Crash Inside MapView When Calling OnStop() Before Map is Fully Initialized

[simon1867]

Platform: Android
Mapbox SDK version: 5.2.0 beta 1

In my case I have a fragment that shows the user a map of where they are. On Android Api 23 or higher I have to ask the user for permission to get their location. In that scenario I don't load the map until they give me permission and I get the location. I'm running across a race condition when the user agrees to the permission I load the fragment with the map, while it in the middle of loading, I replace the fragment with another one triggered by a location update callback. OnStop() gets called on the first fragment and MapView which throws a null pointer because it hasn't finished with the async map setup.

  public void onStop() {
    mapboxMap.onStop();
    ConnectivityReceiver.instance(getContext()).deactivate();
  }

In my case mapboxMap was null.

I called onStop() from within a try catch to silence the error.
After doing that and replicating the scenario I got a crash inside of onDetachedFromWindow()

  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    mapZoomButtonController.setVisible(false);
  }

mapZoomButtonController was null.

I went ahead a extended MapView in which I override onDetachedFromWindow() and call the super from within a try catch.
After that, initialiseDrawingSurface() inside of MapView throws this exception:

java.lang.IllegalStateException: setRenderer has already been called for this instance.
at android.opengl.GLSurfaceView.checkRenderThreadState(GLSurfaceView.java:1934)
at android.opengl.GLSurfaceView.setEGLContextClientVersion(GLSurfaceView.java:578)
at com.mapbox.mapboxsdk.maps.MapView.initialiseDrawingSurface(MapView.java:291)
at com.mapbox.mapboxsdk.maps.MapView.access$100(MapView.java:68)
at com.mapbox.mapboxsdk.maps.MapView$1.onGlobalLayout(MapView.java:141)
at android.view.ViewTreeObserver.dispatchOnGlobalLayout(ViewTreeObserver.java:982)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2461)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1488)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7451)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920)
at android.view.Choreographer.doCallbacks(Choreographer.java:695)
at android.view.Choreographer.doFrame(Choreographer.java:631)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Steps to trigger behavior

1. Navigate to an activity with a fragment that has a map
2. Shortly after adding the fragment replace it with another fragment with a map
3. Crash

[simon1867]

I ended up preventing the crash by throttling my callback so that I don't replace my fragment before the map on the previous fragment is already loaded.

[tobrun]

@simon-the-canadian thank you for the report: will look into hardening the onStop invocaton, the mapZoomButton controller has recently been fixed with:

  @Override
  @CallSuper
  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    if (isZoomButtonControllerInitialized()) {
      mapZoomButtonController.setVisible(false);
    }
  }

[tobrun]

fixed with #10259