Select platform: [Android](https://developers.google.com/maps/documentation/android-sdk/dds-boundaries/handle-events.md.txt "View this page for the Android platform docs.") [iOS](https://developers.google.com/maps/documentation/ios-sdk/dds-boundaries/handle-events.md.txt "View this page for the iOS platform docs.") [JavaScript](https://developers.google.com/maps/documentation/javascript/dds-boundaries/handle-events.md.txt "View this page for the JavaScript platform docs.")

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You can make a feature layer respond to user `click` events to get the place
ID and feature type for the boundary that was clicked. The
following example map shows the boundaries for the Country layer, and
shows an event handler that styles the clicked polygon associated with the
selected country.

## Write a click event handler

When a click event occurs on a feature layer, the Maps SDK for Android passes a
[`FeatureClickEvent`](https://developers.google.com/android/reference/com/google/android/gms/maps/model/FeatureClickEvent.md.txt)
object to the event handler. Use the `FeatureClickEvent` to get the latitude
and longitude coordinates of the click and a list of features affected by the
click.

## Handle feature layer events

Take the following steps to handle events on a feature layer. In this example,
you define a click event handler for the Country feature layer to apply a red
fill to the polygon representing the selected country.

When you call
[`FeatureLayer.setFeatureStyle()`](https://developers.google.com/android/reference/com/google/android/gms/maps/model/FeatureLayer.md.txt#setFeatureStyle(com.google.android.gms.maps.model.FeatureLayer.StyleFactory)),
the style factory function sets the style on all features in the
feature layer. To update the style of a feature in the event handler, you must
call `FeatureLayer.setFeatureStyle()` to set the updated style on all
features.

1. If you haven't already done so, follow the steps in
   [Get Started](https://developers.google.com/maps/documentation/android/dds-boundaries/start)
   to create a new map ID and map style. Be sure to enable the **Country**
   feature layer.

2. Make sure your class implements
   [`FeatureLayer.OnFeatureClickListener`](https://developers.google.com/android/reference/com/google/android/gms/maps/model/FeatureLayer.OnFeatureClickListener.md.txt).

3. Register an event handler for feature click events by calling
   [`FeatureLayer.addOnFeatureClickListener()`](https://developers.google.com/android/reference/com/google/android/gms/maps/model/FeatureLayer.md.txt#addOnFeatureClickListener(com.google.android.gms.maps.model.FeatureLayer.OnFeatureClickListener)).

   ### Java


   ```java
   private FeatureLayer countryLayer;

   @Override
   public void onMapReady(GoogleMap map) {

     // Get the COUNTRY feature layer.
     countryLayer = map.getFeatureLayer(new FeatureLayerOptions.Builder()
       .featureType(FeatureType.COUNTRY)
       .build());

     // Register the click event handler for the Country layer.
     countryLayer.addOnFeatureClickListener(this);

     // Apply default style to all countries on load to enable clicking.
     styleCountryLayer();
   }

   // Set default fill and border for all countries to ensure that they respond
   // to click events.
   private void styleCountryLayer() {
     FeatureLayer.StyleFactory styleFactory = (Feature feature) -> {
       return new FeatureStyle.Builder()
         // Set the fill color for the country as white with a 10% opacity.
         .fillColor(Color.argb(0.1, 0, 0, 0))
         // Set border color to solid black.
         .strokeColor(Color.BLACK)
         .build();
     };

     // Apply the style factory function to the country feature layer.
     countryLayer.setFeatureStyle(styleFactory);
   }
   ```

   <br />

   ### Kotlin


   ```java
   private var countryLayer: FeatureLayer? = null

   override fun onMapReady(googleMap: GoogleMap) {
     // Get the COUNTRY feature layer.
     countryLayer = googleMap.getFeatureLayer(FeatureLayerOptions.Builder()
       .featureType(FeatureType.COUNTRY)
       .build())

     // Register the click event handler for the Country layer.
     countryLayer?.addOnFeatureClickListener(this)

     // Apply default style to all countries on load to enable clicking.
     styleCountryLayer()
   }

   // Set default fill and border for all countries to ensure that they respond
   // to click events.
   private fun styleCountryLayer() {
     val styleFactory = FeatureLayer.StyleFactory { feature: Feature ->
       return@StyleFactory FeatureStyle.Builder()
         // Set the fill color for the country as white with a 10% opacity.
         .fillColor(Color.argb(0.1f, 0f, 0f, 0f))
         // Set border color to solid black.
         .strokeColor(Color.BLACK)
         .build()
     }

     // Apply the style factory function to the country feature layer.
     countryLayer?.setFeatureStyle(styleFactory)
   }
   ```

   <br />

4. Apply a fill color of red to the selected country. Only visible features are
   clickable.

   ### Java


   ```java
   @Override
   // Define the click event handler.
   public void onFeatureClick(FeatureClickEvent event) {

     // Get the list of features affected by the click using
     // getPlaceIds() defined below.
     List<String> selectedPlaceIds = getPlaceIds(event.getFeatures());

     if (!selectedPlaceIds.isEmpty()) {
       FeatureLayer.StyleFactory styleFactory = (Feature feature) -> {
         // Use PlaceFeature to get the placeID of the country.
         if (feature instanceof PlaceFeature) {
           if (selectedPlaceIds.contains(((PlaceFeature) feature).getPlaceId())) {
             return new FeatureStyle.Builder()
                 // Set the fill color to red.
                 .fillColor(Color.RED)
                 .build();
           }
         }
         return null;
       };

       // Apply the style factory function to the feature layer.
       countryLayer.setFeatureStyle(styleFactory);
     }
   }

   // Get a List of place IDs from the FeatureClickEvent object.
   private List<String> getPlaceIds(List<Feature> features) {
     List<String> placeIds = new ArrayList<>();
     for (Feature feature : features) {
       if (feature instanceof PlaceFeature) {
           placeIds.add(((PlaceFeature) feature).getPlaceId());
       }
     }
     return placeIds;
   }
   ```

   <br />

   ### Kotlin


   ```java
   // Define the click event handler.
   override fun onFeatureClick(event: FeatureClickEvent) {

     // Get the list of features affected by the click using
     // getPlaceIds() defined below.
     val selectedPlaceIds = getPlaceIds(event.getFeatures())
     if (!selectedPlaceIds.isEmpty()) {
         val styleFactory = FeatureLayer.StyleFactory { feature: Feature ->
             // Use PlaceFeature to get the placeID of the country.
             if (feature is PlaceFeature) {
                 if (selectedPlaceIds.contains((feature as PlaceFeature).getPlaceId())) {
                     return@StyleFactory FeatureStyle.Builder()
                         // Set the fill color to red.
                         .fillColor(Color.RED)
                         .build()
                 }
             }
             return@StyleFactory null
         }

         // Apply the style factory function to the feature layer.
         countryLayer?.setFeatureStyle(styleFactory)
     }
   }

   // Get a List of place IDs from the FeatureClickEvent object.
   private fun getPlaceIds(features: List<Feature>): List<String> {
     val placeIds: MutableList<String> = ArrayList()
     for (feature in features) {
         if (feature is PlaceFeature) {
             placeIds.add((feature as PlaceFeature).getPlaceId())
         }
     }
     return placeIds
   }
   ```

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