managedloadsavethread.h

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/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2006-01-16
 * Description : image file IO threaded interface.
 *
 * Copyright (C) 2005-2013 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
 * Copyright (C) 2005-2022 by Gilles Caulier <caulier dot gilles at gmail dot com>
 *
 * This program 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 2, or (at your option)
 * any later version.
 *
 * This program 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.
 *
 * ============================================================ */
 
#ifndef DIGIKAM_MANAGED_LOAD_SAVE_THREAD_H
#define DIGIKAM_MANAGED_LOAD_SAVE_THREAD_H
 
// Local includes
 
#include "loadsavethread.h"
 
namespace Digikam
{
 
class LoadingTask;
class LoadSaveTask;
 
class DIGIKAM_EXPORT ManagedLoadSaveThread : public LoadSaveThread
{
    Q_OBJECT
 
public:
 
    enum LoadingPolicy
    {
        LoadingPolicyFirstRemovePrevious,
        LoadingPolicyPrepend,
        LoadingPolicySimplePrepend,
        LoadingPolicyAppend,
        LoadingPolicySimpleAppend,
        LoadingPolicyPreload
    };
 
    enum TerminationPolicy
    {
        TerminationPolicyTerminateLoading,
        TerminationPolicyTerminatePreloading,
        TerminationPolicyWait,
        TerminationPolicyTerminateAll
    };
 
    enum LoadingTaskFilter
    {
        LoadingTaskFilterAll,
        LoadingTaskFilterPreloading
    };
 
    enum LoadingMode
    {
        LoadingModeNormal,
        LoadingModeShared
    };
 
public:
 
    explicit ManagedLoadSaveThread(QObject* const parent = nullptr);
    ~ManagedLoadSaveThread() override;
 
    void load(const LoadingDescription& description);
    void load(const LoadingDescription& description, LoadingPolicy policy);
 
    void stopLoading(const QString& filePath = QString(),
                     LoadingTaskFilter filter = LoadingTaskFilterAll);
 
    void stopLoading(const LoadingDescription& desc,
                     LoadingTaskFilter filter = LoadingTaskFilterAll);
 
    void stopSaving(const QString& filePath = QString());
 
    void stopAllTasks();
 
    void save(DImg& image, const QString& filePath, const QString& format);
 
    void              setTerminationPolicy(TerminationPolicy terminationPolicy);
    TerminationPolicy terminationPolicy()                                               const;
 
    void          setLoadingPolicy(LoadingPolicy policy);
    LoadingPolicy loadingPolicy()                                                       const;
 
protected:
 
    void shutDown();
 
    void load(const LoadingDescription& description, LoadingMode loadingMode,
              AccessMode mode = AccessModeReadWrite);
 
    void load(const LoadingDescription& description, LoadingMode loadingMode,
              LoadingPolicy policy, AccessMode mode = AccessModeReadWrite);
 
    void loadPreview(const LoadingDescription& description, LoadingPolicy policy);
    void loadThumbnail(const LoadingDescription& description);
 
    void preloadThumbnail(const LoadingDescription& description);
    void preloadThumbnailGroup(const QList<LoadingDescription>& descriptions);
    void prependThumbnailGroup(const QList<LoadingDescription>& descriptions);
 
protected:
 
    LoadingPolicy     m_loadingPolicy;
    TerminationPolicy m_terminationPolicy;
 
private:
 
    LoadingTask* checkLoadingTask(LoadSaveTask* const task, LoadingTaskFilter filter)   const;
    LoadingTask* findExistingTask(const LoadingDescription& description)                const;
    LoadingTask* createLoadingTask(const LoadingDescription& description,
                                   bool preloading,
                                   LoadingMode loadingMode,
                                   AccessMode accessMode);
 
    void removeLoadingTasks(const LoadingDescription& description, LoadingTaskFilter filter);
 
private:
 
    // Disable
    ManagedLoadSaveThread(const ManagedLoadSaveThread&)            = delete;
    ManagedLoadSaveThread& operator=(const ManagedLoadSaveThread&) = delete;
};
 
} // namespace Digikam
 
#endif // DIGIKAM_MANAGED_LOAD_SAVE_THREAD_H