File indexing completed on 2024-09-15 12:00:06

 /*
     SPDX-FileCopyrightText: 2008-2009 Peter Penz <peter.penz@gmx.at>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #ifndef KFILEPREVIEWGENERATOR_H
 #define KFILEPREVIEWGENERATOR_H
 
 #include "kiofilewidgets_export.h"
 
 #include <QObject>
 
 #include <memory>
 
 class KAbstractViewAdapter;
 class KDirModel;
 class QAbstractItemView;
 class QAbstractProxyModel;
 
 class KFilePreviewGeneratorPrivate;
 
 /**
  * @class KFilePreviewGenerator kfilepreviewgenerator.h <KFilePreviewGenerator>
  *
  * @brief Generates previews for files of an item view.
  *
  * Per default a preview is generated for each item.
  * Additionally the clipboard is checked for cut items.
  * The icon state for cut items gets dimmed automatically.
  *
  * The following strategy is used when creating previews:
  * - The previews for currently visible items are created before
  *   the previews for invisible items.
  * - If the user changes the visible area by using the scrollbars,
  *   all pending previews get paused. As soon as the user stays
  *   on the same position for a short delay, the previews are
  *   resumed. Also in this case the previews for the visible items
  *   are generated first.
  *
  * @since 4.2
  */
 class KIOFILEWIDGETS_EXPORT KFilePreviewGenerator : public QObject
 {
     Q_OBJECT
 
 public:
     /**
      * @param parent  Item view containing the file items where previews should
      *                be generated. It is mandatory that the item view specifies
      *                an icon size by QAbstractItemView::setIconSize() and that
      *                the model of the view (or the source model of the proxy model)
      *                is an instance of KDirModel. Otherwise no previews will be generated.
      */
     KFilePreviewGenerator(QAbstractItemView *parent);
 
     /** @internal */
     KFilePreviewGenerator(KAbstractViewAdapter *parent, QAbstractProxyModel *model);
 
     ~KFilePreviewGenerator() override;
 
     /**
      * If \a show is set to true, a preview is generated for each item. If \a show
      * is false, the MIME type icon of the item is shown instead. Per default showing
      * the preview is turned on. Note that it is mandatory that the item view
      * specifies an icon size by QAbstractItemView::setIconSize(), otherwise
      * KFilePreviewGenerator::isPreviewShown() will always return false.
      */
     void setPreviewShown(bool show);
     bool isPreviewShown() const;
 
 #if KIOFILEWIDGETS_ENABLE_DEPRECATED_SINCE(4, 3)
     /**
      * @deprecated Since 4.3, use KFilePreviewGenerator::updateIcons() instead.
      */
     KIOFILEWIDGETS_DEPRECATED_VERSION(4, 3, "Use KFilePreviewGenerator::updateIcons()")
     void updatePreviews();
 #endif
 
     /**
      * Sets the list of enabled thumbnail plugins.
      * Per default all plugins enabled in the KConfigGroup "PreviewSettings"
      * are used.
      *
      * Note that this method doesn't cause already generated previews
      * to be regenerated.
      *
      * For a list of available plugins, call KIO::PreviewJob::availableThumbnailerPlugins().
      *
      * @see enabledPlugins
      */
     void setEnabledPlugins(const QStringList &list);
 
     /**
      * Returns the list of enabled thumbnail plugins.
      * @see setEnabledPlugins
      */
     QStringList enabledPlugins() const;
 
 public Q_SLOTS:
     /**
      * Updates the icons for all items. Usually it is only
      * necessary to invoke this method when the icon size of the abstract item view
      * has been changed by QAbstractItemView::setIconSize(). Note that this method
      * should also be invoked if previews have been turned off, as the icons for
      * cut items must be updated when the icon size has changed.
      * @since 4.3
      */
     void updateIcons();
 
     /** Cancels all pending previews. */
     void cancelPreviews();
 
 private:
     friend class KFilePreviewGeneratorPrivate;
     std::unique_ptr<KFilePreviewGeneratorPrivate> const d;
 
     Q_DISABLE_COPY(KFilePreviewGenerator)
 
     Q_PRIVATE_SLOT(d, void pauseIconUpdates())
 };
 
 #endif