add QQuickPointerHandler::handleGrabCancel; call in setGrab

Only one handler can be the grabber at one time, so we need to ensure
that we notify the others when they lose the grab. Also handle this
in QQuickPointerSingleHandler: forget m_currentPointId, so that
wantsPointerEvent will not continue to "want" the same ID.
Also add the canceled(QQuickEventPoint *point) signal, which
is one of the four possible "state signals" (press, update, release,
cancel) but which we didn't commit to adding yet.

Change-Id: I46256acb75ece863d84e812af2d30cb0b12e3c1f
Reviewed-by: Jan Arve Sæther <jan-arve.saether@theqtcompany.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/quick/handlers/qquickpointerhandler_p.h b/src/quick/handlers/qquickpointerhandler_p.h
index d7ac713638..42d9489f84 100644
--- a/src/quick/handlers/qquickpointerhandler_p.h
+++ b/src/quick/handlers/qquickpointerhandler_p.h
@@ -86,6 +86,7 @@ Q_SIGNALS:
     void enabledChanged();
     void activeChanged();
     void targetChanged();
+    void canceled(QQuickEventPoint *point);
 
 protected:
     QQuickPointerEvent *currentEvent() { return m_currentEvent; }
@@ -93,6 +94,7 @@ protected:
     virtual void setActive(bool active);
     virtual void handlePointerEventImpl(QQuickPointerEvent *event);
     void setGrab(QQuickEventPoint *point, bool grab);
+    virtual void handleGrabCancel(QQuickEventPoint *point);
     QPointF eventPos(const QQuickEventPoint *point) const;
     bool targetContains(const QQuickEventPoint *point) const;
 
@@ -101,6 +103,8 @@ private:
     QQuickItem *m_target;
     bool m_enabled : 1;
     bool m_active : 1;
+
+    friend class QQuickEventPoint;
 };
 
 QT_END_NAMESPACE