Fix segfault at plasma_applet_animation_example from kdeexample

Patch-by: Andre L. V. Loureiro <loureiro.andrew@gmail.com>

svn path=/branches/KDE/4.4/kdelibs/; revision=1082153

animations/rotationstacked.cpp

@@ -32,12 +32,12 @@ RotationStackedAnimation::RotationStackedAnimation(QObject *parent)
 {
     m_backRotation = new QGraphicsRotation(this);
     m_frontRotation = new QGraphicsRotation(this);
-    m_sLayout = new StackedLayout;
+    m_wLayout = new StackedLayout;
 }
 
 RotationStackedAnimation::~RotationStackedAnimation()
 {
-    delete m_sLayout;
+    delete m_wLayout.data();
 }
 
 void RotationStackedAnimation::setMovementDirection(const qint8 &direction)
@@ -69,15 +69,17 @@ void RotationStackedAnimation::setBackWidget(QGraphicsWidget *backWidget)
 {
     m_backWidget = backWidget;
 
-    if(targetWidget()) {
-        m_sLayout->addWidget(targetWidget());
-        m_sLayout->addWidget(m_backWidget.data());
+    StackedLayout *layout = m_wLayout.data();
+
+    if(targetWidget() && backWidget && layout) {
+        layout->addWidget(targetWidget());
+        layout->addWidget(backWidget);
     }
 }
 
 QGraphicsLayoutItem *RotationStackedAnimation::layout()
 {
-    return m_sLayout;
+    return m_wLayout.data();
 }
 
 void RotationStackedAnimation::updateState(
@@ -141,19 +143,24 @@ void RotationStackedAnimation::updateState(
 
 void RotationStackedAnimation::updateCurrentTime(int currentTime)
 {
-QGraphicsWidget *w = targetWidget();
-if(w) {
-    qreal delta;
-    if (currentTime <= duration()/2) {
-        delta = Animation::easingCurve().valueForProgress(
-                (currentTime * 2) / qreal(duration()));
-        m_sLayout->setCurrentWidgetIndex(0);
-        delta = m_frontEndAngle * delta;
+    StackedLayout *layout = m_wLayout.data();
+    if (!layout) {
+        return;
+    }
+
+    QGraphicsWidget *w = targetWidget();
+    if (w) {
+        qreal delta;
+        if (currentTime <= duration()/2) {
+            delta = Animation::easingCurve().valueForProgress(
+                    (currentTime * 2) / qreal(duration()));
+            layout->setCurrentWidgetIndex(0);
+            delta = m_frontEndAngle * delta;
             m_frontRotation->setAngle(delta);
         } else {
             delta = Animation::easingCurve().valueForProgress(
                     (currentTime/2) / qreal(duration()));
-            m_sLayout->setCurrentWidgetIndex(1);
+            layout->setCurrentWidgetIndex(1);
             delta = m_backEndAngle * delta;
             m_backRotation->setAngle(delta);
         }

animations/rotationstacked_p.h

@@ -115,13 +115,12 @@ private:
     int m_backEndAngle;
     /**  Object the animation(s) should act upon. */
     QWeakPointer<QGraphicsWidget> m_backWidget;
+    /** Layout where widget would be added */
+    QWeakPointer<StackedLayout> m_wLayout;
     /** Back Widget Rotation transform object */
     QGraphicsRotation *m_backRotation;
     /** Front Widget Rotation transform object */
     QGraphicsRotation *m_frontRotation;
-    /** rotation stacked layout where the widget would be added */
-    StackedLayout *m_sLayout;
-
 };
 } // Plasma
 

animations/stackedlayout.cpp

@@ -21,7 +21,7 @@
 #include <QDebug>
 
 StackedLayout::StackedLayout(QGraphicsLayoutItem *parent)
-    : QGraphicsLayout(parent), m_currentWidgetIndex(-1)
+    : QObject(0), m_currentWidgetIndex(-1), QGraphicsLayout(parent)
 {
 }
 

animations/stackedlayout.h

@@ -20,8 +20,11 @@
 
 #include <QGraphicsLayout>
 #include <QList>
+#include <QObject>
 
-class StackedLayout : public QGraphicsLayout {
+class StackedLayout : public QObject, public QGraphicsLayout
+{
+Q_OBJECT
     public:
         explicit StackedLayout(QGraphicsLayoutItem *parent = 0);
         ~StackedLayout();