MarkerView more robust when updates are asynchronous (#6717)

* [android] - remove ViewMarkers crash, show correct view cache size in test activity

* use MapboxMap to indicate a MarkerView is no longer added on a map, no future updates will be passed on to core.

* resolve memory leak

3 files changed, 21 insertions, 19 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerView.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerView.java
index 5c84fb9992..b41eebff09 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerView.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerView.java
@@ -345,19 +345,23 @@ public class MarkerView extends Marker {
      * <p>
      * This method is used to instantiate the MarkerView and provide an instance of {@link com.mapbox.mapboxsdk.maps.MapboxMap.MarkerViewAdapter}
      * </p>
+     * <p>
+     * This method is used to notify that a MarkerView is no longer active by setting a null value.
+     * </p>
      *
      * @param mapboxMap the MapboxMap instances
      */
     @Override
     public void setMapboxMap(MapboxMap mapboxMap) {
         super.setMapboxMap(mapboxMap);
+        if(mapboxMap!=null) {
+            if (isFlat()) {
+                // initial tilt value if MapboxMap is started with a tilt attribute
+                tiltValue = (float) mapboxMap.getCameraPosition().tilt;
+            }
 
-        if (isFlat()) {
-            // initial tilt value if MapboxMap is started with a tilt attribute
-            tiltValue = (float) mapboxMap.getCameraPosition().tilt;
+            markerViewManager = mapboxMap.getMarkerViewManager();
         }
-
-        markerViewManager = mapboxMap.getMarkerViewManager();
     }
 
     /**
diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerViewManager.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerViewManager.java
index fe1a48993b..ded3130715 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerViewManager.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/MarkerViewManager.java
@@ -317,6 +317,7 @@ public class MarkerViewManager {
                 }
             }
         }
+        marker.setMapboxMap(null);
         markerViewMap.remove(marker);
     }
 
@@ -390,14 +391,15 @@ public class MarkerViewManager {
         // remove old markers
         Iterator<MarkerView> iterator = markerViewMap.keySet().iterator();
         while (iterator.hasNext()) {
-            MarkerView m = iterator.next();
-            if (!markers.contains(m)) {
+            MarkerView marker = iterator.next();
+            if (!markers.contains(marker)) {
                 // remove marker
-                convertView = markerViewMap.get(m);
+                convertView = markerViewMap.get(marker);
                 for (MapboxMap.MarkerViewAdapter adapter : markerViewAdapters) {
-                    if (adapter.getMarkerClass().equals(m.getClass())) {
-                        adapter.prepareViewForReuse(m, convertView);
+                    if (adapter.getMarkerClass().equals(marker.getClass())) {
+                        adapter.prepareViewForReuse(marker, convertView);
                         adapter.releaseView(convertView);
+                        marker.setMapboxMap(null);
                         iterator.remove();
                     }
                 }
@@ -409,20 +411,14 @@ public class MarkerViewManager {
             if (!markerViewMap.containsKey(marker)) {
                 for (final MapboxMap.MarkerViewAdapter adapter : markerViewAdapters) {
                     if (adapter.getMarkerClass().equals(marker.getClass())) {
+
+                        // Inflate View
                         convertView = (View) adapter.getViewReusePool().acquire();
                         final View adaptedView = adapter.getView(marker, convertView, mapView);
                         if (adaptedView != null) {
-
-                            // tilt
                             adaptedView.setRotationX(marker.getTilt());
-
-                            // rotation
                             adaptedView.setRotation(marker.getRotation());
-
-                            // alpha
                             adaptedView.setAlpha(marker.getAlpha());
-
-                            // visible
                             adaptedView.setVisibility(View.GONE);
 
                             if (mapboxMap.getSelectedMarkers().contains(marker)) {
@@ -448,6 +444,7 @@ public class MarkerViewManager {
                                 }
                             });
 
+                            marker.setMapboxMap(mapboxMap);
                             markerViewMap.put(marker, adaptedView);
                             if (convertView == null) {
                                 adaptedView.setVisibility(View.GONE);
diff --git a/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/annotation/MarkerViewActivity.java b/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/annotation/MarkerViewActivity.java
index 8d678794c4..fe20b75a8d 100644
--- a/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/annotation/MarkerViewActivity.java
+++ b/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/annotation/MarkerViewActivity.java
@@ -146,7 +146,7 @@ public class MarkerViewActivity extends AppCompatActivity {
                     public void onMapChanged(@MapView.MapChange int change) {
                         if (change == MapView.REGION_IS_CHANGING || change == MapView.REGION_DID_CHANGE) {
                             if (!markerViewManager.getMarkerViewAdapters().isEmpty() && viewCountView != null) {
-                                viewCountView.setText("ViewCache size " + (mapView.getChildCount() - 5));
+                                viewCountView.setText("ViewCache size " + mapView.getMarkerViewContainer().getChildCount());
                             }
                         }
                     }
@@ -194,6 +194,7 @@ public class MarkerViewActivity extends AppCompatActivity {
     protected void onStop() {
         super.onStop();
         locationUpdateHandler.removeCallbacks(moveMarkerRunnable);
+        rotateUpdateHandler.removeCallbacks(rotateMarkerRunnable);
     }
 
     /**