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Diffstat (limited to 'src/qmlcompiler/qdeferredpointer_p.h')
| -rw-r--r-- | src/qmlcompiler/qdeferredpointer_p.h | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/qmlcompiler/qdeferredpointer_p.h b/src/qmlcompiler/qdeferredpointer_p.h new file mode 100644 index 0000000000..07875013fa --- /dev/null +++ b/src/qmlcompiler/qdeferredpointer_p.h @@ -0,0 +1,181 @@ +/**************************************************************************** +** +** Copyright (C) 2020 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the tools applications of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:GPL-EXCEPT$ +** 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 General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3 as published by the Free Software +** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT +** 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-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QDEFERREDPOINTER_P_H +#define QDEFERREDPOINTER_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 <QtCore/qglobal.h> +#include <QtCore/qsharedpointer.h> + +QT_BEGIN_NAMESPACE + +template<typename T> +class QDeferredFactory +{ +public: + T create() const; + bool isValid() const; + void clear(); +}; + +template<typename T> +class QDeferredWeakPointer; + +template<typename T> +class QDeferredSharedPointer +{ +public: + using Factory = QDeferredFactory<std::remove_const_t<T>>; + + QDeferredSharedPointer() = default; + + QDeferredSharedPointer(QSharedPointer<T> data) + : m_data(data) + {} + + QDeferredSharedPointer(QWeakPointer<T> data) + : m_data(data) + {} + + QDeferredSharedPointer(QSharedPointer<T> data, QSharedPointer<Factory> factory) + : m_data(data), m_factory(factory) + {} + + operator QSharedPointer<T>() const + { + if (m_factory && m_factory->isValid()) { + const_cast<std::remove_const_t<T> &>(*m_data) = m_factory->create(); + m_factory->clear(); + } + return m_data; + } + + operator QDeferredSharedPointer<const T>() const { return { m_data, m_factory }; } + + T &operator*() const { return QSharedPointer<T>(*this).operator*(); } + T *operator->() const { return QSharedPointer<T>(*this).operator->(); } + + bool isNull() const { return m_data.isNull(); } + explicit operator bool() const noexcept { return !isNull(); } + bool operator !() const noexcept { return isNull(); } + + T *data() const { return QSharedPointer<T>(*this).data(); } + + friend qsizetype qHash(const QDeferredSharedPointer &ptr, qsizetype seed = 0) + { + return qHashMulti(seed, ptr.m_factory, ptr.m_data); + } + + friend bool operator==(const QDeferredSharedPointer &a, const QDeferredSharedPointer &b) + { + return a.m_factory == b.m_factory && a.m_data == b.m_data; + } + +private: + friend class QDeferredWeakPointer<T>; + + QSharedPointer<T> m_data; + QSharedPointer<Factory> m_factory; +}; + +template<typename T> +class QDeferredWeakPointer +{ +public: + using Factory = QDeferredFactory<std::remove_const_t<T>>; + + QDeferredWeakPointer() = default; + + QDeferredWeakPointer(const QDeferredSharedPointer<T> &strong) + : m_data(strong.m_data), m_factory(strong.m_factory) + { + } + + QDeferredWeakPointer(QWeakPointer<T> data, QWeakPointer<Factory> factory) + : m_data(data), m_factory(factory) + {} + + operator QWeakPointer<T>() const + { + if (m_factory) { + auto factory = m_factory.toStrongRef(); + if (factory->isValid()) { + const_cast<std::remove_const_t<T> &>(*(m_data.toStrongRef())) = factory->create(); + factory->clear(); + } + } + return m_data; + } + + operator QDeferredSharedPointer<T>() const + { + return QDeferredSharedPointer<T>(m_data.toStrongRef(), m_factory.toStrongRef()); + } + + operator QDeferredWeakPointer<const T>() const { return {m_data, m_factory}; } + + QSharedPointer<T> toStrongRef() const + { + return QWeakPointer<T>(*this).toStrongRef(); + } + + bool isNull() const { return m_data.isNull(); } + explicit operator bool() const noexcept { return !isNull(); } + bool operator !() const noexcept { return isNull(); } + + T *data() const { return QWeakPointer<T>(*this).data(); } + + friend qsizetype qHash(const QDeferredWeakPointer &ptr, qsizetype seed = 0) + { + return qHashMulti(seed, ptr.m_factory, ptr.m_data); + } + + friend bool operator==(const QDeferredWeakPointer &a, const QDeferredWeakPointer &b) + { + return a.m_factory == b.m_factory && a.m_data == b.m_data; + } + +private: + QWeakPointer<T> m_data; + QWeakPointer<Factory> m_factory; +}; + + +QT_END_NAMESPACE + +#endif // QDEFERREDPOINTER_P_H |