private void SendFakeEvent(MotionEvent e, MotionEventActions forcedAction)
{
var fake_event = MotionEvent.ObtainNoHistory(e);
fake_event.Action = forcedAction;
ContentView.ForceHandleTouchEvent(fake_event);
fake_event.Recycle();
}
private bool HandleUpEvent(MotionEvent e)
{
last_touch_y = -1;
if (refresh_state == PullToRefresharpRefreshState.ReleaseToRefresh)
{
UpdateRefreshState(PullToRefresharpRefreshState.Refreshing);
}
if (current_scroll_y < 0)
{
Post(StartSnapback);
ContentView.IgnoreTouchEvents = false;
}
if (did_steal_event_stream && current_scroll_y >= 0)
{
did_steal_event_stream = false;
ContentView.ForceHandleTouchEvent(e);
}
if (should_cancel_before_up)
{
// This means we revealed the ptr header and should cancel the event
// so the content view doesn't register a click on up.
should_cancel_before_up = false;
SendFakeEvent(e, MotionEventActions.Cancel);
}
else if (should_send_down_before_up)
{
should_send_down_before_up = false;
SendFakeEvent(e, MotionEventActions.Down);
}
return(false);
}
public override bool OnTouchEvent(MotionEvent e)
{
if (!IsPullEnabled)
{
return(base.OnTouchEvent(e));
}
if (null == ContentView)
{
return(base.OnTouchEvent(e));
}
if (ContentView is AbsListView && ((AbsListView)ContentView).FastScrollEnabled)
{
// An adimittedly crude way to determine if touch is in fast scroll, but
// should accomplish the goal of not displaying ptr header.
// This is crude because there is not a definitive way to determine
// a) if the fast scroller is visible or
// b) the width of the scroller
if (Resources.DisplayMetrics.WidthPixels - e.RawX < fastscroll_thumb_width)
{
return(false); // let the list view handle this
}
}
switch (e.ActionMasked)
{
case MotionEventActions.Down:
last_touch_y = ContentView.IsAtTop ? (int)e.RawY : -1;
if (!ContentView.IsAtTop)
{
send_down_event = false; // because this event will reach the ContentView
}
else
{
should_send_down_before_up = true;
}
return(ContentView.IsAtTop);
case MotionEventActions.Move:
if (did_steal_event_stream && current_scroll_y >= 0)
{
if (send_down_event)
{
did_steal_event_stream = false;
send_down_event = false;
ContentView.IgnoreTouchEvents = false;
SendFakeEvent(e, MotionEventActions.Down);
}
return(true);
}
if (last_touch_y == -1)
{
last_touch_y = (int)e.RawY;
return(true);
}
var y_delta = last_touch_y - (int)e.RawY;
last_touch_y = (int)e.RawY;
bool isMovingUp = y_delta > 0;
if (isMovingUp && current_scroll_y >= 0 || !ContentView.IsAtTop)
{
should_send_down_before_up = false;
ContentView.ForceHandleTouchEvent(e);
return(true);
}
if (ContentView.IsAtTop)
{
var new_scroll_to = isMovingUp ? (int)y_delta : (int)(y_delta * PullDownTensionFactor);
// see if this will fully hide the header
if (current_scroll_y < 0 && current_scroll_y + new_scroll_to > 0)
{
// only scroll enough to hide the header
new_scroll_to = -current_scroll_y;
}
current_scroll_y += new_scroll_to;
Header.OffsetTopAndBottom(-new_scroll_to);
((View)ContentView).OffsetTopAndBottom(-new_scroll_to);
ViewCompat.PostInvalidateOnAnimation(this);
if (current_scroll_y == 0)
{
ContentView.IgnoreTouchEvents = false;
return(true);
}
else
{
should_cancel_before_up = true;
should_send_down_before_up = false;
}
if (Math.Abs(current_scroll_y) >= header_measured_height)
{
if (refresh_state != PullToRefresharpRefreshState.Refreshing)
{
SetPullDownIconProgress(1);
UpdateRefreshState(PullToRefresharpRefreshState.ReleaseToRefresh);
}
}
else
{
// Don't update anything if we are refreshing.
if (refresh_state != PullToRefresharpRefreshState.Refreshing)
{
SetPullDownIconProgress((float)Math.Abs(current_scroll_y) / (float)header_measured_height);
UpdateRefreshState(PullToRefresharpRefreshState.PullToRefresh);
}
}
return(true);
}
return(false);
case MotionEventActions.Up:
return(HandleUpEvent(e));
}
return(base.OnTouchEvent(e));
}
