Add grabber context pointers

In Qt Quick we now need to keep track of which QQDeliveryAgent is
responsible when a point is grabbed, either passively or exclusively.
When we re-deliver to that grabber, we need to do it via the same agent,
so that the same scene transform is used, and the grabber will see the
event in the correct coordinate system.  It's easier to track this
mapping here instead of in a separate map in Qt Quick.

Pick-to: 6.1
Task-number: QTBUG-92944
Change-Id: I69f769c694d0da24885cdf4087e5032022bff629
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/gui/kernel/qpointingdevice_p.h b/src/gui/kernel/qpointingdevice_p.h
index 04823a3e86..d67dedf9e1 100644
--- a/src/gui/kernel/qpointingdevice_p.h
+++ b/src/gui/kernel/qpointingdevice_p.h
@@ -85,10 +85,12 @@ public:
     /*! \internal
         This struct (stored in activePoints) holds persistent state between event deliveries.
     */
+    using PassiveGrabbersMap = QFlatMap<QPointer<QObject>, QPointer<QObject>>;
     struct EventPointData {
         QEventPoint eventPoint;
         QPointer<QObject> exclusiveGrabber;
-        QList<QPointer <QObject> > passiveGrabbers;
+        QPointer<QObject> exclusiveGrabberContext;  // extra info about where the grab happened
+        PassiveGrabbersMap passiveGrabbers;         // key: passive grabber; value: context (where the grab happened)
     };
     EventPointData *queryPointById(int id) const;
     EventPointData *pointById(int id) const;