Draw Marker, mNativeMapView NullPointerException

[BrunoDrean]

Hello,

I integrated MapBox 4.0.1 in my mobile app, It's an navigation application like Waze for example.

I've a problem in a particular case : the user click on the back button (onBackPressed was called) when MapBox drawing a Markers on a Map.

The NullPointer Exception is generated here : mapboxMap.addMarker(op);

but looking closer the StrackTrace, we notice (MapView.java:988)

return mNativeMapView.addMarker(marker);

I Think that when the user "onBackPressed" the object "mNativeMapView" becomes "null"

here is the code in question :

mapView.getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(MapboxMap mapboxMap) {
            [..]
                        if (mapboxMap != null) {
                            MarkerOptions op = new MarkerOptions().position(...).title(...).icon(...);
                            mapboxMap.addMarker(op);                           
                        }
            [..]
            }           
}

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'long com.mapbox.mapboxsdk.maps.NativeMapView.addMarker(com.mapbox.mapboxsdk.annotations.Marker)' on a null object reference
       at com.mapbox.mapboxsdk.maps.MapView.addMarker(MapView.java:988)
       at com.mapbox.mapboxsdk.maps.MapboxMap.addMarker(MapboxMap.java:591)
       at com.mapbox.mapboxsdk.maps.MapboxMap.addMarker(MapboxMap.java:574)
       at fr.agemos.labbe.android.controller.MapBoxActivity$5.onMapReady(MapBoxActivity.java:1370)
       at com.mapbox.mapboxsdk.maps.MapView.getMapAsync(MapView.java:2442)
       at fr.agemos.labbe.android.controller.MapBoxActivity.drawBridges(MapBoxActivity.java:1327)
       at fr.agemos.labbe.android.controller.MapBoxActivity.resultOverPassAsyncTask(MapBoxActivity.java:1913)
       at fr.agemos.labbe.android.service.asynctask.AsyncTaskOverPass.onPostExecute(AsyncTaskOverPass.java:161)
       at fr.agemos.labbe.android.service.asynctask.AsyncTaskOverPass.onPostExecute(AsyncTaskOverPass.java:29)
       at android.os.AsyncTask.finish(AsyncTask.java:632)
       at android.os.AsyncTask.access$600(AsyncTask.java:177)
       at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:145)
       at android.app.ActivityThread.main(ActivityThread.java:6066)
       at java.lang.reflect.Method.invoke(Method.java)
       at java.lang.reflect.Method.invoke(Method.java:372)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1388)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1183)

Thanks in advance for your help,

[tobrun]

@NonowPoney
Thank you for reaching out and reporting your issue.

The underlying code for addMarker is:

    long addMarker(@NonNull Marker marker) {
        return mNativeMapView.addMarker(marker);
    }

It's not incorporating the check to validate if the underlying mNativeMapView has been destroyed:

For example:

 long addPolyline(@NonNull Polyline polyline) {
        if (mDestroyed) {
            return 0l;
        }
        return mNativeMapView.addPolyline(polyline);
 }

[tobrun]

@bleege suggesting to put this on the 4.1.0 milestone. This solves the edge case of crashing if a marker is being added when the hosting Activity is being destroyed. Code can be viewed in 964a6cd and PR created in #5150.

[Schumi09]

The same exception is thrown if you add a marker while the screen orientation changes.

[bleege]

@tobrun Sounds good to me. Let's redo the PR to get it onto the 4.1.0 Release Branch instead of master though.

[bleege]

@tobrun Actually with the time difference and it being Memorial Day weekend I'll just merge this fix into master now and then cherry pick it over to the release branch. This will make this fix available sooner for everyone. I'll take care of this now.

[bleege]

Rebased and Merged to master

[bleege]

Cherry picked to release-android-v4.1.0. I'm going to start a new SNAPSHOT build so this (along with the other changes from today) will be available within an hour or so.

[BrunoDrean]

Thank you for your help !