MouseArea: react to touch ungrab

If an event handler (such as DragHandler) takes the exclusive grab
of a touchpoint that MouseArea had already grabbed as a synth-mouse,
it should react in the same way as if its grab of the actual mouse was
stolen: release the pressed state, etc.

Fixes: QTBUG-77624
Change-Id: I51f4fb253f7d0377be421c23e617942507616e72
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
(cherry picked from commit 23df1603f514407d245a2740f32f589318ef654e)

2 files changed, 7 insertions, 0 deletions

diff --git a/src/quick/items/qquickmousearea.cpp b/src/quick/items/qquickmousearea.cpp
index 0b345697ec..5124802dbf 100644
--- a/src/quick/items/qquickmousearea.cpp
+++ b/src/quick/items/qquickmousearea.cpp
@@ -938,6 +938,12 @@ void QQuickMouseArea::mouseUngrabEvent()
     ungrabMouse();
 }
 
+void QQuickMouseArea::touchUngrabEvent()
+{
+    // allow a Pointer Handler to steal the grab from MouseArea
+    ungrabMouse();
+}
+
 bool QQuickMouseArea::sendMouseEvent(QMouseEvent *event)
 {
     Q_D(QQuickMouseArea);
diff --git a/src/quick/items/qquickmousearea_p.h b/src/quick/items/qquickmousearea_p.h
index 0a8449957f..b1a48ef2b7 100644
--- a/src/quick/items/qquickmousearea_p.h
+++ b/src/quick/items/qquickmousearea_p.h
@@ -169,6 +169,7 @@ protected:
     void mouseDoubleClickEvent(QMouseEvent *event) override;
     void mouseMoveEvent(QMouseEvent *event) override;
     void mouseUngrabEvent() override;
+    void touchUngrabEvent() override;
     void hoverEnterEvent(QHoverEvent *event) override;
     void hoverMoveEvent(QHoverEvent *event) override;
     void hoverLeaveEvent(QHoverEvent *event) override;