Missing null check in MoveGestureDetector updateMoveDistancesObjects

[felix-ht]

In rare cases the MoveGestureDetector causes and error while gestures are processed.

mapbox-gestures-android/library/src/main/java/com/mapbox/android/gestures/MoveGestureDetector.java

Line 172 in 6fc34d9

moveDistancesObjectMap.get(pointerId).addNewPosition(

This seems to be related to using Flutters Hybrid Composition

more details:
flutter-mapbox-gl/maps#975

The suggestion would be to add a null check to the offending function.

Crash Log:

E/MethodChannel#flutter/platform_views: Failed to handle method call
    java.lang.NullPointerException: Attempt to invoke virtual method 'void com.mapbox.android.gestures.MoveDistancesObject.addNewPosition(float, float)' on a null object reference
        at com.mapbox.android.gestures.MoveGestureDetector.updateMoveDistancesObjects(MoveGestureDetector.java:172)
        at com.mapbox.android.gestures.MoveGestureDetector.analyzeMovement(MoveGestureDetector.java:147)
        at com.mapbox.android.gestures.MultiFingerGesture.analyzeEvent(MultiFingerGesture.java:106)
        at com.mapbox.android.gestures.ProgressiveGesture.analyzeEvent(ProgressiveGesture.java:55)
        at com.mapbox.android.gestures.MoveGestureDetector.analyzeEvent(MoveGestureDetector.java:141)
        at com.mapbox.android.gestures.BaseGesture.analyze(BaseGesture.java:61)
        at com.mapbox.android.gestures.BaseGesture.onTouchEvent(BaseGesture.java:39)
        at com.mapbox.android.gestures.AndroidGesturesManager.onTouchEvent(AndroidGesturesManager.java:193)
        at com.mapbox.mapboxgl.MapboxMapController$1.onTouch(MapboxMapController.java:199)
        at android.view.View.dispatchTouchEvent(View.java:13479)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3082)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2767)
        at io.flutter.plugin.platform.PlatformViewsController$1.onTouch(PlatformViewsController.java:313)
        at io.flutter.embedding.engine.systemchannels.PlatformViewsChannel$1.touch(PlatformViewsChannel.java:176)
        at io.flutter.embedding.engine.systemchannels.PlatformViewsChannel$1.onMethodCall(PlatformViewsChannel.java:68)
        at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262)
        at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296)
        at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320)
        at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown Source:12)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:224)
        at android.app.ActivityThread.main(ActivityThread.java:7562)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
E/flutter: [ERROR:flutter/lib/ui/ui_dart_state.cc(209)] Unhandled Exception: PlatformException(error, Attempt to invoke virtual method 'void com.mapbox.android.gestures.MoveDistancesObject.addNewPosition(float, float)' on a null object reference, null, java.lang.NullPointerException: Attempt to invoke virtual method 'void com.mapbox.android.gestures.MoveDistancesObject.addNewPosition(float, float)' on a null object reference
        at com.mapbox.android.gestures.MoveGestureDetector.updateMoveDistancesObjects(MoveGestureDetector.java:172)
        at com.mapbox.android.gestures.MoveGestureDetector.analyzeMovement(MoveGestureDetector.java:147)
        at com.mapbox.android.gestures.MultiFingerGesture.analyzeEvent(MultiFingerGesture.java:106)
        at com.mapbox.android.gestures.ProgressiveGesture.analyzeEvent(ProgressiveGesture.java:55)
        at com.mapbox.android.gestures.MoveGestureDetector.analyzeEvent(MoveGestureDetector.java:141)
        at com.mapbox.android.gestures.BaseGesture.analyze(BaseGesture.java:61)
        at com.mapbox.android.gestures.BaseGesture.onTouchEvent(BaseGesture.java:39)
        at com.mapbox.android.gestures.AndroidGesturesManager.onTouchEvent(AndroidGesturesManager.java:193)
        at com.mapbox.mapboxgl.MapboxMapController$1.onTouch(MapboxMapController.java:199)
        at android.view.View.dispatchTouchEvent(View.java:13479)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3082)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2767)
        at io.flutter.plugin.platform.PlatformViewsController$1.onTouch(PlatformViewsController.java:313)
        at io.flutter.embedding.engine.systemchannels.PlatformViewsChannel$1.touch(PlatformViewsChannel.java:176)
        at io.flutter.embedding.engine.systemchannels.PlatformViewsChannel$1.onMethodCall(PlatformViewsChannel.java:68)
        at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:262)
        at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:296)
        at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$DartMessenger(DartMessenger.java:320)
        at io.flutter.embedding.engine.dart.-$$Lambda$DartMessenger$TsixYUB5E6FpKhMtCSQVHKE89gQ.run(Unknown Source:12)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:224)
        at android.app.ActivityThread.main(ActivityThread.java:7562)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
    )
    #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
    #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:177:18)
    <asynchronous suspension>
    #2      AndroidViewController.sendMotionEvent (package:flutter/src/services/platform_views.dart:803:5)
    <asynchronous suspension>
    #3      AndroidViewController.dispatchPointerEvent (package:flutter/src/services/platform_views.dart:895:7)
    <asynchronous suspension>

[lantah-1]

+1