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