Client: Refactor touch handling and fix various bugs

Rename mTouchPoints to mPendingTouchPoints, to clarify that they're the
accumulated state so far, which will be applied with the wl_touch.frame
event. QWaylandInputDevice::Touch::mPrevTouchPoints is no longer needed
and has been removed.

Fixes the following issues with the old approach:

- touchPointsReleased() only checked mTouchPoints, which was cleared on
touch_frame and populated again on touch_motion and touch_down, which
meant that it could return true even though there were still touch
points left. Leading to the workaround for missing wl_touch.frame events
on Weston being triggered to often.
- Touch focus was cleared on any wl_touch.up event, not just the last
one.
- The order of the touch events was not stable and relied on the order
of the events (QTBUG-77014).

Fixes: QTBUG-77014
Change-Id: Ic3ecdc87e77b0e0276afefd127ad2b965142cbd4
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 1 insertions, 2 deletions

diff --git a/src/client/qwaylandinputdevice_p.h b/src/client/qwaylandinputdevice_p.h
index 7aa86539b..d9bae9836 100644
--- a/src/client/qwaylandinputdevice_p.h
+++ b/src/client/qwaylandinputdevice_p.h
@@ -304,8 +304,7 @@ public:
 
     QWaylandInputDevice *mParent = nullptr;
     QPointer<QWaylandWindow> mFocus;
-    QList<QWindowSystemInterface::TouchPoint> mTouchPoints;
-    QList<QWindowSystemInterface::TouchPoint> mPrevTouchPoints;
+    QList<QWindowSystemInterface::TouchPoint> mPendingTouchPoints;
 };
 
 class QWaylandPointerEvent