add virtual QQuickPointerHandler::onGrabChanged and signal grabChanged

Some handlers will need to react to gaining or losing a grab, in both
C++ and QML.

Change-Id: I25b94800e3eaeabb0782315c679813ec735d4d51
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/quick/handlers/qquickpointerhandler_p.h b/src/quick/handlers/qquickpointerhandler_p.h
index 95900c50f0..9595897d72 100644
--- a/src/quick/handlers/qquickpointerhandler_p.h
+++ b/src/quick/handlers/qquickpointerhandler_p.h
@@ -89,6 +89,7 @@ Q_SIGNALS:
     void enabledChanged();
     void activeChanged();
     void targetChanged();
+    void grabChanged(QQuickEventPoint *point);
     void canceled(QQuickEventPoint *point);
 
 protected:
@@ -97,6 +98,7 @@ protected:
     virtual void handlePointerEventImpl(QQuickPointerEvent *event);
     void setActive(bool active);
     virtual void onActiveChanged() { }
+    virtual void onGrabChanged(QQuickEventPoint *) { }
     void setGrab(QQuickEventPoint *point, bool grab);
     virtual void handleGrabCancel(QQuickEventPoint *point);
     QPointF eventPos(const QQuickEventPoint *point) const;