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 <config-nepomuk.h>
  24
  25 #include <KFileItem>
  26 #include <kitemviews/kitemmodelbase.h>
  27
  28 #include <libdolphin_export.h>
  29
  30 #include <QObject>
  31 #include <QSet>
  32 #include <QSize>
  33 #include <QStringList>
  34
  35 class KDirWatch;
  36 class KFileItemModel;
  37 class KJob;
  38 class QPixmap;
  39 class QTimer;
  40
  41 #ifdef HAVE_NEPOMUK
  42     namespace Nepomuk2
  43     {
  44         class ResourceWatcher;
  45         class Resource;
  46     }
  47 #else
  48     // Required for the slot applyChangedNepomukRoles() that
  49     // cannot be ifdefined due to moc.
  50     namespace Nepomuk2
  51     {
  52         class Resource;
  53     }
  54 #endif
  55
  56 /**
  57  * @brief Resolves expensive roles asynchronously and applies them to the KFileItemModel.
  58  *
  59  * KFileItemModel only resolves roles that are inexpensive like e.g. the file name or
  60  * the permissions. Creating previews or determining the MIME-type can be quite expensive
  61  * and KFileItemModelRolesUpdater takes care to update such roles asynchronously.
  62  */
  63 class LIBDOLPHINPRIVATE_EXPORT KFileItemModelRolesUpdater : public QObject
  64 {
  65     Q_OBJECT
  66
  67 public:
  68     explicit KFileItemModelRolesUpdater(KFileItemModel* model, QObject* parent = 0);
  69     virtual ~KFileItemModelRolesUpdater();
  70
  71     void setIconSize(const QSize& size);
  72     QSize iconSize() const;
  73
  74     /**
  75      * Sets the range of items that are visible currently. The roles
  76      * of visible items are resolved first.
  77      */
  78     void setVisibleIndexRange(int index, int count);
  79
  80     void setMaximumVisibleItems(int count);
  81
  82     /**
  83      * If \a show is set to true, the "iconPixmap" role will be filled with a preview
  84      * of the file. If \a show is false the MIME type icon will be used for the "iconPixmap"
  85      * role.
  86      */
  87     void setPreviewsShown(bool show);
  88     bool previewsShown() const;
  89
  90     /**
  91      * If enabled a small preview gets upscaled to the icon size in case where
  92      * the icon size is larger than the preview. Per default enlarging is
  93      * enabled.
  94      */
  95     void setEnlargeSmallPreviews(bool enlarge);
  96     bool enlargeSmallPreviews() const;
  97
  98     /**
  99      * If \a paused is set to true the asynchronous resolving of roles will be paused.
 100      * State changes during pauses like changing the icon size or the preview-shown
 101      * will be remembered and handled after unpausing.
 102      */
 103     void setPaused(bool paused);
 104     bool isPaused() const;
 105
 106     /**
 107      * Sets the roles that should be resolved asynchronously.
 108      */
 109     void setRoles(const QSet<QByteArray>& roles);
 110     QSet<QByteArray> roles() const;
 111
 112     /**
 113      * Sets the list of enabled thumbnail plugins that are used for previews.
 114      * Per default all plugins enabled in the KConfigGroup "PreviewSettings"
 115      * are used.
 116      *
 117      * For a list of available plugins, call KServiceTypeTrader::self()->query("ThumbCreator").
 118      *
 119      * @see enabledPlugins
 120      */
 121     void setEnabledPlugins(const QStringList& list);
 122
 123     /**
 124      * Returns the list of enabled thumbnail plugins.
 125      * @see setEnabledPlugins
 126      */
 127     QStringList enabledPlugins() const;
 128
 129 private slots:
 130     void slotItemsInserted(const KItemRangeList& itemRanges);
 131     void slotItemsRemoved(const KItemRangeList& itemRanges);
 132     void slotItemsChanged(const KItemRangeList& itemRanges,
 133                           const QSet<QByteArray>& roles);
 134     void slotSortRoleChanged(const QByteArray& current,
 135                              const QByteArray& previous);
 136
 137     /**
 138      * Is invoked after a preview has been received successfully.
 139      * @see startPreviewJob()
 140      */
 141     void slotGotPreview(const KFileItem& item, const QPixmap& pixmap);
 142
 143     /**
 144      * Is invoked after generating a preview has failed.
 145      * @see startPreviewJob()
 146      */
 147     void slotPreviewFailed(const KFileItem& item);
 148
 149     /**
 150      * Is invoked when the preview job has been finished and
 151      * removes the job from the m_previewJobs list.
 152      * @see startPreviewJob()
 153      */
 154     void slotPreviewJobFinished(KJob* job);
 155
 156     void resolveNextPendingRoles();
 157
 158     /**
 159      * Resolves items that have not been resolved yet after the change has been
 160      * notified by slotItemsChanged(). Is invoked if the m_changedItemsTimer
 161      * exceeds.
 162      */
 163     void resolveChangedItems();
 164
 165     void applyChangedNepomukRoles(const Nepomuk2::Resource& resource);
 166
 167     /**
 168      * Is invoked if a directory watched by KDirWatch got dirty. Updates
 169      * the "isExpandable"- and "size"-roles of the item that matches to
 170      * the given path.
 171      */
 172     void slotDirWatchDirty(const QString& path);
 173
 174 private:
 175     /**
 176      * Updates the roles for the given item ranges. The roles for the currently
 177      * visible items will get updated first.
 178      */
 179     void startUpdating(const KItemRangeList& itemRanges);
 180
 181     /**
 182      * Creates previews for the items starting from the first item of the
 183      * given list.
 184      * @see slotGotPreview()
 185      * @see slotPreviewFailed()
 186      * @see slotPreviewJobFinished()
 187      */
 188     void startPreviewJob(const KFileItemList& items);
 189
 190     bool hasPendingRoles() const;
 191     void resolvePendingRoles();
 192     void resetPendingRoles();
 193     void sortAndResolveAllRoles();
 194     void sortAndResolvePendingRoles();
 195     void applySortProgressToModel();
 196
 197     /**
 198      * Updates m_sortProgress to be 0 if the sort-role
 199      * needs to get resolved asynchronously and hence a
 200      * progress is required. Otherwise m_sortProgress
 201      * will be set to -1 which means that no progress
 202      * will be provided.
 203      */
 204     void updateSortProgress();
 205
 206     /**
 207      * @return True, if at least one item from the model
 208      *         has an unknown MIME-type.
 209      */
 210     bool hasUnknownMimeTypes() const;
 211
 212     enum ResolveHint {
 213         ResolveFast,
 214         ResolveAll
 215     };
 216     bool applyResolvedRoles(const KFileItem& item, ResolveHint hint);
 217     QHash<QByteArray, QVariant> rolesData(const KFileItem& item) const;
 218
 219     KFileItemList sortedItems(const QSet<KFileItem>& items) const;
 220
 221     /**
 222      * @return The number of items of the path \a path.
 223      */
 224     int subItemsCount(const QString& path) const;
 225
 226     /**
 227      * Must be invoked if a property has been changed that affects
 228      * the look of the preview. Takes care to update all previews.
 229      */
 230     void updateAllPreviews();
 231
 232 private:
 233     // Property for setPaused()/isPaused().
 234     bool m_paused;
 235
 236     // Property changes during pausing must be remembered to be able
 237     // to react when unpausing again:
 238     bool m_previewChangedDuringPausing;
 239     bool m_iconSizeChangedDuringPausing;
 240     bool m_rolesChangedDuringPausing;
 241
 242     // Property for setPreviewsShown()/previewsShown().
 243     bool m_previewShown;
 244
 245     // Property for setEnlargeSmallPreviews()/enlargeSmallPreviews()
 246     bool m_enlargeSmallPreviews;
 247
 248     // True if the role "iconPixmap" should be cleared when resolving the next
 249     // role with resolveRole(). Is necessary if the preview gets disabled
 250     // during the roles-updater has been paused by setPaused().
 251     bool m_clearPreviews;
 252
 253     int m_sortingProgress;
 254
 255     KFileItemModel* m_model;
 256     QSize m_iconSize;
 257     int m_firstVisibleIndex;
 258     int m_lastVisibleIndex;
 259     int m_maximumVisibleItems;
 260     QSet<QByteArray> m_roles;
 261     QSet<QByteArray> m_resolvableRoles;
 262     QStringList m_enabledPlugins;
 263
 264     QSet<KFileItem> m_pendingVisibleItems;
 265     QSet<KFileItem> m_pendingInvisibleItems;
 266     QList<KJob*> m_previewJobs;
 267
 268     // When downloading or copying large files, the slot slotItemsChanged()
 269     // will be called periodically within a quite short delay. To prevent
 270     // a high CPU-load by generating e.g. previews for each notification, the update
 271     // will be postponed until no file change has been done within a longer period
 272     // of time.
 273     QTimer* m_changedItemsTimer;
 274     QSet<KFileItem> m_changedItems;
 275
 276     KDirWatch* m_dirWatcher;
 277     mutable QSet<QString> m_watchedDirs; // Required as sadly KDirWatch does not offer a getter method
 278                                          // to get all watched directories.
 279 #ifdef HAVE_NEPOMUK
 280     Nepomuk2::ResourceWatcher* m_nepomukResourceWatcher;
 281     mutable QHash<QUrl, KUrl> m_nepomukUriItems;
 282 #endif
 283 };
 284
 285 #endif
 286
 287