src/kitemviews/kfileitemmodelrolesupdater.h

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #ifndef KFILEITEMMODELROLESUPDATER_H
  21 #define KFILEITEMMODELROLESUPDATER_H
  22
  23 #include <libdolphin_export.h>
  24
  25 #include <KFileItem>
  26 #include <kitemviews/kitemmodelbase.h>
  27
  28 #include <QObject>
  29 #include <QSet>
  30 #include <QSize>
  31 #include <QStringList>
  32
  33 class KFileItemModel;
  34 class KJob;
  35 class QPixmap;
  36 class QTimer;
  37
  38 /**
  39  * @brief Resolves expensive roles asynchronously and applies them to the KFileItemModel.
  40  *
  41  * KFileItemModel only resolves roles that are inexpensive like e.g. the file name or
  42  * the permissions. Creating previews or determining the MIME-type can be quite expensive
  43  * and KFileItemModelRolesUpdater takes care to update such roles asynchronously.
  44  */
  45 class LIBDOLPHINPRIVATE_EXPORT KFileItemModelRolesUpdater : public QObject
  46 {
  47     Q_OBJECT
  48
  49 public:
  50     explicit KFileItemModelRolesUpdater(KFileItemModel* model, QObject* parent = 0);
  51     virtual ~KFileItemModelRolesUpdater();
  52
  53     void setIconSize(const QSize& size);
  54     QSize iconSize() const;
  55
  56     /**
  57      * Sets the range of items that are visible currently. The roles
  58      * of visible items are resolved first.
  59      */
  60     void setVisibleIndexRange(int index, int count);
  61
  62     /**
  63      * If \a show is set to true, the "iconPixmap" role will be filled with a preview
  64      * of the file. If \a show is false the MIME type icon will be used for the "iconPixmap"
  65      * role.
  66      */
  67     void setPreviewShown(bool show);
  68     bool isPreviewShown() const;
  69
  70     /**
  71      * If \a paused is set to true the asynchronous resolving of roles will be paused.
  72      * State changes during pauses like changing the icon size or the preview-shown
  73      * will be remembered and handled after unpausing.
  74      */
  75     void setPaused(bool paused);
  76     bool isPaused() const;
  77
  78     /**
  79      * Sets the roles that should be resolved asynchronously.
  80      */
  81     void setRoles(const QSet<QByteArray>& roles);
  82     QSet<QByteArray> roles() const;
  83
  84     /**
  85      * Sets the list of enabled thumbnail plugins.
  86      * Per default all plugins enabled in the KConfigGroup "PreviewSettings"
  87      * are used.
  88      *
  89      * Note that this method doesn't cause already generated previews
  90      * to be regenerated.
  91      *
  92      * For a list of available plugins, call KServiceTypeTrader::self()->query("ThumbCreator").
  93      *
  94      * @see enabledPlugins
  95      */
  96     void setEnabledPlugins(const QStringList& list);
  97
  98     /**
  99      * Returns the list of enabled thumbnail plugins.
 100      * @see setEnabledPlugins
 101      */
 102     QStringList enabledPlugins() const;
 103
 104 private slots:
 105     void slotItemsInserted(const KItemRangeList& itemRanges);
 106     void slotItemsRemoved(const KItemRangeList& itemRanges);
 107     void slotItemsChanged(const KItemRangeList& itemRanges,
 108                           const QSet<QByteArray>& roles);
 109
 110     /**
 111      * Is invoked after a preview has been received successfully.
 112      * @see startPreviewJob()
 113      */
 114     void slotGotPreview(const KFileItem& item, const QPixmap& pixmap);
 115
 116     /**
 117      * Is invoked after generating a preview has failed.
 118      * @see startPreviewJob()
 119      */
 120     void slotPreviewFailed(const KFileItem& item);
 121
 122     /**
 123      * Is invoked when the preview job has been finished and
 124      * removes the job from the m_previewJobs list.
 125      * @see startPreviewJob()
 126      */
 127     void slotPreviewJobFinished(KJob* job);
 128
 129     void resolvePendingRoles();
 130     void resolveNextPendingRoles();
 131
 132 private:
 133     /**
 134      * Updates the roles for the given item ranges. The roles for the currently
 135      * visible items will get updated first.
 136      */
 137     void startUpdating(const KItemRangeList& itemRanges);
 138
 139     /**
 140      * Creates previews for the items starting from the first item of the
 141      * given list.
 142      * @see slotGotPreview()
 143      * @see slotPreviewFailed()
 144      * @see slotPreviewJobFinished()
 145      */
 146     void startPreviewJob(const KFileItemList& items);
 147
 148     bool hasPendingRoles() const;
 149     void resetPendingRoles();
 150     void triggerPendingRolesResolving(int count);
 151     void sortAndResolveAllRoles();
 152     void sortAndResolvePendingRoles();
 153
 154     enum ResolveHint {
 155         ResolveFast,
 156         ResolveAll
 157     };
 158     bool applyResolvedRoles(const KFileItem& item, ResolveHint hint);
 159     QHash<QByteArray, QVariant> rolesData(const KFileItem& item) const;
 160
 161     KFileItemList sortedItems(const QSet<KFileItem>& items) const;
 162
 163     static int subDirectoriesCount(const QString& path);
 164
 165 private:
 166     // Property for setPaused()/isPaused().
 167     bool m_paused;
 168
 169     // Property changes during pausing must be remembered to be able
 170     // to react when unpausing again:
 171     bool m_previewChangedDuringPausing;
 172     bool m_iconSizeChangedDuringPausing;
 173     bool m_rolesChangedDuringPausing;
 174
 175     // Property for setPreviewShown()/previewShown().
 176     bool m_previewShown;
 177
 178     // True if the role "iconPixmap" should be cleared when resolving the next
 179     // role with resolveRole(). Is necessary if the preview gets disabled
 180     // during the roles-updater has been paused by setPaused().
 181     bool m_clearPreviews;
 182
 183     KFileItemModel* m_model;
 184     QSize m_iconSize;
 185     int m_firstVisibleIndex;
 186     int m_lastVisibleIndex;
 187     QSet<QByteArray> m_roles;
 188     QStringList m_enabledPlugins;
 189
 190     QSet<KFileItem> m_pendingVisibleItems;
 191     QSet<KFileItem> m_pendingInvisibleItems;
 192     QList<KJob*> m_previewJobs;
 193
 194     QTimer* m_resolvePendingRolesTimer;
 195 };
 196
 197 #endif
 198
 199