Why would onTouch() generate FATAL EXCEPTION when returning false?
I wrote a simple MotionEvent exercise in which all I do is log the parameters of the event. I do that by implementing OnTouchListener and overriding onTouch() in the main activity.
For one button, I return true at the end of onTouch(). No problems there.
For another button, I return false at the end of onTouch(). This is where it gets interesting. By mere returning 'false', a FATAL EXCEPTION is thrown with a tiny hint which I don't really understand: "recycled twice!".
What does this mean?
Update: per the suggestion in the comment below, I am adding the details of the exception from LogCat:
03-08 10:35:14.275: ERROR/AndroidRuntime(521): FATAL EXCEPTION: main
03-08 10:35:14.275: ERROR/AndroidRuntime(521): java.lang.RuntimeException: MotionEvent{405215b0 action=0 x=66.0 y=78.0 pressure=1.0 size=0.0} recycled twice!
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at android.view.MotionEvent.recycle(MotionEvent.java:659)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at android.view.ViewRoot.handleMessage(ViewRoot.java:1880)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at android.os.Looper.loop(Looper.java:123)
03-08 10:35:14.275: ERROR/And开发者_如何学运维roidRuntime(521): at android.app.ActivityThread.main(ActivityThread.java:3647)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at java.lang.reflect.Method.invoke(Method.java:507)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-08 10:35:14.275: ERROR/AndroidRuntime(521): at dalvik.system.NativeStart.main(Native Method)
Are you recycling and then passing false
?
The framework will assume that the MotionEvent is still valid if you return false and will do its own processing with it.
From the docs:
Recycle the MotionEvent, to be re-used by a later caller. After calling this function you must not ever touch the event again.
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