kis_async_action_feedback.h

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/*
 *  SPDX-FileCopyrightText: 2016 Dmitry Kazakov <dimula73@gmail.com>
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 */
 
#ifndef __KIS_ASYNC_ACTION_FEEDBACK_H
#define __KIS_ASYNC_ACTION_FEEDBACK_H
 
#include <QScopedPointer>
#include <functional>
#include "KisImportExportFilter.h"
 
class QWidget;
class QMutex;
 
class KisAsyncActionFeedback
{
private:
    struct DefaultWaitingMessageCallback {
        QString operator()() const;
    };
 
public:
    KisAsyncActionFeedback(const QString &message, QWidget *parent);
    ~KisAsyncActionFeedback();
 
    KisImportExportErrorCode runAction(std::function<KisImportExportErrorCode()> func);
    void runVoidAction(std::function<void()> func);
 
    template <typename Mutex>
    void waitForMutex(Mutex &mutex) {
        waitForMutexLikeImpl(std::make_unique<MutexLike<Mutex>>(mutex));
    }
 
    template<typename Mutex, typename CallbackFunc = DefaultWaitingMessageCallback>
    class MutexWrapper : public Mutex
    {
    public:
        template<typename ...Args>
        MutexWrapper(Args ...args)
            : Mutex(args...)
        {
        }
 
        void lock() {
            if (!Mutex::try_lock()) {
                KisAsyncActionFeedback f(CallbackFunc{}(), 0);
                f.waitForMutex(static_cast<Mutex&>(*this));
                Mutex::lock();
            }
        }
    };
 
private:
 
    struct MutexLikeBase
    {
        virtual ~MutexLikeBase() = default;
        virtual void lock() = 0;
        virtual void unlock() = 0;
        virtual bool try_lock() = 0;
    };
 
    template <typename T>
    struct MutexLike : MutexLikeBase
    {
        MutexLike(T& m) : mutex(m) {}
 
        T &mutex;
 
        void lock() override {
            mutex.lock();
        }
        void unlock() override {
            mutex.unlock();
        }
        bool try_lock() override {
            return mutex.try_lock();
        }
    };
 
    void waitForMutexLikeImpl(std::unique_ptr<MutexLikeBase> &&mutex);
 
private:
    struct Private;
    const QScopedPointer<Private> m_d;
};
 
#endif /* __KIS_ASYNC_ACTION_FEEDBACK_H */