good point. Thanks Romain. :)
On Mar 31, 5:37 pm, Romain Guy <romain...@google.com> wrote:
> No because the issue is in VelocityTracker :)
>
>
>
> On Tue, Mar 31, 2009 at 4:39 PM, focuser <linto...@gmail.com> wrote:
>
> > Great!
>
> > Will it fix the problem in my app if I pull GestureDetector.java from
> > Cupcake and include/use it in my code?
>
> > On Mar 31, 4:05 pm, Romain Guy <romain...@google.com> wrote:
> >> The problem comes from the VelocityTracker used by the
> >> GestureDetector. The tracker has a pool of 1 instance but there's a
> >> bug in the pool management which causes both your GestureDetector and
> >> ListView to use the *same* VelocityTracker. This means the tracker
> >> receives most events twice.
>
> >> I just fixed this issue in Cupcake.
>
> >> On Tue, Mar 31, 2009 at 4:01 PM, focuser <linto...@gmail.com> wrote:
>
> >> > OK, but could you explain briefly why the GestureDetector would have
> >> > such side effect? In the code above I don't see any events being
> >> > stolen nor any new events being created. Original events are just
> >> > passed to FrameLayout.dispatchTouchEvent as if there's no
> >> > GestureDetector used.
>
> >> > I even tried the following but it makes no difference.
> >> > public boolean dispatchTouchEvent(MotionEvent ev) {
> >> > MotionEvent oldEv = ev.obtain();
> >> > boolean handled = mGestureDetector.onTouchEvent(ev);
> >> > return super.dispatchTouchEvent(oldEv);
> >> > }
>
> >> > On Mar 31, 12:07 pm, Romain Guy <romain...@google.com> wrote:
> >> >> Unfortunately I don't see any possible workaround :(
>
> >> >> On Tue, Mar 31, 2009 at 11:40 AM, focuser <linto...@gmail.com> wrote:
>
> >> >> > Thanks Romain,
>
> >> >> > I have just filed
> >> >> > ithttp://code.google.com/p/android/issues/detail?id=2337.
>
> >> >> > But before it's fixed in a new release, is there any workaround or I
> >> >> > will have to play with the VelocityTracker myself?
>
> >> >> > On Mar 31, 10:39 am, Romain Guy <romain...@google.com> wrote:
> >> >> >> Hi,
>
> >> >> >> It looks like a bug in the VelocityTracker. Can you please file it at
> >> >> >> b.android.com? Thanks
>
> >> >> >> On Tue, Mar 31, 2009 at 10:28 AM, focuser <linto...@gmail.com> wrote:
>
> >> >> >> > Hi,
>
> >> >> >> > I'm trying to use a GestureDetector in a subclass of FrameLayout,
> >> >> >> > which has a child ListView.
> >> >> >> > But it seems the GestureDetector has some side effect which causes
> >> >> >> > abnormal scrolling behaviors for the child ListView, e.g. sometime
> >> >> >> > when flinging down, the list actually scrolls upwards; when the
> >> >> >> > list
> >> >> >> > is being flung (i.e. the scrolling animation is still playing) and
> >> >> >> > you
> >> >> >> > press and hold on the list, the scroling stops (which is normal),
> >> >> >> > but
> >> >> >> > as soon as you release, the list scrolls.
>
> >> >> >> > The code for the layout is shown below. Apparently it actually
> >> >> >> > does
> >> >> >> > nothing extra but calling GestureDetector.onTouchEvent(). If the
> >> >> >> > line
> >> >> >> > "boolean handled = mGestureDetector.onTouchEvent(ev);" is commented
> >> >> >> > out, the child ListView will scroll as normal. Is it because the
> >> >> >> > call
> >> >> >> > to onTouchEvent() takes some time that confuses the child ListView?
>
> >> >> >> > Also, it seems this problem only occurs when the list item is
> >> >> >> > complex,
> >> >> >> > e.g. consisting of multiple ImageViews, TextView etc. Everything
> >> >> >> > works fine if it's just a list of TextView's.
>
> >> >> >> > public class MyLayout extends FrameLayout implements
> >> >> >> > OnGestureListener
> >> >> >> > {
> >> >> >> > ...
> >> >> >> > �...@override
> >> >> >> > public boolean dispatchTouchEvent(MotionEvent ev) {
> >> >> >> > boolean handled = mGestureDetector.onTouchEvent(ev);
> >> >> >> > return super.dispatchTouchEvent(ev);
> >> >> >> > }
>
> >> >> >> > public void onShowPress(MotionEvent e) {
> >> >> >> > }
>
> >> >> >> > public boolean onSingleTapUp(MotionEvent e) {
> >> >> >> > return false;
> >> >> >> > }
>
> >> >> >> > public void onLongPress(MotionEvent e) {
> >> >> >> > }
>
> >> >> >> > public boolean onDown(MotionEvent e) {
> >> >> >> > return false;
> >> >> >> > }
>
> >> >> >> > public boolean onFling(MotionEvent e1, MotionEvent e2, float
> >> >> >> > velocityX,
> >> >> >> > float velocityY) {
> >> >> >> > return false;
> >> >> >> > }
>
> >> >> >> > public boolean onScroll(MotionEvent e1, MotionEvent e2,
> >> >> >> > float
> >> >> >> > distanceX,
> >> >> >> > float distanceY) {
> >> >> >> > return false;
> >> >> >> > }
> >> >> >> > }
>
> >> >> >> --
> >> >> >> Romain Guy
> >> >> >> Android framework engineer
> >> >> >> romain...@android.com
>
> >> >> >> Note: please don't send private questions to me, as I don't have time
> >> >> >> to provide private support. All such questions should be posted on
> >> >> >> public forums, where I and others can see and answer them
>
> >> >> --
> >> >> Romain Guy
> >> >> Android framework engineer
> >> >> romain...@android.com
>
> >> >> Note: please don't send private questions to me, as I don't have time
> >> >> to provide private support. All such questions should be posted on
> >> >> public forums, where I and others can see and answer them
>
> >> --
> >> Romain Guy
> >> Android framework engineer
> >> romain...@android.com
>
> >> Note: please don't send private questions to me, as I don't have time
> >> to provide private support. All such questions should be posted on
> >> public forums, where I and others can see and answer them
>
> --
> Romain Guy
> Android framework engineer
> romain...@android.com
>
> Note: please don't send private questions to me, as I don't have time
> to provide private support. All such questions should be posted on
> public forums, where I and others can see and answer them
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