Abstract expression and binding APIs

By splitting the interface through which the system interacts with bindings
away from a specific implementation, we can introduce highly specialized
implementations for specific optimizations.

This commit also includes a sample optimization for object properties being
assigned directly from a local id.

1 files changed, 91 insertions, 0 deletions

diff --git a/src/declarative/qml/qmlbindingoptimizations_p.h b/src/declarative/qml/qmlbindingoptimizations_p.h
new file mode 100644
index 0000000..f50972d
--- /dev/null
+++ b/src/declarative/qml/qmlbindingoptimizations_p.h
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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (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 either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QMLBINDINGOPTIMIZATIONS_P_H
+#define QMLBINDINGOPTIMIZATIONS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qmlexpression_p.h>
+#include <QtDeclarative/qmlbinding.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+class QmlBindingIdOptimization : public QmlAbstractExpression, 
+                                 public QmlAbstractBinding
+{
+public:
+    QmlBindingIdOptimization(QObject *object, int propertyIdx,
+                             QmlContext *context, int id);
+
+    // Inherited from QmlAbstractBinding
+    virtual void setEnabled(bool);
+    virtual int propertyIndex();
+    virtual void update();
+
+    void reset();
+
+private:
+    QmlBindingIdOptimization **m_prev;
+    QmlBindingIdOptimization  *m_next;
+
+    QObject *m_object;
+    int m_propertyIdx;
+    int m_id;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QMLBINDINGOPTIMIZATIONS_P_H
+