diff options
Diffstat (limited to 'src/qml/qml/qqmlguard_p.h')
| -rw-r--r-- | src/qml/qml/qqmlguard_p.h | 162 |
1 files changed, 76 insertions, 86 deletions
diff --git a/src/qml/qml/qqmlguard_p.h b/src/qml/qml/qqmlguard_p.h index 3ac63926a0..685293868e 100644 --- a/src/qml/qml/qqmlguard_p.h +++ b/src/qml/qml/qqmlguard_p.h @@ -1,41 +1,5 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the QtCore module of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 2.0 or (at your option) the GNU General -** Public license version 3 or any later version approved by the KDE Free -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #ifndef QQMLGUARD_P_H #define QQMLGUARD_P_H @@ -51,87 +15,106 @@ // We mean it. // -#include <QtCore/qglobal.h> -#include <QtCore/qvariant.h> #include <private/qqmldata_p.h> +#include <private/qqmlglobal_p.h> QT_BEGIN_NAMESPACE class QQmlGuardImpl { public: + using ObjectDestroyedFn = void(*)(QQmlGuardImpl *); + inline QQmlGuardImpl(); inline QQmlGuardImpl(QObject *); inline QQmlGuardImpl(const QQmlGuardImpl &); +protected: inline ~QQmlGuardImpl(); +public: // ### make so it can be private QObject *o = nullptr; QQmlGuardImpl *next = nullptr; QQmlGuardImpl **prev = nullptr; + ObjectDestroyedFn objectDestroyed = nullptr; inline void addGuard(); inline void remGuard(); + + inline void setObject(QObject *g); + bool isNull() const noexcept { return !o; } }; class QObject; template<class T> -class QQmlGuard : private QQmlGuardImpl +class QQmlGuard : protected QQmlGuardImpl { friend class QQmlData; public: - inline QQmlGuard(); - inline QQmlGuard(T *); - inline QQmlGuard(const QQmlGuard<T> &); - inline virtual ~QQmlGuard(); + Q_NODISCARD_CTOR inline QQmlGuard(); + Q_NODISCARD_CTOR inline QQmlGuard(ObjectDestroyedFn objectDestroyed, T *); + Q_NODISCARD_CTOR inline QQmlGuard(T *); + Q_NODISCARD_CTOR inline QQmlGuard(const QQmlGuard<T> &); inline QQmlGuard<T> &operator=(const QQmlGuard<T> &o); inline QQmlGuard<T> &operator=(T *); - inline T *object() const; - inline void setObject(T *g); + T *object() const noexcept { return static_cast<T *>(o); } + void setObject(T *g) { QQmlGuardImpl::setObject(g); } - inline bool isNull() const - { return !o; } + using QQmlGuardImpl::isNull; - 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 *) {} + T *operator->() const noexcept { return object(); } + T &operator*() const { return *object(); } + operator T *() const noexcept { return object(); } + T *data() const noexcept { return object(); } }; +/* used in QQmlStrongJSQObjectReference to indicate that the + * object has JS ownership + * We save it in objectDestroyFn to save space + * (implemented in qqmlengine.cpp) + */ +void Q_QML_EXPORT hasJsOwnershipIndicator(QQmlGuardImpl *); + template <typename T> -class QQmlStrongJSQObjectReference : public QQmlGuard<T> +class QQmlStrongJSQObjectReference final : protected QQmlGuardImpl { public: - void setObject(T *o, QObject *parent) { - T *old = this->object(); - if (o == old) + T *object() const noexcept { return static_cast<T *>(o); } + + using QQmlGuardImpl::isNull; + + T *operator->() const noexcept { return object(); } + T &operator*() const { return *object(); } + operator T *() const noexcept { return object(); } + T *data() const noexcept { return object(); } + + void setObject(T *obj, QObject *parent) { + T *old = object(); + if (obj == old) return; - if (m_jsOwnership && old && old->parent() == parent) + if (hasJsOwnership() && old && old->parent() == parent) QQml_setParent_noEvent(old, nullptr); - this->QQmlGuard<T>::operator=(o); + QQmlGuardImpl::setObject(obj); - if (o && !o->parent() && !QQmlData::keepAliveDuringGarbageCollection(o)) { - m_jsOwnership = true; - QQml_setParent_noEvent(o, parent); + if (obj && !obj->parent() && !QQmlData::keepAliveDuringGarbageCollection(obj)) { + setJsOwnership(true); + QQml_setParent_noEvent(obj, parent); } else { - m_jsOwnership = false; + setJsOwnership(false); } } private: - using QQmlGuard<T>::setObject; - using QQmlGuard<T>::operator=; - bool m_jsOwnership = false; + bool hasJsOwnership() { + return objectDestroyed == hasJsOwnershipIndicator; + } + + void setJsOwnership(bool itHasOwnership) { + objectDestroyed = itHasOwnership ? hasJsOwnershipIndicator : nullptr; + } }; QT_END_NAMESPACE @@ -150,8 +133,15 @@ QQmlGuardImpl::QQmlGuardImpl(QObject *g) if (o) addGuard(); } +/* + \internal + Copying a QQmlGuardImpl leaves the old one in the intrinsic linked list of guards. + The fresh copy does not contain the list pointer of the existing guard; instead + only the object and objectDestroyed pointers are copied, and if there is an object + we add the new guard to the object's list of guards. + */ QQmlGuardImpl::QQmlGuardImpl(const QQmlGuardImpl &g) -: o(g.o) +: o(g.o), objectDestroyed(g.objectDestroyed) { if (o) addGuard(); } @@ -192,25 +182,28 @@ QQmlGuard<T>::QQmlGuard() } template<class T> -QQmlGuard<T>::QQmlGuard(T *g) -: QQmlGuardImpl(g) +QQmlGuard<T>::QQmlGuard(ObjectDestroyedFn objDestroyed, T *obj) + : QQmlGuardImpl(obj) { + objectDestroyed = objDestroyed; } template<class T> -QQmlGuard<T>::QQmlGuard(const QQmlGuard<T> &g) +QQmlGuard<T>::QQmlGuard(T *g) : QQmlGuardImpl(g) { } template<class T> -QQmlGuard<T>::~QQmlGuard() +QQmlGuard<T>::QQmlGuard(const QQmlGuard<T> &g) +: QQmlGuardImpl(g) { } template<class T> QQmlGuard<T> &QQmlGuard<T>::operator=(const QQmlGuard<T> &g) { + objectDestroyed = g.objectDestroyed; setObject(g.object()); return *this; } @@ -218,18 +211,15 @@ QQmlGuard<T> &QQmlGuard<T>::operator=(const QQmlGuard<T> &g) template<class T> QQmlGuard<T> &QQmlGuard<T>::operator=(T *g) { + /* this does not touch objectDestroyed, as operator= is only a convenience + * for setObject. All logic involving objectDestroyed is (sub-)class specific + * and remains unaffected. + */ setObject(g); return *this; } -template<class T> -T *QQmlGuard<T>::object() const -{ - return static_cast<T *>(o); -} - -template<class T> -void QQmlGuard<T>::setObject(T *g) +void QQmlGuardImpl::setObject(QObject *g) { if (g != o) { if (prev) remGuard(); |