Positioners now watch for sibling order changes

Task-number: QT-2241

3 files changed, 75 insertions, 9 deletions

diff --git a/src/declarative/graphicsitems/qmlgraphicsitem_p.h b/src/declarative/graphicsitems/qmlgraphicsitem_p.h
index f98c121..e1d7342 100644
--- a/src/declarative/graphicsitems/qmlgraphicsitem_p.h
+++ b/src/declarative/graphicsitems/qmlgraphicsitem_p.h
@@ -232,6 +232,24 @@ public:
         emit q_func()->wantsFocusChanged();
     }
 
+    // Reimplemented from QGraphicsItemPrivate
+    virtual void siblingOrderChange()
+    {
+        foreach(QmlGraphicsItemPrivate* other, siblingOrderNotifiees)
+            other->otherSiblingOrderChange(this);
+    }
+    QList<QmlGraphicsItemPrivate*> siblingOrderNotifiees;
+    void registerSiblingOrderNotification(QmlGraphicsItemPrivate* other)
+    {
+        siblingOrderNotifiees << other;
+    }
+    void unregisterSiblingOrderNotification(QmlGraphicsItemPrivate* other)
+    {
+        siblingOrderNotifiees.removeAll(other);
+    }
+    virtual void otherSiblingOrderChange(QmlGraphicsItemPrivate* other) {Q_UNUSED(other)}
+
+
     static int consistentTime;
     static QTime currentTime();
     static void Q_DECLARATIVE_EXPORT setConsistentTime(int t);
diff --git a/src/declarative/graphicsitems/qmlgraphicspositioners.cpp b/src/declarative/graphicsitems/qmlgraphicspositioners.cpp
index 3b975ba..82ccde0 100644
--- a/src/declarative/graphicsitems/qmlgraphicspositioners.cpp
+++ b/src/declarative/graphicsitems/qmlgraphicspositioners.cpp
@@ -52,6 +52,36 @@
 
 QT_BEGIN_NAMESPACE
 
+void QmlGraphicsBasePositionerPrivate::watchChanges(QmlGraphicsItem *other)
+{
+    Q_Q(QmlGraphicsBasePositioner);
+    QObject::connect(other, SIGNAL(visibleChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::connect(other, SIGNAL(opacityChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::connect(other, SIGNAL(heightChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::connect(other, SIGNAL(widthChanged()),
+                     q, SLOT(prePositioning()));
+    static_cast<QmlGraphicsItemPrivate*>(QGraphicsItemPrivate::get(other))->registerSiblingOrderNotification(this);
+    watched << other;
+}
+
+void QmlGraphicsBasePositionerPrivate::unwatchChanges(QmlGraphicsItem* other)
+{
+    Q_Q(QmlGraphicsBasePositioner);
+    QObject::disconnect(other, SIGNAL(visibleChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::disconnect(other, SIGNAL(opacityChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::disconnect(other, SIGNAL(heightChanged()),
+                     q, SLOT(prePositioning()));
+    QObject::disconnect(other, SIGNAL(widthChanged()),
+                     q, SLOT(prePositioning()));
+    static_cast<QmlGraphicsItemPrivate*>(QGraphicsItemPrivate::get(other))->unregisterSiblingOrderNotification(this);
+    watched.removeAll(other);
+}
+
 /*!
     \internal
     \class QmlGraphicsBasePositioner
@@ -204,6 +234,7 @@ void QmlGraphicsBasePositioner::prePositioning()
     if (!isComponentComplete() || d->_movingItem)
         return;
 
+    d->queuedPositioning = false;
     if (!d->_ep) {
         d->_ep = true;
         QCoreApplication::postEvent(this, new QEvent(QEvent::User));
@@ -220,14 +251,7 @@ void QmlGraphicsBasePositioner::prePositioning()
         if (!child)
             continue;
         if (!d->_items.contains(child)){
-            QObject::connect(child, SIGNAL(visibleChanged()),
-                             this, SLOT(prePositioning()));
-            QObject::connect(child, SIGNAL(opacityChanged()),
-                             this, SLOT(prePositioning()));
-            QObject::connect(child, SIGNAL(heightChanged()),
-                             this, SLOT(prePositioning()));
-            QObject::connect(child, SIGNAL(widthChanged()),
-                             this, SLOT(prePositioning()));
+            d->watchChanges(child);
             d->_items += child;
         }
         if (child->opacity() == 0.0){
diff --git a/src/declarative/graphicsitems/qmlgraphicspositioners_p_p.h b/src/declarative/graphicsitems/qmlgraphicspositioners_p_p.h
index 61b4497..d7a31a3 100644
--- a/src/declarative/graphicsitems/qmlgraphicspositioners_p_p.h
+++ b/src/declarative/graphicsitems/qmlgraphicspositioners_p_p.h
@@ -60,6 +60,7 @@
 #include <private/qmlstate_p.h>
 #include <private/qmltransitionmanager_p_p.h>
 #include <private/qmlstateoperations_p.h>
+#include <QtCore/QTimer>
 
 QT_BEGIN_NAMESPACE
 class QmlGraphicsBasePositionerPrivate : public QmlGraphicsItemPrivate
@@ -70,10 +71,17 @@ public:
     QmlGraphicsBasePositionerPrivate()
         : _ep(false), _componentComplete(false), _spacing(0),
         aut(QmlGraphicsBasePositioner::None), moveTransition(0), addTransition(0),
-        removeTransition(0), _movingItem(0)
+        removeTransition(0), _movingItem(0), queuedPositioning(false)
     {
     }
 
+    ~QmlGraphicsBasePositionerPrivate()
+    {
+        watched.removeAll(0);
+        foreach(QmlGraphicsItem* other, watched)
+            unwatchChanges(other);//Need to deregister from a list in QmlGI Private
+    }
+
     void init(QmlGraphicsBasePositioner::AutoUpdateType at)
     {
         aut = at;
@@ -99,6 +107,22 @@ public:
     QmlTransitionManager removeTransitionManager;
 //    QmlStateGroup *stateGroup;
     QmlGraphicsItem *_movingItem;
+
+    void watchChanges(QmlGraphicsItem *other);
+    void unwatchChanges(QmlGraphicsItem* other);
+    QList<QGuard<QmlGraphicsItem> > watched;
+    bool queuedPositioning;
+
+    virtual void otherSiblingOrderChange(QmlGraphicsItemPrivate* other)
+    {
+        Q_Q(QmlGraphicsBasePositioner);
+        Q_UNUSED(other);
+        if(!queuedPositioning){
+            //Delay is due to many children often being reordered at once
+            QTimer::singleShot(0,q,SLOT(prePositioning()));
+            queuedPositioning = true;
+        }
+    }
 };
 
 QT_END_NAMESPACE