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Diffstat (limited to 'src/corelib/kernel/qguard_p.h')
-rw-r--r-- | src/corelib/kernel/qguard_p.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/corelib/kernel/qguard_p.h b/src/corelib/kernel/qguard_p.h new file mode 100644 index 000000000..6af01ac43 --- /dev/null +++ b/src/corelib/kernel/qguard_p.h @@ -0,0 +1,157 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** 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 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 http://www.qtsoftware.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QGUARD_P_H +#define QGUARD_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" + +QT_BEGIN_NAMESPACE + +class QObject; +template<class T> +class QGuard +{ + QObject *o; + QGuard<QObject> *next; + QGuard<QObject> **prev; + friend void q_guard_addGuard(QGuard<QObject> *); + friend void q_guard_removeGuard(QGuard<QObject> *); + friend class QObjectPrivate; +public: + inline QGuard(); + inline QGuard(T *); + inline QGuard(const QGuard<T> &); + inline virtual ~QGuard(); + + inline QGuard<T> &operator=(const QGuard<T> &o); + inline QGuard<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 *) {} +}; + +QT_END_NAMESPACE + +#include "private/qobject_p.h" + +QT_BEGIN_NAMESPACE + +inline void q_guard_addGuard(QGuard<QObject> *); +inline void q_guard_removeGuard(QGuard<QObject> *); + +template<class T> +QGuard<T>::QGuard() +: o(0), next(0), prev(0) +{ +} + +template<class T> +QGuard<T>::QGuard(T *g) +: o(g), next(0), prev(0) +{ + if (o) q_guard_addGuard(reinterpret_cast<QGuard<QObject> *>(this)); +} + +template<class T> +QGuard<T>::QGuard(const QGuard<T> &g) +: o(g.o), next(0), prev(0) +{ + if (o) q_guard_addGuard(reinterpret_cast<QGuard<QObject> *>(this)); +} + +template<class T> +QGuard<T>::~QGuard() +{ + if (prev) q_guard_removeGuard(reinterpret_cast<QGuard<QObject> *>(this)); + o = 0; +} + +template<class T> +QGuard<T> &QGuard<T>::operator=(const QGuard<T> &g) +{ + if (g.o != o) { + if (prev) + q_guard_removeGuard(reinterpret_cast<QGuard<QObject> *>(this)); + o = g.o; + if (o) q_guard_addGuard(reinterpret_cast<QGuard<QObject> *>(this)); + } + return *this; +} + +template<class T> +inline QGuard<T> &QGuard<T>::operator=(T *g) +{ + if (g != o) { + if (prev) + q_guard_removeGuard(reinterpret_cast<QGuard<QObject> *>(this)); + o = g; + if (o) q_guard_addGuard(reinterpret_cast<QGuard<QObject> *>(this)); + } + return *this; +} + +QT_END_NAMESPACE + +#endif // QGUARD_P_H |