Validate camera position before transforming (#9275)

* [android] - add camera position validation before transforming

* annotate CameraUpdate with nullability

2 files changed, 9 insertions, 3 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/camera/CameraUpdate.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/camera/CameraUpdate.java
index 7e0dbf08fb..498aa8343b 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/camera/CameraUpdate.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/camera/CameraUpdate.java
@@ -1,6 +1,7 @@
 package com.mapbox.mapboxsdk.camera;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import com.mapbox.mapboxsdk.maps.MapboxMap;
 
@@ -9,6 +10,7 @@ import com.mapbox.mapboxsdk.maps.MapboxMap;
  */
 public interface CameraUpdate {
 
+  @Nullable
   CameraPosition getCameraPosition(@NonNull MapboxMap mapboxMap);
 
 }
diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java
index 505e440dcb..89fbb79504 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java
@@ -93,7 +93,7 @@ final class Transform implements MapView.OnMapChangedListener {
   @UiThread
   final void moveCamera(MapboxMap mapboxMap, CameraUpdate update, MapboxMap.CancelableCallback callback) {
     CameraPosition cameraPosition = update.getCameraPosition(mapboxMap);
-    if (!cameraPosition.equals(this.cameraPosition)) {
+    if (isValidCameraPosition(cameraPosition)) {
       trackingSettings.resetTrackingModesIfRequired(this.cameraPosition, cameraPosition, false);
       cancelTransitions();
       cameraChangeDispatcher.onCameraMoveStarted(OnCameraMoveStartedListener.REASON_API_ANIMATION);
@@ -109,7 +109,7 @@ final class Transform implements MapView.OnMapChangedListener {
   final void easeCamera(MapboxMap mapboxMap, CameraUpdate update, int durationMs, boolean easingInterpolator,
                         final MapboxMap.CancelableCallback callback, boolean isDismissable) {
     CameraPosition cameraPosition = update.getCameraPosition(mapboxMap);
-    if (!cameraPosition.equals(this.cameraPosition)) {
+    if (isValidCameraPosition(cameraPosition)) {
       trackingSettings.resetTrackingModesIfRequired(this.cameraPosition, cameraPosition, isDismissable);
       cancelTransitions();
       cameraChangeDispatcher.onCameraMoveStarted(OnCameraMoveStartedListener.REASON_API_ANIMATION);
@@ -127,7 +127,7 @@ final class Transform implements MapView.OnMapChangedListener {
   final void animateCamera(MapboxMap mapboxMap, CameraUpdate update, int durationMs,
                            final MapboxMap.CancelableCallback callback) {
     CameraPosition cameraPosition = update.getCameraPosition(mapboxMap);
-    if (!cameraPosition.equals(this.cameraPosition)) {
+    if (isValidCameraPosition(cameraPosition)) {
       trackingSettings.resetTrackingModesIfRequired(this.cameraPosition, cameraPosition, false);
       cancelTransitions();
       cameraChangeDispatcher.onCameraMoveStarted(OnCameraMoveStartedListener.REASON_API_ANIMATION);
@@ -141,6 +141,10 @@ final class Transform implements MapView.OnMapChangedListener {
     }
   }
 
+  private boolean isValidCameraPosition(@Nullable CameraPosition cameraPosition) {
+    return cameraPosition != null && !cameraPosition.equals(this.cameraPosition);
+  }
+
   @UiThread
   @Nullable
   CameraPosition invalidateCameraPosition() {