ImageManager/Manager.h

   1 /* Copyright (C) 2003-2006 Jesper K. Pedersen <blackie@kde.org>
   2
   3    This program is free software; you can redistribute it and/or
   4    modify it under the terms of the GNU General Public
   5    License as published by the Free Software Foundation; either
   6    version 2 of the License, or (at your option) any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11    General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program; see the file COPYING.  If not, write to
  15    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  16    Boston, MA 02110-1301, USA.
  17 */
  18
  19 #ifndef IMAGEMANAGER_H
  20 #define IMAGEMANAGER_H
  21 #include <qwaitcondition.h>
  22 #include <QList>
  23 #include <qevent.h>
  24 #include <qmutex.h>
  25 #include <qimage.h>
  26 #include "RequestQueue.h"
  27 #include "StopAction.h"
  28
  29 class ImageRequest;
  30 namespace ImageManager
  31 {
  32
  33 class ImageClient;
  34 class ImageLoader;
  35  class ThumbnailStorage;
  36
  37 class ImageEvent :public QEvent {
  38 public:
  39     ImageEvent( ImageRequest* request, const QImage& image );
  40     ImageRequest* loadInfo();
  41     QImage image();
  42
  43 private:
  44     ImageRequest* _request;
  45     QImage _image;
  46 };
  47
  48 // This class needs to inherit QObject to be capable of receiving events.
  49 class Manager :public QObject {
  50     Q_OBJECT
  51
  52 public:
  53     static Manager* instance();
  54
  55     // Request to load an image. The Manager takes over the ownership of
  56     // the request.
  57     void load( ImageRequest* request );
  58
  59     // Stop loading all images requested by the given client.
  60     void stop( ImageClient*, StopAction action = StopAll );
  61
  62     // Remove the thumbnail for a given file.
  63     void removeThumbnail( const QString& imageFile );
  64
  65     // Return if downscaled thumbnails exist for the given image file.
  66     bool thumbnailsExist( const QString& imageFile );
  67
  68 protected:
  69     virtual void customEvent( QEvent* ev );
  70     void loadVideo( ImageRequest* );
  71     void loadImage( ImageRequest* );
  72
  73 private:
  74     friend class ImageLoader;  // may call 'next()'
  75     Manager();
  76     void init();
  77
  78     ImageRequest* next();
  79
  80     static Manager* _instance;
  81
  82     RequestQueue _loadList;
  83     QWaitCondition _sleepers;
  84     QMutex _lock;
  85     QSet<ImageRequest*> _currentLoading;
  86     ThumbnailStorage* const _thumbnailStorage;
  87 };
  88
  89 }
  90
  91 #endif /* IMAGEMANAGER_H */
  92