Make bindings refcounted

Refcounting our bindings greatly simplifies our memory management
of the objects and ensures we safely clean them all up. In addition,
it allows us to remove the m_mePtr and weak reference handling from
QQmlAbstractBinding as we can safely handle this through the same
mechanism.

Change-Id: If23ebc8be276096146952b0008b62018f5d57faf
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

5 files changed, 25 insertions, 34 deletions

diff --git a/src/quick/util/qquickpropertychanges.cpp b/src/quick/util/qquickpropertychanges.cpp
index 707323f2e2..bb8b5250a0 100644
--- a/src/quick/util/qquickpropertychanges.cpp
+++ b/src/quick/util/qquickpropertychanges.cpp
@@ -464,10 +464,10 @@ QQuickPropertyChanges::ActionList QQuickPropertyChanges::actions()
                 // XXX TODO: add a static QQmlJavaScriptExpression::evaluate(QString)
                 // so that we can avoid creating then destroying the binding in this case.
                 a.toValue = newBinding->evaluate();
-                newBinding->destroy();
+                delete newBinding;
             } else {
                 newBinding->setTarget(prop);
-                a.toBinding = QQmlAbstractBinding::getPointer(newBinding);
+                a.toBinding = newBinding;
                 a.deletableToBinding = true;
             }
 
@@ -558,7 +558,7 @@ void QQuickPropertyChanges::changeValue(const QString &name, const QVariant &val
         if (entry.name == name) {
             expressionIterator.remove();
             if (state() && state()->isStateActive()) {
-                QQmlPropertyPrivate::removeBinding(d->property(name), QQmlPropertyPrivate::DestroyOldBinding);
+                QQmlPropertyPrivate::removeBinding(d->property(name));
                 d->property(name).write(value);
             }
 
@@ -656,10 +656,10 @@ void QQuickPropertyChanges::changeExpression(const QString &name, const QString
                 // XXX TODO: add a static QQmlJavaScriptExpression::evaluate(QString)
                 // so that we can avoid creating then destroying the binding in this case.
                 action.toValue = newBinding->evaluate();
-                newBinding->destroy();
+                delete newBinding;
             } else {
                 newBinding->setTarget(action.property);
-                action.toBinding = QQmlAbstractBinding::getPointer(newBinding);
+                action.toBinding = newBinding;
                 action.deletableToBinding = true;
 
                 state()->addEntryToRevertList(action);
diff --git a/src/quick/util/qquickstate.cpp b/src/quick/util/qquickstate.cpp
index 6c57bdc171..c018399396 100644
--- a/src/quick/util/qquickstate.cpp
+++ b/src/quick/util/qquickstate.cpp
@@ -157,11 +157,6 @@ QQuickState::~QQuickState()
     Q_D(QQuickState);
     if (d->group)
         d->group->removeState(this);
-
-    foreach (const QQuickSimpleAction &action, d->revertList) {
-        if (action.binding())
-            action.binding()->destroy();
-    }
 }
 
 /*!
@@ -362,7 +357,6 @@ void QQuickStateAction::deleteFromBinding()
 {
     if (fromBinding) {
         QQmlPropertyPrivate::removeBinding(property);
-        fromBinding->destroy();
         fromBinding = 0;
     }
 }
@@ -413,9 +407,6 @@ bool QQuickState::changeBindingInRevertList(QObject *target, const QString &name
         while (revertListIterator.hasNext()) {
             QQuickSimpleAction &simpleAction = revertListIterator.next();
             if (simpleAction.specifiedObject() == target && simpleAction.specifiedProperty() == name) {
-                if (simpleAction.binding())
-                    simpleAction.binding()->destroy();
-
                 simpleAction.setBinding(binding);
                 return true;
             }
@@ -435,7 +426,7 @@ bool QQuickState::removeEntryFromRevertList(QObject *target, const QString &name
         while (revertListIterator.hasNext()) {
             QQuickSimpleAction &simpleAction = revertListIterator.next();
             if (simpleAction.property().object() == target && simpleAction.property().name() == name) {
-                QQmlPropertyPrivate::removeBinding(simpleAction.property(), QQmlPropertyPrivate::DestroyOldBinding);
+                QQmlPropertyPrivate::removeBinding(simpleAction.property());
 
                 simpleAction.property().write(simpleAction.value());
                 if (simpleAction.binding())
@@ -469,7 +460,7 @@ void QQuickState::removeAllEntriesFromRevertList(QObject *target)
          while (revertListIterator.hasNext()) {
              QQuickSimpleAction &simpleAction = revertListIterator.next();
              if (simpleAction.property().object() == target) {
-                 QQmlPropertyPrivate::removeBinding(simpleAction.property(), QQmlPropertyPrivate::DestroyOldBinding);
+                 QQmlPropertyPrivate::removeBinding(simpleAction.property());
 
                  simpleAction.property().write(simpleAction.value());
                  if (simpleAction.binding())
@@ -493,7 +484,7 @@ void QQuickState::addEntriesToRevertList(const QList<QQuickStateAction> &actionL
             const QQuickStateAction &action = actionListIterator.next();
             QQuickSimpleAction simpleAction(action);
             action.property.write(action.toValue);
-            if (!action.toBinding.isNull())
+            if (action.toBinding)
                 QQmlPropertyPrivate::setBinding(action.toBinding.data());
 
             simpleActionList.append(simpleAction);
@@ -608,7 +599,7 @@ void QQuickState::apply(QQuickTransition *trans, QQuickState *revert)
             for (int jj = 0; jj < d->revertList.count(); ++jj) {
                 if (d->revertList.at(jj).property() == action.property) {
                     found = true;
-                    if (d->revertList.at(jj).binding() != action.fromBinding) {
+                    if (d->revertList.at(jj).binding() != action.fromBinding.data()) {
                         action.deleteFromBinding();
                     }
                     break;
@@ -652,13 +643,13 @@ void QQuickState::apply(QQuickTransition *trans, QQuickState *revert)
         }
         if (!found) {
             QVariant cur = d->revertList.at(ii).property().read();
-            QQmlPropertyPrivate::removeBinding(d->revertList.at(ii).property(), QQmlPropertyPrivate::DestroyOldBinding);
+            QQmlPropertyPrivate::removeBinding(d->revertList.at(ii).property());
 
             QQuickStateAction a;
             a.property = d->revertList.at(ii).property();
             a.fromValue = cur;
             a.toValue = d->revertList.at(ii).value();
-            a.toBinding = QQmlAbstractBinding::getPointer(d->revertList.at(ii).binding());
+            a.toBinding = d->revertList.at(ii).binding();
             a.specifiedObject = d->revertList.at(ii).specifiedObject();
             a.specifiedProperty = d->revertList.at(ii).specifiedProperty();
             a.event = d->revertList.at(ii).event();
diff --git a/src/quick/util/qquickstate_p.h b/src/quick/util/qquickstate_p.h
index 0c774635d8..26069caa34 100644
--- a/src/quick/util/qquickstate_p.h
+++ b/src/quick/util/qquickstate_p.h
@@ -39,13 +39,14 @@
 #include <QtCore/qobject.h>
 #include <QtCore/qsharedpointer.h>
 #include <private/qtquickglobal_p.h>
+#include <private/qqmlabstractbinding_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class QQuickStateActionEvent;
-class QQmlAbstractBinding;
 class QQmlBinding;
 class QQmlExpression;
+
 class QQuickStateAction
 {
 public:
@@ -63,8 +64,8 @@ public:
     QVariant fromValue;
     QVariant toValue;
 
-    QQmlAbstractBinding *fromBinding;
-    QWeakPointer<QQmlAbstractBinding> toBinding;
+    QQmlAbstractBinding::Ptr fromBinding;
+    QQmlAbstractBinding::Ptr toBinding;
     QQuickStateActionEvent *event;
 
     //strictly for matching
diff --git a/src/quick/util/qquickstate_p_p.h b/src/quick/util/qquickstate_p_p.h
index fc589f0d2d..e6ecb424e5 100644
--- a/src/quick/util/qquickstate_p_p.h
+++ b/src/quick/util/qquickstate_p_p.h
@@ -71,7 +71,7 @@ public:
         if (state == StartState) {
             m_value = a.fromValue;
             if (QQmlPropertyPrivate::binding(m_property)) {
-                m_binding = QQmlAbstractBinding::getPointer(QQmlPropertyPrivate::binding(m_property));
+                m_binding = QQmlPropertyPrivate::binding(m_property);
             }
             m_reverseEvent = true;
         } else {
@@ -88,7 +88,7 @@ public:
     QQuickSimpleAction(const QQuickSimpleAction &other)
         :  m_property(other.m_property),
         m_value(other.m_value),
-        m_binding(QQmlAbstractBinding::getPointer(other.binding())),
+        m_binding(other.binding()),
         m_specifiedObject(other.m_specifiedObject),
         m_specifiedProperty(other.m_specifiedProperty),
         m_event(other.m_event),
@@ -100,7 +100,7 @@ public:
     {
         m_property = other.m_property;
         m_value = other.m_value;
-        m_binding = QQmlAbstractBinding::getPointer(other.binding());
+        m_binding = other.binding();
         m_specifiedObject = other.m_specifiedObject;
         m_specifiedProperty = other.m_specifiedProperty;
         m_event = other.m_event;
@@ -131,7 +131,7 @@ public:
 
     void setBinding(QQmlAbstractBinding *binding)
     {
-        m_binding = QQmlAbstractBinding::getPointer(binding);
+        m_binding = binding;
     }
 
     QQmlAbstractBinding *binding() const
@@ -162,7 +162,7 @@ public:
 private:
     QQmlProperty m_property;
     QVariant m_value;
-    QQmlAbstractBinding::Pointer m_binding;
+    QQmlAbstractBinding::Ptr m_binding;
     QObject *m_specifiedObject;
     QString m_specifiedProperty;
     QQuickStateActionEvent *m_event;
diff --git a/src/quick/util/qquicktransitionmanager.cpp b/src/quick/util/qquicktransitionmanager.cpp
index ac57ac20a4..14480ac1bf 100644
--- a/src/quick/util/qquicktransitionmanager.cpp
+++ b/src/quick/util/qquicktransitionmanager.cpp
@@ -101,7 +101,7 @@ void QQuickTransitionManager::complete()
 void QQuickTransitionManagerPrivate::applyBindings()
 {
     foreach(const QQuickStateAction &action, bindingsList) {
-        if (!action.toBinding.isNull()) {
+        if (action.toBinding) {
             QQmlPropertyPrivate::setBinding(action.toBinding.data());
         } else if (action.event) {
             if (action.reverseEvent)
@@ -155,7 +155,7 @@ void QQuickTransitionManager::transition(const QList<QQuickStateAction> &list,
         // Apply all the property and binding changes
         for (int ii = 0; ii < applyList.size(); ++ii) {
             const QQuickStateAction &action = applyList.at(ii);
-            if (!action.toBinding.isNull()) {
+            if (action.toBinding) {
                 QQmlPropertyPrivate::setBinding(action.toBinding.data(), QQmlPropertyPrivate::None, QQmlPropertyPrivate::BypassInterceptor | QQmlPropertyPrivate::DontRemoveBinding);
             } else if (!action.event) {
                 QQmlPropertyPrivate::write(action.property, action.toValue, QQmlPropertyPrivate::BypassInterceptor | QQmlPropertyPrivate::DontRemoveBinding);
@@ -175,7 +175,7 @@ void QQuickTransitionManager::transition(const QList<QQuickStateAction> &list,
                 continue;
             }
             const QQmlProperty &prop = action->property;
-            if (!action->toBinding.isNull() || !action->toValue.isValid()) {
+            if (action->toBinding || !action->toValue.isValid()) {
                 action->toValue = prop.read();
             }
         }
@@ -269,10 +269,9 @@ void QQuickTransitionManager::cancel()
 
     for(int i = 0; i < d->bindingsList.count(); ++i) {
         QQuickStateAction action = d->bindingsList[i];
-        if (!action.toBinding.isNull() && action.deletableToBinding) {
+        if (action.toBinding && action.deletableToBinding) {
             QQmlPropertyPrivate::removeBinding(action.property);
-            action.toBinding.data()->destroy();
-            action.toBinding.clear();
+            action.toBinding = 0;
             action.deletableToBinding = false;
         } else if (action.event) {
             //### what do we do here?