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Diffstat (limited to 'src/libs/threadimageio/managedloadsavethread.h')
-rw-r--r-- | src/libs/threadimageio/managedloadsavethread.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/src/libs/threadimageio/managedloadsavethread.h b/src/libs/threadimageio/managedloadsavethread.h new file mode 100644 index 00000000..ec6a563c --- /dev/null +++ b/src/libs/threadimageio/managedloadsavethread.h @@ -0,0 +1,134 @@ +/* ============================================================ + * + * This file is a part of digiKam project + * http://www.digikam.org + * + * Date : 2006-01-16 + * Description : image file IO threaded interface. + * + * Copyright (C) 2005-2007 by Marcel Wiesweg <[email protected]> + * Copyright (C) 2005-2007 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 MANAGED_LOAD_SAVE_THREAD_H +#define MANAGED_LOAD_SAVE_THREAD_H + +#include "loadsavethread.h" + +namespace Digikam +{ + +class LoadingTask; + +class DIGIKAM_EXPORT ManagedLoadSaveThread : public LoadSaveThread +{ + +public: + + // Termination is controlled by setting the TerminationPolicy + // Default is TerminationPolicyTerminateLoading + ManagedLoadSaveThread(); + ~ManagedLoadSaveThread(); + + enum LoadingPolicy + { + // Load image immediately, remove and stop all previous loading tasks. + LoadingPolicyFirstRemovePrevious, + // Prepend loading in front of all other tasks, but wait for the current task to finish. + // No other tasks will be removed, preloading tasks will be stopped and postponed. + LoadingPolicyPrepend, + // Append loading task to the end of the list, but in front of all preloading tasks. + // No other tasks will be removed, preloading tasks will be stopped and postponed. + // This is similar to the simple load() operation from LoadSaveThread, except for the + // special care taken for preloading. + LoadingPolicyAppend, + // Preload image, i.e. load it with low priority when no other tasks are scheduled. + // All other tasks will take precedence, and preloading tasks will be stopped and + // postponed when another task is added. + // No progress info will be sent for preloaded images + LoadingPolicyPreload + }; + + enum TerminationPolicy + { + // Wait for saving tasks, stop and remove loading tasks + // This is the default. + TerminationPolicyTerminateLoading, + // Wait for loading and saving tasks, stop and remove preloading tasks + TerminationPolicyTerminatePreloading, + // Wait for all pending tasks + TerminationPolicyWait + }; + + enum LoadingTaskFilter + { + // filter all loading tasks + LoadingTaskFilterAll, + // filter only tasks with preloading policy + LoadingTaskFilterPreloading + }; + + // used by SharedLoadSaveThread only + enum LoadingMode + { + // no sharing of loading process, no caching of image + LoadingModeNormal, + // loading process is shared, image is cached + LoadingModeShared + }; + + // Append a task to load the given file to the task list. + // If there is already a task for the given file, it will possibly be rescheduled, + // but no second task will be added. + // Only loading tasks will - if required by the policy - be stopped or removed, + // saving tasks will not be touched. + void load(LoadingDescription description, LoadingPolicy policy = LoadingPolicyAppend); + + // Stop and remove tasks filtered by filePath and policy. + // If filePath isNull, applies to all file paths. + void stopLoading(const TQString& filePath = TQString(), LoadingTaskFilter filter = LoadingTaskFilterAll); + + // Same than previous method, but Stop and remove tasks filtered by LoadingDescription. + void stopLoading(const LoadingDescription& desc, LoadingTaskFilter filter = LoadingTaskFilterAll); + + // Stop and remove saving tasks filtered by filePath. + // If filePath isNull, applies to all file paths. + void stopSaving(const TQString& filePath = TQString()); + + // Append a task to save the image to the task list + void save(DImg &image, const TQString& filePath, const TQString &format); + + void setTerminationPolicy(TerminationPolicy terminationPolicy); + +protected: + + void load(LoadingDescription description, LoadingMode loadingMode, + LoadingPolicy policy = LoadingPolicyAppend, AccessMode mode = AccessModeReadWrite); + void loadPreview(LoadingDescription description); + +private: + + LoadingTask *checkLoadingTask(class LoadSaveTask *task, LoadingTaskFilter filter); + LoadingTask *findExistingTask(const LoadingDescription &description); + LoadingTask *createLoadingTask(const LoadingDescription &description, bool preloading, LoadingMode loadingMode, AccessMode accessMode); + void removeLoadingTasks(const LoadingDescription &description, LoadingTaskFilter filter); + + TerminationPolicy m_terminationPolicy; +}; + +} // namespace Digikam + + +#endif // MANAGED_LOAD_SAVE_THREAD_H |