NullPointerException: Attempt to read from null array

How it happens?
---java.lang.NullPointerException: Attempt to read from null array
android.support.v4.widget.ViewDragHelper.processTouchEvent(1160)
...myproject.SwipeLayout.onTouchEvent(990)
android.view.View.dispatchTouchEvent(9019)
android.view.ViewGroup.dispatchTransformedTouchEvent(2701)
android.view.ViewGroup.dispatchTouchEvent(2413)
android.view.ViewGroup.dispatchTransformedTouchEvent(2712)
android.view.ViewGroup.dispatchTouchEvent(2428)
android.view.ViewGroup.dispatchTransformedTouchEvent(2712)
android.view.ViewGroup.dispatchTouchEvent(2428)
android.view.ViewGroup.dispatchTransformedTouchEvent(2712)
android.view.ViewGroup.dispatchTouchEvent(2428)
android.view.ViewGroup.dispatchTransformedTouchEvent(2712)
android.view.ViewGroup.dispatchTouchEvent(2428)
com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(2678)
com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(1797)
android.app.Activity.dispatchTouchEvent(2878)
xxx.BaseActivity.dispatchTouchEvent(2042)
com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(2639)
android.view.View.dispatchPointerEvent(9224)
android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(4813)
android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(4651)
android.view.ViewRootImpl$InputStage.deliver(4202)
android.view.ViewRootImpl$InputStage.onDeliverToNext(4255)
android.view.ViewRootImpl$InputStage.forward(4221)
android.view.ViewRootImpl$AsyncInputStage.forward(4331)
android.view.ViewRootImpl$InputStage.apply(4229)
android.view.ViewRootImpl$AsyncInputStage.apply(4388)
android.view.ViewRootImpl$InputStage.deliver(4202)
android.view.ViewRootImpl$InputStage.onDeliverToNext(4255)
android.view.ViewRootImpl$InputStage.forward(4221)
android.view.ViewRootImpl$InputStage.apply(4229)
android.view.ViewRootImpl$InputStage.deliver(4202)
android.view.ViewRootImpl.deliverInputEvent(6674)
android.view.ViewRootImpl.doProcessInputEvents(6567)
android.view.ViewRootImpl.enqueueInputEvent(6538)
android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(6764)
android.view.InputEventReceiver.dispatchInputEvent(185)
android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(-2)
android.view.InputEventReceiver.consumeBatchedInputEvents(176)
android.view.ViewRootImpl.doConsumeBatchedInput(6735)
android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(6787)
android.view.Choreographer$CallbackRecord.run(777)
android.view.Choreographer.doCallbacks(590)
android.view.Choreographer.doFrame(558)
android.view.Choreographer$FrameDisplayEventReceiver.run(763)
android.os.Handler.handleCallback(739)
android.os.Handler.dispatchMessage(95)
android.os.Looper.loop(145)
android.app.ActivityThread.main(6145)
java.lang.reflect.Method.invoke(-2)
java.lang.reflect.Method.invoke(372)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(1399)
com.android.internal.os.ZygoteInit.main(1194)