Allow parent to filter out-of-bounds synth-mouse for grabbing handler

Consider

Flickable {
	Text {
		TapHandler { gesturePolicy: TapHandler.ReleaseWithinBounds }
	}
}

On press, TapHandler gets the exclusive grab.  Now drag vertically.
The Text is short in stature, so your finger soon strays out of bounds
of the Text, likely before you have dragged past the drag threshold.
In this case, we want Flickable to continue to filter the move events
because of the fact that TapHandler is the grabber.  If it was a
MouseArea instead of a TapHandler, it already worked that way; so this
makes behavior of handlers more consistent with that.

More specifically: QQuickPointerTouchEvent::touchEventForItem() now
generates a touch event even if the touchpoint is not within the bounds
of the given item, but is grabbed by one of that item's handlers.  Until
now, we had that exception only if it was grabbed by the item itself.

tst_FlickableInterop::touchAndDragHandlerOnFlickable now always drags
the delegate at index 2 (the third one) from its upper-right corner,
upwards and to the left.  The first drag goes outside the delegate's
bounds, but the Flickable/ListView/TableView filters and takes over
anyway (on the next drag), to prove that it is correctly depending
on the grab that the TapHandler (or DragHandler) took on press.

Fixes: QTBUG-75223
Change-Id: Ie4e22c87be0af9aa3ff0146067b7705949b15c40
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 1e1674849a89db54cdbcc4e995300e3ec1624c3a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/quick/handlers/qquicktaphandler.cpp b/src/quick/handlers/qquicktaphandler.cpp
index c8525cfcb0..e71738c2d2 100644
--- a/src/quick/handlers/qquicktaphandler.cpp
+++ b/src/quick/handlers/qquicktaphandler.cpp
@@ -259,7 +259,8 @@ void QQuickTapHandler::setGesturePolicy(QQuickTapHandler::GesturePolicy gestureP
 void QQuickTapHandler::setPressed(bool press, bool cancel, QPointerEvent *event, QEventPoint &point)
 {
     if (m_pressed != press) {
-        qCDebug(lcTapHandler) << objectName() << "pressed" << m_pressed << "->" << press << (cancel ? "CANCEL" : "") << point;
+        qCDebug(lcTapHandler) << objectName() << "pressed" << m_pressed << "->" << press
+                              << (cancel ? "CANCEL" : "") << point << "gp" << m_gesturePolicy;
         m_pressed = press;
         connectPreRenderSignal(press);
         updateTimeHeld();