调用 ParallaxHelper.enableParallaxBack 时跳转Activity可能会导致崩溃

[seasonyuu]

java.lang.NullPointerException: Attempt to read from null array
        at com.github.anzewei.parallaxbacklayout.ViewDragHelper.shouldInterceptTouchEvent(ViewDragHelper.java:1115)
        at com.github.anzewei.parallaxbacklayout.widget.ParallaxBackLayout.onInterceptTouchEvent(ParallaxBackLayout.java:160)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2515)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2974)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2661)
        at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:549)
        at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1953)
        at android.app.Activity.dispatchTouchEvent(Activity.java:3559)
        at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
        at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:502)
        at android.view.View.dispatchPointerEvent(View.java:12027)
        at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:5278)
        at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5067)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4581)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4634)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4600)
        at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4727)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4608)
        at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4784)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4581)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4634)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4600)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4608)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4581)
        at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:7169)
        at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:7143)
        at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:7104)
        at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:7325)
        at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:192)
        at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
        at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:181)
        at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:7248)
        at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:7353)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:981)
        at android.view.Choreographer.doCallbacks(Choreographer.java:790)
        at android.view.Choreographer.doFrame(Choreographer.java:715)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:967)
        at android.os.Handler.handleCallback(Handler.java:808)
        at android.os.Handler.dispatchMessage(Handler.java:101)
        at android.os.Looper.loop(Looper.java:166)
        at android.app.ActivityThread.main(ActivityThread.java:7529)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)