Fix pinch-zoom problem when application is deactivated

Deactivation can happen for example if some notification dialog opens
on top of the application. In this case the PinchFinished signal was not
emitted.

It is fixed so that when the QDeclarativePinchArea component receives
QEvent::WindowDeactivate event, the ongoing touch activity is cancelled,
which causes the pinch to finish. Also if QEvent::TouchUpdate event is
received without receiving QEvent::TouchBegin event first, the
QEvent::TouchUpdate event will not cause the updatePinch() method to be
called.

Task-number: ou1cimx1#948030
Change-Id: Ib8b9e1a022415be06f1a8e778b887418f32c75ef
Reviewed-by: Murray Read <ext-murray.2.read@nokia.com>
Reviewed-by: Pasi Pentikäinen <ext-pasi.a.pentikainen@nokia.com>

2 files changed, 11 insertions, 3 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativepincharea.cpp b/src/declarative/graphicsitems/qdeclarativepincharea.cpp
index 3d79f7a..bc97613 100644
--- a/src/declarative/graphicsitems/qdeclarativepincharea.cpp
+++ b/src/declarative/graphicsitems/qdeclarativepincharea.cpp
@@ -278,7 +278,10 @@ bool QDeclarativePinchArea::event(QEvent *event)
         return QDeclarativeItem::event(event);
     switch (event->type()) {
     case QEvent::TouchBegin:
-    case QEvent::TouchUpdate: {
+        d->touchEventsActive = true;
+        // No break, continue to next case.
+    case QEvent::TouchUpdate:
+        if (d->touchEventsActive) {
             QTouchEvent *touch = static_cast<QTouchEvent*>(event);
             d->touchPoints.clear();
             for (int i = 0; i < touch->touchPoints().count(); ++i) {
@@ -287,9 +290,13 @@ bool QDeclarativePinchArea::event(QEvent *event)
                 }
             }
             updatePinch();
+            return true;
         }
-        return true;
+        break;
+    case QEvent::WindowDeactivate:
+        // No break, continue to next case.
     case QEvent::TouchEnd:
+        d->touchEventsActive = false;
         d->touchPoints.clear();
         updatePinch();
         break;
diff --git a/src/declarative/graphicsitems/qdeclarativepincharea_p_p.h b/src/declarative/graphicsitems/qdeclarativepincharea_p_p.h
index b6993e9..53d0dff 100644
--- a/src/declarative/graphicsitems/qdeclarativepincharea_p_p.h
+++ b/src/declarative/graphicsitems/qdeclarativepincharea_p_p.h
@@ -71,7 +71,7 @@ public:
       , pinchRejected(false), pinchActivated(false)
       , pinch(0), pinchStartDist(0), pinchStartScale(1.0)
       , pinchLastScale(1.0), pinchStartRotation(0.0), pinchStartAngle(0.0)
-      , pinchLastAngle(0.0), pinchRotation(0.0)
+      , pinchLastAngle(0.0), pinchRotation(0.0), touchEventsActive(false)
     {
     }
 
@@ -90,6 +90,7 @@ public:
     bool inPinch : 1;
     bool pinchRejected : 1;
     bool pinchActivated : 1;
+    bool touchEventsActive : 1;
     QDeclarativePinch *pinch;
     QPointF sceneStartPoint1;
     QPointF sceneStartPoint2;