Nexus7除右滑外，所有滑动结束后均fc

[Bayonetta]

附上log：

---

09-05 21:25:47.061 11676-11676/me.imid.swipebacklayout.demo E/AndroidRuntime: FATAL EXCEPTION: main java.lang.NullPointerException at android.view.GLES20RenderLayer.redrawLater(GLES20RenderLayer.java:121) at android.view.View.getHardwareLayer(View.java:12592) at android.view.View.getDisplayList(View.java:12804) at android.view.View.getDisplayList(View.java:12880) at android.view.View.draw(View.java:13657) at android.view.ViewGroup.drawChild(ViewGroup.java:3083) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2920) at android.view.View.getDisplayList(View.java:12833) at android.view.View.getDisplayList(View.java:12880) at android.view.HardwareRenderer$GlRenderer.buildDisplayList(HardwareRenderer.java:1411) at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:1359) at android.view.ViewRootImpl.draw(ViewRootImpl.java:2367) at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2239) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1872) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) at android.view.Choreographer.doCallbacks(Choreographer.java:562) at android.view.Choreographer.doFrame(Choreographer.java:532) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) at android.os.Handler.handleCallback(Handler.java:730) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5103) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) at dalvik.system.NativeStart.main(Native Method)

[mariotaku]

comment out following lines in SwipeBackLayout$ViewDragCallback.onViewDragStateChanged(int)

    if (state == ViewDragHelper.STATE_IDLE) {
        ViewCompat.setLayerType(SwipeBackLayout.this, ViewCompat.LAYER_TYPE_NONE, null);
    } else if (state == ViewDragHelper.STATE_SETTLING) {
        ViewCompat.setLayerType(SwipeBackLayout.this, ViewCompat.LAYER_TYPE_HARDWARE, null);
    }

[ikew0ng]

fixed