public void OnUpOrCancelMotionEvent(ObservableScrollState scrollState)
{
if (_observableScrollViewCallbacks != null)
{
_observableScrollViewCallbacks.OnUpOrCancelMotionEvent(scrollState);
}
}
public override bool OnTouchEvent(MotionEvent ev)
{
if (_mCallbacks != null)
{
switch (ev.ActionMasked)
{
case MotionEventActions.Up:
case MotionEventActions.Cancel:
_mIntercepted = false;
_mDragging = false;
_mCallbacks.OnUpOrCancelMotionEvent(_mScrollState);
break;
case MotionEventActions.Move:
if (_mPrevMoveEvent == null)
{
_mPrevMoveEvent = ev;
}
float diffY = ev.GetY() - _mPrevMoveEvent.GetY();
_mPrevMoveEvent = MotionEvent.ObtainNoHistory(ev);
if (GetCurrentScrollY() - diffY <= 0)
{
// Can't scroll anymore.
if (_mIntercepted)
{
// Already dispatched ACTION_DOWN event to parents, so stop here.
return(false);
}
// Apps can set the interception target other than the direct parent.
ViewGroup parent;
if (_mTouchInterceptionViewGroup == null)
{
parent = (ViewGroup)Parent;
}
else
{
parent = _mTouchInterceptionViewGroup;
}
// Get offset to parents. If the parent is not the direct parent,
// we should aggregate offsets from all of the parents.
float offsetX = 0;
float offsetY = 0;
for (View v = this; v != null && v != parent; v = (View)v.Parent)
{
offsetX += v.Left - v.ScrollX;
offsetY += v.Top - v.ScrollY;
}
MotionEvent eventHistoryLess = MotionEvent.ObtainNoHistory(ev);
eventHistoryLess.OffsetLocation(offsetX, offsetY);
if (parent.OnInterceptTouchEvent(eventHistoryLess))
{
_mIntercepted = true;
// If the parent wants to intercept ACTION_MOVE events,
// we pass ACTION_DOWN event to the parent
// as if these touch events just have began now.
eventHistoryLess.Action = MotionEventActions.Down;
// Return this onTouchEvent() first and set ACTION_DOWN event for parent
// to the queue, to keep events sequence.
Post(() => parent.DispatchTouchEvent(eventHistoryLess));
return(false);
}
// Even when this can't be scrolled anymore,
// simply returning false here may cause subView's click,
// so delegate it to super.
return(base.OnTouchEvent(ev));
}
break;
}
}
return(base.OnTouchEvent(ev));
}