first select dataset, than model. do not enable metric selection if no models selected

app.py

@@ -177,9 +177,6 @@ assert len(set(model_display_names)) == len(model_display_names), "Model display
 assert len(set(metric_display_names)) == len(metric_display_names), "Metric display names are not unique"
 assert len(set(viz_display_names)) == len(viz_display_names), "Viz display names are not unique"
 
-selected_model_names = st.multiselect('Select multiple methods to compare', model_display_names)
-selected_models = [model for model in models if model['display_name'] in selected_model_names]
-
 col1, col2 = st.columns(2)
 
 with col1:
@@ -189,10 +186,21 @@ with col1:
 with col2:
     selected_sequence = st.selectbox('Select sequence', options=selected_dataset["sequences"].keys())
 
+selected_model_names = st.multiselect('Select multiple methods to compare', model_display_names)
+selected_models = [model for model in models if model['display_name'] in selected_model_names]
+
+disable_metrics = len(selected_models) == 0
+
+if disable_metrics:
+    tooltip_str = "Select at least one method to enable metric selection"
+else:
+    tooltip_str = ""
+
 usable_metrics = [metric for metric in metrics if metric['no_ref'] == selected_dataset['no_ref']]
 usable_metric_display_names = get_display_names(usable_metrics)
 
-selected_metric_names = st.multiselect('Select metrics to display', usable_metric_display_names)
+selected_metric_names = st.multiselect('Select metrics to display', usable_metric_display_names,
+                                       disabled=disable_metrics, help=tooltip_str)
 selected_metrics = [metric for metric in usable_metrics if metric['display_name'] in selected_metric_names]
 
 if not selected_dataset['has_frames']: