Add a declarative data ptr to QObjectPrivate

This data ptr does not increase the size of the QObject, as we take advantage of space only used during destruction.  Currently this data is only used to store an object's QmlContext, but it will be used for more later.

2 files changed, 19 insertions, 1 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 638c7d1..220e132 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -842,6 +842,14 @@ QObject::~QObject()
 
     d->eventFilters.clear();
 
+    // As declarativeData is in a union with currentChildBeingDeleted, this must
+    // be done (and declarativeData set back to 0) before deleting children.
+    if(d->declarativeData) {
+        QDeclarativeData *dd = d->declarativeData;
+        d->declarativeData = 0;
+        dd->destroyed(this);
+    }
+
     if (!d->children.isEmpty())
         d->deleteChildren();
 
diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 31b1593..81d3aba 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -85,6 +85,13 @@ inline QObjectData::~QObjectData() {}
 
 enum { QObjectPrivateVersion = QT_VERSION };
 
+class Q_CORE_EXPORT QDeclarativeData 
+{
+public:
+    virtual ~QDeclarativeData() {}
+    virtual void destroyed(QObject *) {}
+};
+
 class Q_CORE_EXPORT QObjectPrivate : public QObjectData
 {
     Q_DECLARE_PUBLIC(QObject)
@@ -118,7 +125,10 @@ public:
     // object currently activating the object
     Sender *currentSender;
 
-    QObject *currentChildBeingDeleted;
+    union {
+        QObject *currentChildBeingDeleted;
+        QDeclarativeData *declarativeData;
+    };
 
     bool isSender(const QObject *receiver, const char *signal) const;
     QObjectList receiverList(const char *signal) const;