NPE in TouchGestureHandler

[wojtek-abakus]

Hello. I found an error in TouchGestureHandler in automatic Google logs. It happens approx 2 times a day in a 10000 users app.

java.lang.NullPointerException: at org.mapsforge.map.android.input.TouchGestureHandler.onSingleTapConfirmed (TouchGestureHandler.java:232) at android.view.GestureDetector$GestureHandler.handleMessage (GestureDetector.java:312) at android.os.Handler.dispatchMessage (Handler.java:102) at android.os.Looper.loop (Looper.java:158) at android.app.ActivityThread.main (ActivityThread.java:7224) at java.lang.reflect.Method.invoke (Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:1230) at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1120)

In my opinion a touch event can move through the event queue after the fragment with map is changed and MapView's destroy method called (which nulls layerManager)

Could you please change the 231 line in TouchGestureHandler from
if (tapLatLong != null) {
to
if (tapLatLong != null && this.mapView.getLayerManager() != null) {

[devemux86]

Can check the LayerManager at start of both onLongPress and onSingleTapConfirmed methods in TouchGestureHandler.

Or better revert the nullify of LayerManager in MapView.destroy, introduced in #845, as doesn't seem to improve something there.

[devemux86]

I reverted the nullify of LayerManager in MapView.destroy, introduced in #845.