Enabling AdvancedPointerEvents for active windows causes a panic

In Symbian port of Qt, widgets that have attribute WA_AcceptTouchEvents,
are tried to set as enabled for "advanced pointer events". These are
multitouch events. However, the event enablation cannot be done after
a window has been activated.

Current implementation causes a crash in certain cases. For example,
a treewidget that is inside a inactive tab page, causes a crash when
tab page is selected.

The crash is worked around, by not allowing a active window to enable
advanced pointer events.

This fixes http://bugreports.qt.nokia.com/browse/QTBUG-12779

Task-number: QTBUG-12779
Reviewed-by: mread

3 files changed, 13 insertions, 3 deletions

diff --git a/src/gui/kernel/qapplication_s60.cpp b/src/gui/kernel/qapplication_s60.cpp
index 7c5e790..e197dc5 100644
--- a/src/gui/kernel/qapplication_s60.cpp
+++ b/src/gui/kernel/qapplication_s60.cpp
@@ -1344,6 +1344,11 @@ void QSymbianControl::setFocusSafely(bool focus)
     }
 }
 
+bool QSymbianControl::isControlActive()
+{
+    return IsActivated() ? true : false;
+}
+
 /*!
     \typedef QApplication::QS60MainApplicationFactory
     \since 4.6
diff --git a/src/gui/kernel/qt_s60_p.h b/src/gui/kernel/qt_s60_p.h
index ad6a99a..eb1aa18 100644
--- a/src/gui/kernel/qt_s60_p.h
+++ b/src/gui/kernel/qt_s60_p.h
@@ -211,6 +211,8 @@ public:
 
     void setFocusSafely(bool focus);
 
+    bool isControlActive();
+
 #ifdef Q_WS_S60
     void FadeBehindPopup(bool fade){ popupFader.FadeBehindPopup( this, this, fade); }
     void HandleStatusPaneSizeChange();
diff --git a/src/gui/kernel/qwidget_s60.cpp b/src/gui/kernel/qwidget_s60.cpp
index 7494f92..fc13c93 100644
--- a/src/gui/kernel/qwidget_s60.cpp
+++ b/src/gui/kernel/qwidget_s60.cpp
@@ -366,7 +366,7 @@ void QWidgetPrivate::create_sys(WId window, bool /* initializeWindow */, bool de
 
         // Symbian windows are always created in an inactive state
         // We perform this assignment for the case where the window is being re-created
-        // as aa result of a call to setParent_sys, on either this widget or one of its
+        // as a result of a call to setParent_sys, on either this widget or one of its
         // ancestors.
         extra->activated = 0;
 
@@ -410,7 +410,7 @@ void QWidgetPrivate::create_sys(WId window, bool /* initializeWindow */, bool de
 
         // Symbian windows are always created in an inactive state
         // We perform this assignment for the case where the window is being re-created
-        // as aa result of a call to setParent_sys, on either this widget or one of its
+        // as a result of a call to setParent_sys, on either this widget or one of its
         // ancestors.
         extra->activated = 0;
 
@@ -954,7 +954,10 @@ void QWidgetPrivate::registerTouchWindow()
     Q_Q(QWidget);
     if (q->testAttribute(Qt::WA_WState_Created) && q->windowType() != Qt::Desktop) {
         RWindow *rwindow = static_cast<RWindow *>(q->effectiveWinId()->DrawableWindow());
-        rwindow->EnableAdvancedPointers();
+        QSymbianControl *window = static_cast<QSymbianControl *>(q->effectiveWinId());
+        //Enabling advanced pointer events for controls that already have active windows causes a panic.
+        if (!window->isControlActive())
+            rwindow->EnableAdvancedPointers();
     }
 #endif
 }