QmlDesigner: Add Model::bindingPropertiesAboutToBeChanged

It is sometime quite useful to know the old value. For example to remove
it. We could add add the old values to the bindingPropertiesChanged but
this would be a much larger change.

Change-Id: I9b4a78602a35766c99092892b61173fc5c439978
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmldesigner/designercore/include/abstractview.h

@@ -205,6 +205,7 @@ public:
     virtual void propertiesAboutToBeRemoved(const QList<AbstractProperty>& propertyList);
     virtual void propertiesRemoved(const QList<AbstractProperty>& propertyList);
     virtual void variantPropertiesChanged(const QList<VariantProperty>& propertyList, PropertyChangeFlags propertyChange);
+    virtual void bindingPropertiesAboutToBeChanged(const QList<BindingProperty> &propertyList);
     virtual void bindingPropertiesChanged(const QList<BindingProperty>& propertyList, PropertyChangeFlags propertyChange);
     virtual void signalHandlerPropertiesChanged(const QVector<SignalHandlerProperty>& propertyList, PropertyChangeFlags propertyChange);
     virtual void rootNodeTypeChanged(const QString &type, int majorVersion, int minorVersion);

src/plugins/qmldesigner/designercore/model/abstractview.cpp

@@ -329,6 +329,8 @@ void AbstractView::variantPropertiesChanged(const QList<VariantProperty>& /*prop
 {
 }
 
+void AbstractView::bindingPropertiesAboutToBeChanged(const QList<BindingProperty> &) {}
+
 void AbstractView::bindingPropertiesChanged(const QList<BindingProperty>& /*propertyList*/, PropertyChangeFlags /*propertyChange*/)
 {
 }

src/plugins/qmldesigner/designercore/model/model.cpp

@@ -767,6 +767,21 @@ void ModelPrivate::notifyNodeIdChanged(const InternalNodePointer &node,
     });
 }
 
+void ModelPrivate::notifyBindingPropertiesAboutToBeChanged(
+    const QList<InternalBindingPropertyPointer> &internalPropertyList)
+{
+    notifyNodeInstanceViewLast([&](AbstractView *view) {
+        QList<BindingProperty> propertyList;
+        for (const InternalBindingPropertyPointer &bindingProperty : internalPropertyList) {
+            propertyList.append(BindingProperty(bindingProperty->name(),
+                                                bindingProperty->propertyOwner(),
+                                                m_model,
+                                                view));
+        }
+        view->bindingPropertiesAboutToBeChanged(propertyList);
+    });
+}
+
 void ModelPrivate::notifyBindingPropertiesChanged(
     const QList<InternalBindingPropertyPointer> &internalPropertyList,
     AbstractView::PropertyChangeFlags propertyChange)
@@ -1030,6 +1045,7 @@ void ModelPrivate::setBindingProperty(const InternalNodePointer &node, const Pro
     }
 
     InternalBindingPropertyPointer bindingProperty = node->bindingProperty(name);
+    notifyBindingPropertiesAboutToBeChanged({bindingProperty});
     bindingProperty->setExpression(expression);
     notifyBindingPropertiesChanged({bindingProperty}, propertyChange);
 }
@@ -1087,6 +1103,7 @@ void ModelPrivate::setDynamicBindingProperty(const InternalNodePointer &node,
     }
 
     InternalBindingPropertyPointer bindingProperty = node->bindingProperty(name);
+    notifyBindingPropertiesAboutToBeChanged({bindingProperty});
     bindingProperty->setDynamicExpression(dynamicPropertyType, expression);
     notifyBindingPropertiesChanged({bindingProperty}, propertyChange);
 }

src/plugins/qmldesigner/designercore/model/model_p.h

@@ -149,6 +149,8 @@ public:
 
     void notifyPropertiesRemoved(const QList<PropertyPair> &propertyList);
     void notifyPropertiesAboutToBeRemoved(const QList<InternalPropertyPointer> &internalPropertyList);
+    void notifyBindingPropertiesAboutToBeChanged(
+        const QList<InternalBindingPropertyPointer> &internalPropertyList);
     void notifyBindingPropertiesChanged(const QList<InternalBindingPropertyPointer> &internalPropertyList, AbstractView::PropertyChangeFlags propertyChange);
     void notifySignalHandlerPropertiesChanged(const QVector<InternalSignalHandlerPropertyPointer> &propertyList, AbstractView::PropertyChangeFlags propertyChange);
     void notifyVariantPropertiesChanged(const InternalNodePointer &node, const PropertyNameList &propertyNameList, AbstractView::PropertyChangeFlags propertyChange);