Do not take snapshot if map is stopped. (#390)

MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java

@@ -81,6 +81,7 @@ public final class MapboxMap {
   private Style style;
 
   private boolean debugActive;
+  private boolean started;
 
   MapboxMap(NativeMap map, Transform transform, UiSettings ui, Projection projection,
             OnGesturesManagerInteractionListener listener, CameraChangeDispatcher cameraChangeDispatcher,
@@ -143,6 +144,7 @@ public final class MapboxMap {
    * Called when the hosting Activity/Fragment onStart() method is called.
    */
   void onStart() {
+    started = true;
     locationComponent.onStart();
   }
 
@@ -150,6 +152,7 @@ public final class MapboxMap {
    * Called when the hosting Activity/Fragment onStop() method is called.
    */
   void onStop() {
+    started = false;
     locationComponent.onStop();
   }
 
@@ -2003,6 +2006,9 @@ public final class MapboxMap {
    * @param callback Callback method invoked when the snapshot is taken.
    */
   public void snapshot(@NonNull SnapshotReadyCallback callback) {
+    if (!started) {
+      return;
+    }
     nativeMapView.addSnapshotCallback(callback);
   }
 

MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/GLSurfaceRecyclerViewActivity.kt

@@ -6,7 +6,6 @@ import android.view.LayoutInflater
 import android.view.ViewGroup
 import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
-import androidx.recyclerview.widget.RecyclerView
 import com.mapbox.mapboxsdk.maps.MapView
 import com.mapbox.mapboxsdk.maps.Style
 import com.mapbox.mapboxsdk.testapp.R
@@ -141,7 +140,11 @@ open class GLSurfaceRecyclerViewActivity : AppCompatActivity() {
       }
 
       fun bind(mapItem: MapItem) {
-        mapView.getMapAsync { mapboxMap -> mapboxMap.setStyle(mapItem.style) }
+        mapView.getMapAsync { mapboxMap ->
+          mapboxMap.setStyle(mapItem.style) {
+            mapboxMap.snapshot { }
+          }
+        }
       }
     }