Clean up dangling pointers in the particle system

When the scenegraph has been invalidated all node
pointers have been deleted. In the image particle case
the material is managed by the nodes and must also
be reset.

Change-Id: I867f0d36a3ea281a58c21f04c937b16b042ef373
Reviewed-by: Kim M. Kalland <kim.kalland@nokia.com>
Reviewed-by: Alan Alpert <alan.alpert@nokia.com>

diff --git a/src/quick/particles/qquickcustomparticle.cpp b/src/quick/particles/qquickcustomparticle.cpp
index 3647e5b..6f10307 100644 (file)
--- a/src/quick/particles/qquickcustomparticle.cpp
+++ b/src/quick/particles/qquickcustomparticle.cpp
@@ -139,6 +139,12 @@ QQuickCustomParticle::QQuickCustomParticle(QQuickItem* parent)
 
 class QQuickShaderEffectMaterialObject : public QObject, public QQuickShaderEffectMaterial { };
 
+void QQuickCustomParticle::sceneGraphInvalidated()
+{
+    m_nodes.clear();
+    m_rootNode = 0;
+}
+
 QQuickCustomParticle::~QQuickCustomParticle()
 {
     if (m_material)

diff --git a/src/quick/particles/qquickcustomparticle_p.h b/src/quick/particles/qquickcustomparticle_p.h
index 29f3d19..e04ac70 100644 (file)
--- a/src/quick/particles/qquickcustomparticle_p.h
+++ b/src/quick/particles/qquickcustomparticle_p.h
@@ -93,6 +93,8 @@ protected:
     QQuickShaderEffectNode *buildCustomNodes();
     void performPendingResize();
 
+    void sceneGraphInvalidated();
+
 private:
     void buildData();
 

diff --git a/src/quick/particles/qquickimageparticle.cpp b/src/quick/particles/qquickimageparticle.cpp
index 386892a..d9eb6ed 100644 (file)
--- a/src/quick/particles/qquickimageparticle.cpp
+++ b/src/quick/particles/qquickimageparticle.cpp
@@ -839,6 +839,13 @@ QQmlListProperty<QQuickSprite> QQuickImageParticle::sprites()
     return QQmlListProperty<QQuickSprite>(this, &m_sprites, spriteAppend, spriteCount, spriteAt, spriteClear);
 }
 
+void QQuickImageParticle::sceneGraphInvalidated()
+{
+    m_nodes.clear();
+    m_rootNode = 0;
+    m_material = 0;
+}
+
 void QQuickImageParticle::setImage(const QUrl &image)
 {
     if (image.isEmpty()){

diff --git a/src/quick/particles/qquickimageparticle_p.h b/src/quick/particles/qquickimageparticle_p.h
index dca524b..4db2c98 100644 (file)
--- a/src/quick/particles/qquickimageparticle_p.h
+++ b/src/quick/particles/qquickimageparticle_p.h
@@ -348,6 +348,8 @@ protected:
     void prepareNextFrame();
     void buildParticleNodes();
 
+    void sceneGraphInvalidated();
+
 private slots:
     void createEngine(); //### method invoked by sprite list changing (in engine.h) - pretty nasty
 

diff --git a/src/quick/particles/qquickparticlepainter.cpp b/src/quick/particles/qquickparticlepainter.cpp
index f46f2f2..e490b70 100644 (file)
--- a/src/quick/particles/qquickparticlepainter.cpp
+++ b/src/quick/particles/qquickparticlepainter.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "qquickparticlepainter_p.h"
+#include <QQuickCanvas>
 #include <QDebug>
 QT_BEGIN_NAMESPACE
 /*!
@@ -65,10 +66,22 @@ QT_BEGIN_NAMESPACE
 */
 QQuickParticlePainter::QQuickParticlePainter(QQuickItem *parent) :
     QQuickItem(parent),
-    m_system(0), m_count(0), m_pleaseReset(true)
+    m_system(0), m_count(0), m_pleaseReset(true), m_canvas(0)
 {
 }
 
+void QQuickParticlePainter::itemChange(ItemChange change, const ItemChangeData &data)
+{
+    if (change == QQuickItem::ItemSceneChange) {
+        if (m_canvas)
+            disconnect(m_canvas, SIGNAL(sceneGraphInvalidated()), this, SLOT(sceneGraphInvalidated()));
+        m_canvas = data.canvas;
+        if (m_canvas)
+            connect(m_canvas, SIGNAL(sceneGraphInvalidated()), this, SLOT(sceneGraphInvalidated()), Qt::DirectConnection);
+
+    }
+}
+
 void QQuickParticlePainter::componentComplete()
 {
     if (!m_system && qobject_cast<QQuickParticleSystem*>(parentItem()))

diff --git a/src/quick/particles/qquickparticlepainter_p.h b/src/quick/particles/qquickparticlepainter_p.h
index ebe76d9..1ae4625 100644 (file)
--- a/src/quick/particles/qquickparticlepainter_p.h
+++ b/src/quick/particles/qquickparticlepainter_p.h
@@ -76,6 +76,8 @@ public:
         return m_groups;
     }
 
+    void itemChange(ItemChange, const ItemChangeData &);
+
 signals:
     void countChanged();
     void systemChanged(QQuickParticleSystem* arg);
@@ -96,6 +98,9 @@ public slots:
 
     void calcSystemOffset(bool resetPending = false);
 
+private slots:
+    virtual void sceneGraphInvalidated() {}
+
 protected:
     /* Reset resets all your internal data structures. But anything attached to a particle should
        be in attached data. So reset + reloads should have no visible effect.
@@ -121,6 +126,8 @@ protected:
     QStringList m_groups;
     QPointF m_systemOffset;
 
+    QQuickCanvas *m_canvas;
+
 private:
     QSet<QPair<int,int> > m_pendingCommits;
 };