Add Component.onDestruction attached property

This property complements Component.onCompleted.  It is emitted before
the destruction actually begins (for the most part) so the objects are
still alive and accessible.

The QtObject.onDestroyed signal is now blocked as it never really worked
properly anyway.

1 files changed, 28 insertions, 29 deletions

diff --git a/src/declarative/qml/qdeclarativecontext.cpp b/src/declarative/qml/qdeclarativecontext.cpp
index 42e7386..6657fea 100644
--- a/src/declarative/qml/qdeclarativecontext.cpp
+++ b/src/declarative/qml/qdeclarativecontext.cpp
@@ -42,6 +42,7 @@
 #include "qdeclarativecontext.h"
 #include "private/qdeclarativecontext_p.h"
 
+#include "private/qdeclarativecomponent_p.h"
 #include "private/qdeclarativeexpression_p.h"
 #include "private/qdeclarativeengine_p.h"
 #include "qdeclarativeengine.h"
@@ -476,21 +477,34 @@ QObject *QDeclarativeContextPrivate::context_at(QDeclarativeListProperty<QObject
 QDeclarativeContextData::QDeclarativeContextData()
 : parent(0), engine(0), isInternal(false), publicContext(0), propertyNames(0), contextObject(0),
   imports(0), childContexts(0), nextChild(0), prevChild(0), expressions(0), contextObjects(0),
-  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0)
+  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0),
+  componentAttached(0)
 {
 }
 
 QDeclarativeContextData::QDeclarativeContextData(QDeclarativeContext *ctxt)
 : parent(0), engine(0), isInternal(false), publicContext(ctxt), propertyNames(0), contextObject(0),
   imports(0), childContexts(0), nextChild(0), prevChild(0), expressions(0), contextObjects(0),
-  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0)
+  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0),
+  componentAttached(0)
 {
 }
 
-void QDeclarativeContextData::destroy()
+void QDeclarativeContextData::invalidate()
 {
-    if (linkedContext) 
-        linkedContext->destroy();
+    while (childContexts) 
+        childContexts->invalidate();
+
+    while (componentAttached) {
+        QDeclarativeComponentAttached *a = componentAttached;
+        componentAttached = a->next;
+        if (componentAttached) componentAttached->prev = &componentAttached;
+
+        a->next = 0;
+        a->prev = 0;
+
+        emit a->destruction();
+    }
 
     if (prevChild) {
         *prevChild = nextChild;
@@ -498,19 +512,17 @@ void QDeclarativeContextData::destroy()
         nextChild = 0;
         prevChild = 0;
     }
-    
-    QDeclarativeContextData *child = childContexts;
-    while (child) {
-        QDeclarativeContextData *next = child->nextChild;
 
-        child->invalidateEngines();
-        child->parent = 0;
-        child->nextChild = 0;
-        child->prevChild = 0;
+    engine = 0;
+    parent = 0;
+}
 
-        child = next;
-    }
-    childContexts = 0;
+void QDeclarativeContextData::destroy()
+{
+    if (linkedContext) 
+        linkedContext->destroy();
+
+    if (engine) invalidate();
 
     QDeclarativeAbstractExpression *expression = expressions;
     while (expression) {
@@ -573,19 +585,6 @@ void QDeclarativeContextData::setParent(QDeclarativeContextData *p)
     }
 }
 
-void QDeclarativeContextData::invalidateEngines()
-{
-    if (!engine)
-        return;
-    engine = 0;
-
-    QDeclarativeContextData *child = childContexts;
-    while (child) {
-        child->invalidateEngines();
-        child = child->nextChild;
-    }
-}
-
 /* 
 Refreshes all expressions that could possibly depend on this context.  Refreshing flushes all 
 context-tree dependent caches in the expressions, and should occur every time the context tree