piotrprus / motionlayoutplayground Goto Github PK

Hey,

Here's the stack trace of the crash I get when playing around with the recyclerview and some animations :

2019-12-03 13:06:52.856 20493-20493/com.piotrprus.motionlayoutplayground E/AndroidRuntime: FATAL EXCEPTION: main Process: com.piotrprus.motionlayoutplayground, PID: 20493 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.VelocityTracker.addMovement(android.view.MotionEvent)' on a null object reference at androidx.constraintlayout.motion.widget.MotionLayout$MyTracker.addMovement(MotionLayout.java:985) at androidx.constraintlayout.motion.widget.MotionScene.processTouchEvent(MotionScene.java:1043) at androidx.constraintlayout.motion.widget.MotionLayout.onTouchEvent(MotionLayout.java:2992) at android.view.View.dispatchTouchEvent(View.java:10023) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2626) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2307) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2632) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2264) at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:413) at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1808) at android.app.Activity.dispatchTouchEvent(Activity.java:3061) at androidx.appcompat.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69) at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:375) at android.view.View.dispatchPointerEvent(View.java:10243) at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4438) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4306) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3853) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3906) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3872) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3999) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3880) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4056) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3853) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3906) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3872) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3880) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3853) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6246) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6220) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6181) at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6349) at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185) at android.os.MessageQueue.nativePollOnce(Native Method) at android.os.MessageQueue.next(MessageQueue.java:323) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:6119) 2019-12-03 13:06:52.856 20493-20493/com.piotrprus.motionlayoutplayground E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

I got the same crash on my test app when I play too much with the recyclerView and the animations. I've also disabled touchEvent on the recyclerView when the animation starts and puts it back when the animation finishes ( but in a less clean way). So far, I guess the problem comes from the motionLayout view being null/deleted/not detected for some reason after an animation.

PS : The crash mainly occurs when I try to scroll the list after I've executed an animation.

I hope it helps!