src/declarative/qml/qdeclarativeguard_p.h
changeset 30 5dc02b23752f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/declarative/qml/qdeclarativeguard_p.h	Tue Jul 06 15:10:48 2010 +0300
@@ -0,0 +1,157 @@
+/****************************************************************************
+**
+** 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 QtCore 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDECLARATIVEGUARD_P_H
+#define QDECLARATIVEGUARD_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of qapplication_*.cpp, qwidget*.cpp and qfiledialog.cpp.  This header
+// file may change from version to version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+#include <QtCore/qvariant.h>
+
+QT_BEGIN_NAMESPACE
+
+class QObject;
+template<class T>
+class QDeclarativeGuard
+{
+    QObject *o;
+    QDeclarativeGuard<QObject> *next;
+    QDeclarativeGuard<QObject> **prev;
+    friend class QDeclarativeData;
+public:
+    inline QDeclarativeGuard();
+    inline QDeclarativeGuard(T *);
+    inline QDeclarativeGuard(const QDeclarativeGuard<T> &);
+    inline virtual ~QDeclarativeGuard();
+
+    inline QDeclarativeGuard<T> &operator=(const QDeclarativeGuard<T> &o);
+    inline QDeclarativeGuard<T> &operator=(T *);
+    
+    inline bool isNull() const
+        { return !o; }
+
+    inline T* operator->() const
+        { return static_cast<T*>(const_cast<QObject*>(o)); }
+    inline T& operator*() const
+        { return *static_cast<T*>(const_cast<QObject*>(o)); }
+    inline operator T*() const
+        { return static_cast<T*>(const_cast<QObject*>(o)); }
+    inline T* data() const
+        { return static_cast<T*>(const_cast<QObject*>(o)); }
+
+protected:
+    virtual void objectDestroyed(T *) {}
+
+private:
+    inline void addGuard();
+    inline void remGuard();
+};
+
+QT_END_NAMESPACE
+
+Q_DECLARE_METATYPE(QDeclarativeGuard<QObject>)
+
+#include "private/qdeclarativedata_p.h"
+
+QT_BEGIN_NAMESPACE
+
+template<class T>
+QDeclarativeGuard<T>::QDeclarativeGuard()
+: o(0), next(0), prev(0)
+{
+}
+
+template<class T>
+QDeclarativeGuard<T>::QDeclarativeGuard(T *g)
+: o(g), next(0), prev(0)
+{
+    if (o) addGuard();
+}
+
+template<class T>
+QDeclarativeGuard<T>::QDeclarativeGuard(const QDeclarativeGuard<T> &g)
+: o(g.o), next(0), prev(0)
+{
+    if (o) addGuard();
+}
+
+template<class T>
+QDeclarativeGuard<T>::~QDeclarativeGuard()
+{
+    if (prev) remGuard();
+    o = 0;
+}
+
+template<class T>
+QDeclarativeGuard<T> &QDeclarativeGuard<T>::operator=(const QDeclarativeGuard<T> &g)
+{
+    if (g.o != o) {
+        if (prev) remGuard();
+        o = g.o;
+        if (o) addGuard();
+    }
+    return *this;
+}
+
+template<class T>
+QDeclarativeGuard<T> &QDeclarativeGuard<T>::operator=(T *g)
+{
+    if (g != o) {
+        if (prev) remGuard();
+        o = g;
+        if (o) addGuard();
+    }
+    return *this;
+}
+
+QT_END_NAMESPACE
+
+#endif // QDECLARATIVEGUARD_P_H