and to expand the features of the application in the future. MVC (Model \u2014 View \u2014 Controller) and MVVM (Model \u2014 View \u2014 ViewModel) are the two most popular android architectures among developers.\nThe Model\u2014View\u2014Controller(MVC) Pattern\nThe MVC pattern suggests splitting the code into 3 components. While creating the class/file of the application, the developer must categorize it into one of the following three layers:Model: This component stores the application data. It has no knowledge about the interface. The model is responsible for handling the domain logic(real-world business rules) and communication with the database and network layers.\nView: It is the UI(User Interface) layer that holds components that are visible on the screen. Moreover, it provides the visualization of the data stored in the Model and offers interaction to the user.\nController: This component establishes the relationship between the View and the Model. It contains the core application logic and gets informed of the user\u2019s response and updates the Model as per the need.The Model \u2014 View \u2014 ViewModel (MVVM) Pattern\nMVVM pattern has some similarities with the MVP(Model \u2014 View \u2014 Presenter) design pattern as the Presenter role is played by the ViewModel. However, the drawbacks of the MVP pattern has been solved by MVVM. It suggests separating the data presentation logic(Views or UI) from the core business logic part of the application. The separate code layers of MVVM are:Model: This layer is responsible for the abstraction of the data sources. Model and ViewModel work together to get and save the data.\nView: The purpose of this layer is to inform the ViewModel about the user\u2019s action. This layer observes the ViewModel and does not contain any kind of application logic.\nViewModel: It exposes those data streams which are relevant to the View. Moreover, it servers as a link between the Model and the View.Difference Between MVC and MVVM Design PatternMVC(Model View Controller)MVVM(Model View ViewModel)Oldest android app architecture.\nIndustry-recognized architecture pattern for applications.User Inputs are handled by the Controller.\nThe View takes the input from the user and acts as the entry point of the application.Controller and View exist with the one-to-many relationship. One Controller can select different View based upon required operation.\nMultiple View can be mapped with single ViewModel and thus, the one-to-many relationship exists between View and ViewModel.The View has no knowledge about the Controller.\nThe View has reference to the ViewModel.This architecture has high dependency on the Android APIs.\nHas low or no dependency on the Android APIs.Difficult to make changes and modify the app features as the code layers are tightly coupled.\nEasy to make changes in application. However, if data binding logic is too complex, it will be a little harder to debug the application.Limited support to Unit testing.\nUnit testability is highest in this architecture.It does not follow modular and single responsibility principle.\nFollows modular and single responsibility principle.Overall, the main difference between MVC and MVVM is the role of the mediator component. In MVC, the Controller serves as the mediator between the View and the Model, while in MVVM, the ViewModel serves as the mediator between the View and the Model. MVC is a simpler pattern, while MVVM is more flexible and allows for a cleaner separation of concerns between the different layers of the application. While both MVC and MVVM are useful patterns for organizing the code for a software application, MVVM offers a number of advantages over MVC, here are a few of them:Improved separation of concerns: In MVVM, the ViewModel serves as a mediator between the View and the Model, which allows for a cleaner separation of concerns between the different layers of the application. This can make it easier to maintain and modify the codebase over time.\nBetter testability: Because the ViewModel is responsible for exposing the data and logic of the Model to the View, it can be easier to test the ViewModel separately from the View. This can make it easier to ensure that the application is functioning correctly and can make it easier to identify and fix bugs.\nGreater flexibility: The ViewModel in MVVM is more flexible than the Model in MVC, as it can expose data and logic from the Model in a way that is easier for the View to consume. This can make it easier to create different views for the same data and logic, or to reuse the same ViewModel with multiple views.\nBetter support for multiple developers: Because the MVVM pattern allows for a cleaner separation of concerns between the different layers of the application, it can be easier for multiple developers to work on different parts of the codebase concurrently. This can improve the efficiency of the development process and reduce the risk of conflicts between different parts of the codebase."
},
{
"instruction": "nd MVVM Architecture Pattern in AndroidDeveloping an android application by applying a software architecture pattern is always preferred by the developers. An architecture pattern gives modularity to the project files and assures that all the codes get covered in Unit testing. It makes the task easy for developers to maintain the software and to expand the features of the application in the future. MVC (Model \u2014 View \u2014 Controller) and MVVM (Model \u2014 View \u2014 ViewModel) are the two most popular android architectures among developers.\nThe Model\u2014View\u2014Controller(MVC) Pattern\nThe MVC pattern suggests splitting the code into 3 components. While creating the class/file of the application, the developer must categorize it into one of the following three layers:Model: This component stores the application data. It has no knowledge about the interface. The model is responsible for handling the domain logic(real-world business rules) and communication with the database and network layers.\nView: It is the UI(User Interface) layer that holds components that are visible on the screen. Moreover, it provides the visualization of the data stored in the Model and offers interaction to the user.\nController: This component establishes the relationship between the View and the Model. It contains the core application logic and gets informed of the user\u2019s response and updates the Model as per the need.The Model \u2014 View \u2014 ViewModel (MVVM) Pattern\nMVVM pattern has some similarities with the MVP(Model \u2014 View \u2014 Presenter) design pattern as the Presenter role is played by the ViewModel. However, the drawbacks of the MVP pattern has been solved by MVVM. It suggests separating the data presentation logic(Views or UI) from the core business logic part of the application. The separate code layers of MVVM are:Model: This layer is responsible for the abstraction of the data sources. Model and ViewModel work together to get and save the data.\nView: The purpose of this layer is to inform the ViewModel about the user\u2019s action. This layer observes the ViewModel and does not contain any kind of application logic.\nViewModel: It exposes those data streams which are relevant to the View. Moreover, it servers as a link between the Model and the View.Difference Between MVC and MVVM Design PatternMVC(Model View Controller)MVVM(Model View ViewModel)Oldest android app architecture.\nIndustry-recognized architecture pattern for applications.User Inputs are handled by the Controller.\nThe View takes the input from the user and acts as the entry point of the application.Controller and View exist with the one-to-many relationship. One Controller can select different View based upon required operation.\nMultiple View can be mapped with single ViewModel and thus, the one-to-many relationship exists between View and ViewModel.The View has no knowledge about the Controller.\nThe View has reference to the ViewModel.This architecture has high dependency on the Android APIs.\nHas low or no dependency on the Android APIs.Difficult to make changes and modify the app features as the code layers are tightly coupled.\nEasy to make changes in application. However, if data binding logic is too complex, it will be a little harder to debug the application.Limited support to Unit testing.\nUnit testability is highest in this architecture.It does not follow modular and single responsibility principle.\nFollows modular and single responsibility principle.Overall, the main difference between MVC and MVVM is the role of the mediator component. In MVC, the Controller serves as the mediator between the View and the Model, while in MVVM, the ViewModel serves as the mediator between the View and the Model. MVC is a simpler pattern, while MVVM is more flexible and allows for a cleaner separation of concerns between the different layers of the application. While both MVC and MVVM are useful patterns for organizing the code for a software application, MVVM offers a number of advantages over MVC, here are a few of them:Improved separation of concerns: In MVVM, the ViewModel serves as a mediator between the View and the Model, which allows for a cleaner separation of concerns between the different layers of the application. This can make it easier to maintain and modify the codebase over time.\nBetter testability: Because the ViewModel is responsible for exposing the data and logic of the Model to the View, it can be easier to test the ViewModel separately from the View. This can make it easier to ensure that the application is functioning correctly and can make it easier to identify and fix bugs.\nGreater flexibility: The ViewModel in MVVM is more flexible than the Model in MVC, as it can expose data and logic from the Model in a way that is easier for the View to consume. This can make it easier to create different views for the same data and logic, or to reuse the same ViewModel with multiple views.\nBetter support for multiple developers: Because the MVVM pattern allows for a cleaner separation of concerns between the different layers of the application, it can be easier for multiple developers to work on different parts of the codebase concurrently. This can improve the efficiency of the development process and reduce the risk of conflicts between different parts of the codebase.",
"input": "",
"output": "d Grid in Android With ExampleGridView: A ViewGroup that shows the items in a two-dimensional scrolling grid. In Grid View, each grid is of the same size .i.e., the height and width of each grid are equal. It shows symmetric items in the views.Staggered GridView: This ViewGroup is the extension of Grid View. In this view, the Grid is of varying size .i.e., their height and width may vary. It shows asymmetric items in the views. It automatically sets the item views according to its height and width.In order to use RecyclerView for creating staggering grid views, we need to use StaggeredGridLayoutManager. LayoutManager is responsible for measuring and positioning item views in the RecyclerView and also recycle the item views when they are no longer visible to the user. There are three types of built-in layout managers.LinearLayoutManager: It is used to show item views in a vertical and horizontal list.\nGridLayoutManager: It is used to show item views grid views.\nStaggeredLayoutManager: It is used to show item views in staggered views.We can also create a custom layout manager by RecyclerView.LayoutManager class.\nStaggeredGridLayoutManager(int spanCount, int orientation)Creates staggered grid layout with given parameters\nThe first parameter, spanCount is used to set the number of columns in a vertical orientation or the number of rows in the horizontal orientation\nThe second parameter, orientation is used to set the vertical or horizontal orientationStaggered Grid with Vertical OrientationRecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerView);\n// staggeredGridLayoutManager with 3 columns and vertical orientation\nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayoutManager.VERTICAL);\n// setting recycler view layout to staggered grid\nrecyclerView.setLayoutManager(staggeredGridLayoutManager);Staggered Grid with Horizontal OrientationRecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerView);\n// staggeredGridLayoutManager with 3 rows and horizontal orientation\nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayoutManager.HORIZONTAL);\n// setting recycler view layout to staggered grid\nrecyclerView.setLayoutManager(staggeredGridLayoutManager);Example\nIn this example, we would store data into ArrayList which is used for populating RecyclerView. After that we set the layout manager of RecyclerView as a staggered grid view and then, we set the Adapter for RecyclerView to show item views. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Adding dependencies\nWe are going to use the RecyclerView. So, we need to add the dependency of it. For adding the dependency Go to Gradle Scripts > build.gradle(Module: app) and add the following dependencies. After adding these dependencies you need to click on Sync Now.dependencies {\n implementation \u2018androidx.recyclerview:recyclerview:1.1.0\u2019\n}Before moving further let\u2019s add some color attributes in order to enhance the app bar. Go to app > res > values > colors.xml and add the following color attributes.XML \n#0F9D58 \n#16E37F \n#03DAC5 \n Step 3: Working with the activity_main.xml file\nIn this step, we will create a RecyclerView layout in the activity_main.xml file. Go to app > res > layout > activity_main.xml and add the following code snippet.XML \n \n { \nArrayList images; \nContext context; // Constructor for initialization \npublic Adapter(Context context, ArrayList images) { \nthis.context = context; \nthis.images = images; \n} @NonNull\n@Override\npublic Adapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { \n// Inflating the Layout(Instantiates list_item.xml layout file into View object) \nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false); // Passing view to ViewHolder \nAdapter.ViewHolder viewHolder = new Adapter.ViewHolder(view); \nreturn viewHolder; \n} // Binding data to the into specified position \n@Override\npublic void onBindViewHolder(@NonNull Adapter.ViewHolder holder, int position) { \n// TypeCast Object to int type \nint res = (int) images.get(position); \nholder.images.setImageResource(res); \n} @Override\npublic int getItemCount() { \n// Returns number of items currently available in Adapter \nreturn images.size(); \n} // Initializing the Views \npublic class ViewHolder extends RecyclerView.ViewHolder { \nImageView images; public ViewHolder(View view) { \nsuper(view); \nimages = (ImageView) view.findViewById(R.id.imageView); \n} \n} \n}Step 6: Working with the MainActivity.java file\nIn MainActivity.java class we create an ArrayList for storing images. These images are placed in the drawable folder(app > res > drawable). You can use any images in place of these. And then we get the reference RecyclerView and set the LayoutManager as StaggeredGridLayoutManager and Adapter, to show items in RecyclerView. Below is the code for the MainActivity.java file.Java import android.os.Bundle; \nimport androidx.appcompat.app.AppCompatActivity; \nimport androidx.recyclerview.widget.LinearLayoutManager; \nimport androidx.recyclerview.widget.RecyclerView; \nimport androidx.recyclerview.widget.StaggeredGridLayoutManager; \nimport java.util.ArrayList; \nimport java.util.Arrays; public class MainActivity extends AppCompatActivity { RecyclerView recyclerView; // Using ArrayList to store images data \nArrayList images = new ArrayList<>(Arrays.asList(R.drawable.img_1, R.drawable.img_2, R.drawable.img_3, \nR.drawable.img_4, R.drawable.img_5, R.drawable.img_6, R.drawable.img_7, R.drawable.img_8, \nR.drawable.img_9, R.drawable.img_10)); @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // Getting reference of recyclerView \nrecyclerView = (RecyclerView) findViewById(R.id.recyclerView); // Setting the layout as Staggered Grid for vertical orientation \nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(2, LinearLayoutManager.VERTICAL); \nrecyclerView.setLayoutManager(staggeredGridLayoutManager); // Sending reference and data to Adapter \nAdapter adapter = new Adapter(MainActivity.this, images); // Setting Adapter to RecyclerView \nrecyclerView.setAdapter(adapter); \n} \n}Output: Run on Emulatorhttps://media.geeksforgeeks.org/wp-content/uploads/20201113000122/RecyclerView-as-Staggered-Grid-in-Android.mp4"
},
{
"instruction": "d Grid in Android With ExampleGridView: A ViewGroup that shows the items in a two-dimensional scrolling grid. In Grid View, each grid is of the same size .i.e., the height and width of each grid are equal. It shows symmetric items in the views.Staggered GridView: This ViewGroup is the extension of Grid View. In this view, the Grid is of varying size .i.e., their height and width may vary. It shows asymmetric items in the views. It automatically sets the item views according to its height and width.In order to use RecyclerView for creating staggering grid views, we need to use StaggeredGridLayoutManager. LayoutManager is responsible for measuring and positioning item views in the RecyclerView and also recycle the item views when they are no longer visible to the user. There are three types of built-in layout managers.LinearLayoutManager: It is used to show item views in a vertical and horizontal list.\nGridLayoutManager: It is used to show item views grid views.\nStaggeredLayoutManager: It is used to show item views in staggered views.We can also create a custom layout manager by RecyclerView.LayoutManager class.\nStaggeredGridLayoutManager(int spanCount, int orientation)Creates staggered grid layout with given parameters\nThe first parameter, spanCount is used to set the number of columns in a vertical orientation or the number of rows in the horizontal orientation\nThe second parameter, orientation is used to set the vertical or horizontal orientationStaggered Grid with Vertical OrientationRecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerView);\n// staggeredGridLayoutManager with 3 columns and vertical orientation\nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayoutManager.VERTICAL);\n// setting recycler view layout to staggered grid\nrecyclerView.setLayoutManager(staggeredGridLayoutManager);Staggered Grid with Horizontal OrientationRecyclerView recyclerView = (RecyclerView)findViewById(R.id.recyclerView);\n// staggeredGridLayoutManager with 3 rows and horizontal orientation\nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayoutManager.HORIZONTAL);\n// setting recycler view layout to staggered grid\nrecyclerView.setLayoutManager(staggeredGridLayoutManager);Example\nIn this example, we would store data into ArrayList which is used for populating RecyclerView. After that we set the layout manager of RecyclerView as a staggered grid view and then, we set the Adapter for RecyclerView to show item views. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language.Step by Step Implementation\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.\nStep 2: Adding dependencies\nWe are going to use the RecyclerView. So, we need to add the dependency of it. For adding the dependency Go to Gradle Scripts > build.gradle(Module: app) and add the following dependencies. After adding these dependencies you need to click on Sync Now.dependencies {\n implementation \u2018androidx.recyclerview:recyclerview:1.1.0\u2019\n}Before moving further let\u2019s add some color attributes in order to enhance the app bar. Go to app > res > values > colors.xml and add the following color attributes.XML \n#0F9D58 \n#16E37F \n#03DAC5 \n Step 3: Working with the activity_main.xml file\nIn this step, we will create a RecyclerView layout in the activity_main.xml file. Go to app > res > layout > activity_main.xml and add the following code snippet.XML \n \n { \nArrayList images; \nContext context; // Constructor for initialization \npublic Adapter(Context context, ArrayList images) { \nthis.context = context; \nthis.images = images; \n} @NonNull\n@Override\npublic Adapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) { \n// Inflating the Layout(Instantiates list_item.xml layout file into View object) \nView view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false); // Passing view to ViewHolder \nAdapter.ViewHolder viewHolder = new Adapter.ViewHolder(view); \nreturn viewHolder; \n} // Binding data to the into specified position \n@Override\npublic void onBindViewHolder(@NonNull Adapter.ViewHolder holder, int position) { \n// TypeCast Object to int type \nint res = (int) images.get(position); \nholder.images.setImageResource(res); \n} @Override\npublic int getItemCount() { \n// Returns number of items currently available in Adapter \nreturn images.size(); \n} // Initializing the Views \npublic class ViewHolder extends RecyclerView.ViewHolder { \nImageView images; public ViewHolder(View view) { \nsuper(view); \nimages = (ImageView) view.findViewById(R.id.imageView); \n} \n} \n}Step 6: Working with the MainActivity.java file\nIn MainActivity.java class we create an ArrayList for storing images. These images are placed in the drawable folder(app > res > drawable). You can use any images in place of these. And then we get the reference RecyclerView and set the LayoutManager as StaggeredGridLayoutManager and Adapter, to show items in RecyclerView. Below is the code for the MainActivity.java file.Java import android.os.Bundle; \nimport androidx.appcompat.app.AppCompatActivity; \nimport androidx.recyclerview.widget.LinearLayoutManager; \nimport androidx.recyclerview.widget.RecyclerView; \nimport androidx.recyclerview.widget.StaggeredGridLayoutManager; \nimport java.util.ArrayList; \nimport java.util.Arrays; public class MainActivity extends AppCompatActivity { RecyclerView recyclerView; // Using ArrayList to store images data \nArrayList images = new ArrayList<>(Arrays.asList(R.drawable.img_1, R.drawable.img_2, R.drawable.img_3, \nR.drawable.img_4, R.drawable.img_5, R.drawable.img_6, R.drawable.img_7, R.drawable.img_8, \nR.drawable.img_9, R.drawable.img_10)); @Override\nprotected void onCreate(Bundle savedInstanceState) { \nsuper.onCreate(savedInstanceState); \nsetContentView(R.layout.activity_main); // Getting reference of recyclerView \nrecyclerView = (RecyclerView) findViewById(R.id.recyclerView); // Setting the layout as Staggered Grid for vertical orientation \nStaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(2, LinearLayoutManager.VERTICAL); \nrecyclerView.setLayoutManager(staggeredGridLayoutManager); // Sending reference and data to Adapter \nAdapter adapter = new Adapter(MainActivity.this, images); // Setting Adapter to RecyclerView \nrecyclerView.setAdapter(adapter); \n} \n}Output: Run on Emulatorhttps://media.geeksforgeeks.org/wp-content/uploads/20201113000122/RecyclerView-as-Staggered-Grid-in-Android.mp4",
"input": "",
"output": "JSON (JavaScript Object Notation) is a straightforward data exchange format to interchange the server\u2019s data, and it is a better alternative for XML. This is because JSON is a lightweight and structured language. Android supports all the JSON classes such as JSONStringer, JSONObject, JSONArray, and all other forms to parse the JSON data and fetch the required information by the program. JSON\u2019s main advantage is that it is a language-independent, and the JSON object will contain data like a key/value pair. In general, JSON nodes will start with a square bracket ([) or with a curly bracket ({). The square and curly bracket\u2019s primary difference is that the square bracket ([) represents the beginning of a JSONArray node. Whereas, the curly bracket ({) represents a JSONObject. So one needs to call the appropriate method to get the data. Sometimes JSON data start with [. We then need to use the getJSONArray() method to get the data. Similarly, if it starts with {, then we need to use the getJSONobject() method. The syntax of the JSON file is as following:\n{ \n\"Name\": \"GeeksforGeeks\", \n\"Estd\": 2009, \n\"age\": 10, \n\"address\": { \n \"buildingAddress\": \"5th & 6th Floor Royal Kapsons, A- 118\", \n \"city\": \"Sector- 136, Noida\", \n \"state\": \"Uttar Pradesh (201305)\", \n \"postalCode\": \"201305\"\n}, In this article, we are going to parse a JSON file in Android. Note that we are going toimplement this project using theKotlinlanguage.\nStep by Step Implementation\nTo parse a JSON file in Android, follow the following steps:\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Working with the activity_main.xml file\nGo to the activity_main.xml file which represents the UI of the application. Create a ListView as shown. Below is the code for theactivity_main.xml file.XML \n \n \n>() // Declaring the listView from the layout file \nval lv = findViewById(R.id.user_list) // Initializing the JSON object and extracting the information \nval jObj = JSONObject(jsonStr) \nval jsonArry = jObj.getJSONArray(\"users\") \nfor (i in 0 until jsonArry.length()) { \nval user = HashMap() \nval obj = jsonArry.getJSONObject(i) \nuser[\"name\"] = obj.getString(\"name\") \nuser[\"designation\"] = obj.getString(\"designation\") \nuser[\"location\"] = obj.getString(\"location\") \nuserList.add(user) \n} // ListAdapter to broadcast the information to the list elements \nval adapter: ListAdapter = SimpleAdapter( \nthis, userList, R.layout.list_row, \narrayOf(\"name\", \"designation\", \"location\"), intArrayOf( \nR.id.name, \nR.id.designation, R.id.location \n) \n) \nlv.adapter = adapter \n} catch (ex: JSONException) { \nLog.e(\"JsonParser Example\", \"unexpected JSON exception\", ex) \n} \n} // JSON object in the form of input stream \nprivate val listData: String \nget() = (\"{ \\\"users\\\" :[\" + \n\"{\\\"name\\\":\\\"Ace\\\",\\\"designation\\\":\\\"Engineer\\\",\\\"location\\\":\\\"New York\\\"}\" + \n\",{\\\"name\\\":\\\"Tom\\\",\\\"designation\\\":\\\"Director\\\",\\\"location\\\":\\\"Chicago\\\"}\" + \n\",{\\\"name\\\":\\\"Tim\\\",\\\"designation\\\":\\\"Charted Accountant\\\",\\\"location\\\":\\\"Sunnyvale\\\"}] }\") \n}Output: Run on Emulator"
},
{
"instruction": "JSON (JavaScript Object Notation) is a straightforward data exchange format to interchange the server\u2019s data, and it is a better alternative for XML. This is because JSON is a lightweight and structured language. Android supports all the JSON classes such as JSONStringer, JSONObject, JSONArray, and all other forms to parse the JSON data and fetch the required information by the program. JSON\u2019s main advantage is that it is a language-independent, and the JSON object will contain data like a key/value pair. In general, JSON nodes will start with a square bracket ([) or with a curly bracket ({). The square and curly bracket\u2019s primary difference is that the square bracket ([) represents the beginning of a JSONArray node. Whereas, the curly bracket ({) represents a JSONObject. So one needs to call the appropriate method to get the data. Sometimes JSON data start with [. We then need to use the getJSONArray() method to get the data. Similarly, if it starts with {, then we need to use the getJSONobject() method. The syntax of the JSON file is as following:\n{ \n\"Name\": \"GeeksforGeeks\", \n\"Estd\": 2009, \n\"age\": 10, \n\"address\": { \n \"buildingAddress\": \"5th & 6th Floor Royal Kapsons, A- 118\", \n \"city\": \"Sector- 136, Noida\", \n \"state\": \"Uttar Pradesh (201305)\", \n \"postalCode\": \"201305\"\n}, In this article, we are going to parse a JSON file in Android. Note that we are going toimplement this project using theKotlinlanguage.\nStep by Step Implementation\nTo parse a JSON file in Android, follow the following steps:\nStep 1: Create a New Project\nTo create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Kotlin as the programming language.\nStep 2: Working with the activity_main.xml file\nGo to the activity_main.xml file which represents the UI of the application. Create a ListView as shown. Below is the code for theactivity_main.xml file.XML \n