src/kitemviews/private/knepomukrolesprovider.h

   1 /***************************************************************************
   2  *   Copyright (C) 2012 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 KNEPOMUKROLESPROVIDER_H
  21 #define KNEPOMUKROLESPROVIDER_H
  22
  23 #include <libdolphin_export.h>
  24
  25 #include <QHash>
  26 #include <QSet>
  27 #include <QUrl>
  28
  29 namespace Nepomuk
  30 {
  31     class Resource;
  32 }
  33
  34 /**
  35  * @brief Allows accessing metadata of a file by providing KFileItemModel roles.
  36  *
  37  * Is a helper class for KFileItemModelRolesUpdater to retrieve roles that
  38  * are only accessible with Nepomuk.
  39  */
  40 class LIBDOLPHINPRIVATE_EXPORT KNepomukRolesProvider
  41 {
  42 public:
  43     static KNepomukRolesProvider& instance();
  44     virtual ~KNepomukRolesProvider();
  45
  46     /**
  47      * @return Roles that can be provided by KNepomukRolesProvider.
  48      */
  49     QSet<QByteArray> roles() const;
  50
  51     /**
  52      * @return Values for the roles \a roles that can be determined from the file
  53      *         with the URL \a url.
  54      */
  55     QHash<QByteArray, QVariant> roleValues(const Nepomuk::Resource& resource,
  56                                            const QSet<QByteArray>& roles) const;
  57
  58 protected:
  59     KNepomukRolesProvider();
  60
  61 private:
  62     /**
  63      * @return User visible string for the given tag-values.
  64      */
  65     QString tagsFromValues(const QStringList& values) const;
  66
  67     /**
  68      * @return User visible string for the EXIF-orientation property
  69      *         which can have the values 0 to 8.
  70      *         (see http://sylvana.net/jpegcrop/exif_orientation.html)
  71      */
  72     QString orientationFromValue(int value) const;
  73
  74     /**
  75      * @return Duration in the format HH::MM::SS for the value given
  76      *         in milliseconds.
  77      */
  78     QString durationFromValue(int value) const;
  79
  80 private:
  81     QSet<QByteArray> m_roles;
  82     QHash<QUrl, QByteArray> m_roleForUri;
  83
  84     friend class KNepomukRolesProviderSingleton;
  85 };
  86
  87 #endif
  88