src/declarative/qml/qdeclarativefastproperties.cpp
changeset 30 5dc02b23752f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/declarative/qml/qdeclarativefastproperties.cpp	Tue Jul 06 15:10:48 2010 +0300
@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "private/qdeclarativefastproperties_p.h"
+
+#include <private/qdeclarativeitem_p.h>
+
+QT_BEGIN_NAMESPACE
+
+// Adding entries to the QDeclarativeFastProperties class allows the QML 
+// binding optimizer to bypass Qt's meta system and read and, more 
+// importantly, subscribe to properties directly.  Any property that is
+// primarily read from bindings is a candidate for inclusion as a fast 
+// property.
+
+QDeclarativeFastProperties::QDeclarativeFastProperties()
+{
+    add(&QDeclarativeItem::staticMetaObject, QDeclarativeItem::staticMetaObject.indexOfProperty("parent"),
+        QDeclarativeItemPrivate::parentProperty);
+}
+
+int QDeclarativeFastProperties::accessorIndexForProperty(const QMetaObject *metaObject, int propertyIndex)
+{
+    Q_ASSERT(metaObject);
+    Q_ASSERT(propertyIndex >= 0);
+
+    // Find the "real" metaObject
+    while (metaObject->propertyOffset() > propertyIndex) 
+        metaObject = metaObject->superClass();
+
+    QHash<QPair<const QMetaObject *, int>, int>::Iterator iter = 
+        m_index.find(qMakePair(metaObject, propertyIndex));
+    if (iter != m_index.end())
+        return *iter;
+    else
+        return -1;
+}
+
+void QDeclarativeFastProperties::add(const QMetaObject *metaObject, int propertyIndex, Accessor accessor)
+{
+    Q_ASSERT(metaObject);
+    Q_ASSERT(propertyIndex >= 0);
+
+    // Find the "real" metaObject
+    while (metaObject->propertyOffset() > propertyIndex) 
+        metaObject = metaObject->superClass();
+
+    QPair<const QMetaObject *, int> data = qMakePair(metaObject, propertyIndex);
+    int accessorIndex = m_accessors.count();
+    m_accessors.append(accessor);
+    m_index.insert(data, accessorIndex);
+}
+
+QT_END_NAMESPACE