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     void slotGotPreview(const KFileItem& item, const QPixmap& pixmap);
 111     void slotPreviewFailed(const KFileItem& item);
 112
 113     /**
 114      * Is invoked when the preview job has been finished and
 115      * removes the job from the m_previewJobs list.
 116      */
 117     void slotPreviewJobFinished(KJob* job);
 118
 119     void resolvePendingRoles();
 120     void resolveNextPendingRoles();
 121
 122 private:
 123     void startPreviewJob(const KFileItemList& items);
 124
 125     bool hasPendingRoles() const;
 126     void resetPendingRoles();
 127     void triggerPendingRolesResolving(int count);
 128     void sortAndResolveAllRoles();
 129     void sortAndResolvePendingRoles();
 130
 131     enum ResolveHint {
 132         ResolveFast,
 133         ResolveAll
 134     };
 135     bool applyResolvedRoles(const KFileItem& item, ResolveHint hint);
 136     QHash<QByteArray, QVariant> rolesData(const KFileItem& item) const;
 137
 138     KFileItemList sortedItems(const QSet<KFileItem>& items) const;
 139
 140     static int subDirectoriesCount(const QString& path);
 141
 142 private:
 143     // Property for setPaused()/isPaused().
 144     bool m_paused;
 145
 146     // Property changes during pausing must be remembered to be able
 147     // to react when unpausing again:
 148     bool m_previewChangedDuringPausing;
 149     bool m_iconSizeChangedDuringPausing;
 150     bool m_rolesChangedDuringPausing;
 151
 152     // Property for setPreviewShown()/previewShown().
 153     bool m_previewShown;
 154
 155     // True if the role "iconPixmap" should be cleared when resolving the next
 156     // role with resolveRole(). Is necessary if the preview gets disabled
 157     // during the roles-updater has been paused by setPaused().
 158     bool m_clearPreviews;
 159
 160     KFileItemModel* m_model;
 161     QSize m_iconSize;
 162     int m_firstVisibleIndex;
 163     int m_lastVisibleIndex;
 164     QSet<QByteArray> m_roles;
 165     QStringList m_enabledPlugins;
 166
 167     QSet<KFileItem> m_pendingVisibleItems;
 168     QSet<KFileItem> m_pendingInvisibleItems;
 169     QList<KJob*> m_previewJobs;
 170
 171     QTimer* m_resolvePendingRolesTimer;
 172 };
 173
 174 #endif
 175
 176