// // This file is part of Kepka, // an unofficial desktop version of Telegram messaging app, // see https://github.com/procxx/kepka // // Kepka is free software: you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // It is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // In addition, as a special exception, the copyright holders give permission // to link the code of portions of this program with the OpenSSL library. // // Full license: https://github.com/procxx/kepka/blob/master/LICENSE // Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org // Copyright (c) 2017- Kepka Contributors, https://github.com/procxx // #pragma once #include <memory> // @todo replace this with std::experimental::observer_ptr #include <QCoreApplication> #include <utility> namespace base { class enable_weak_from_this; template <typename T> class weak_unique_ptr; class enable_weak_from_this { public: enable_weak_from_this() = default; enable_weak_from_this(const enable_weak_from_this &other) noexcept {} enable_weak_from_this(enable_weak_from_this &&other) noexcept {} enable_weak_from_this &operator=(const enable_weak_from_this &other) noexcept { return *this; } enable_weak_from_this &operator=(enable_weak_from_this &&other) noexcept { return *this; } private: template <typename Child> friend class weak_unique_ptr; std::shared_ptr<enable_weak_from_this *> getGuarded() const { if (!_guarded) { _guarded = std::make_shared<enable_weak_from_this *>( const_cast<enable_weak_from_this *>(static_cast<const enable_weak_from_this *>(this))); } return _guarded; } mutable std::shared_ptr<enable_weak_from_this *> _guarded; }; template <typename T> class weak_unique_ptr { public: weak_unique_ptr() = default; weak_unique_ptr(T *value) : _guarded(value ? value->getGuarded() : std::shared_ptr<enable_weak_from_this *>()) {} weak_unique_ptr(const std::unique_ptr<T> &value) : weak_unique_ptr(value.get()) {} weak_unique_ptr &operator=(T *value) { _guarded = value ? value->getGuarded() : std::shared_ptr<enable_weak_from_this *>(); return *this; } weak_unique_ptr &operator=(const std::unique_ptr<T> &value) { return (*this = value.get()); } T *get() const noexcept { if (auto shared = _guarded.lock()) { return static_cast<T *>(*shared); } return nullptr; } explicit operator bool() const noexcept { return !!_guarded.lock(); } T &operator*() const noexcept { return *get(); } T *operator->() const noexcept { return get(); } private: std::weak_ptr<enable_weak_from_this *> _guarded; }; template <typename T> inline bool operator==(const weak_unique_ptr<T> &pointer, std::nullptr_t) { return (pointer.get() == nullptr); } template <typename T> inline bool operator==(std::nullptr_t, const weak_unique_ptr<T> &pointer) { return (pointer == nullptr); } template <typename T> inline bool operator!=(const weak_unique_ptr<T> &pointer, std::nullptr_t) { return !(pointer == nullptr); } template <typename T> inline bool operator!=(std::nullptr_t, const weak_unique_ptr<T> &pointer) { return !(pointer == nullptr); } template <typename T> weak_unique_ptr<T> make_weak_unique(T *value) { return weak_unique_ptr<T>(value); } template <typename T> weak_unique_ptr<T> make_weak_unique(const std::unique_ptr<T> &value) { return weak_unique_ptr<T>(value); } } // namespace base #ifdef QT_VERSION template <typename Lambda> inline void InvokeQueued(base::enable_weak_from_this *context, Lambda &&lambda) { QObject proxy; QObject::connect(&proxy, &QObject::destroyed, QCoreApplication::instance(), [guard = base::make_weak_unique(context), lambda = std::forward<Lambda>(lambda)] { if (guard) { lambda(); } }, Qt::QueuedConnection); } #endif // QT_VERSION