src/playlist/PlaylistGraphicsItem.h

   1 /***************************************************************************
   2  * copyright            : (C) 2007 Ian Monroe <ian@monroe.nu>              *
   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 version 2        *
   6  *   as published by the Free Software Foundation.                         *
   7  ***************************************************************************/
   8
   9 #ifndef AMAROK_PLAYLISTGRAPHICSITEM_H
  10 #define AMAROK_PLAYLISTGRAPHICSITEM_H
  11
  12
  13 #include "meta.h"
  14 #include <QGraphicsItem>
  15
  16 class QFontMetricsF;
  17
  18 namespace Playlist
  19 {
  20     /**
  21      * A lazy-loading QGraphicsItem to display one track in the playlist.
  22      * If a user drags 20000 tracks into the playlist, 20000 GraphicsItem's
  23      * will be created. However only the tracks that are visible will query
  24      * the model for their information, the rest will take up very little memory
  25      * and really aren't associated with a particular track yet.
  26      * On a paint operation the GraphicsItem will be "active" by creating an ActiveItems.
  27      * Do not add any data members to GraphicsItem, you should be able to add them to
  28      * ActiveItems instead.
  29      */
  30     class GraphicsItem : public QGraphicsItem
  31     {
  32         class ActiveItems;
  33
  34         public:
  35             GraphicsItem();
  36             ~GraphicsItem();
  37             ///Be sure to read ::paint rules in-method
  38             void paint( QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget );
  39             QRectF boundingRect() const;
  40             void setupItem();
  41             static qreal height() { return s_height; }
  42             void refresh();
  43             void play();
  44
  45         protected:
  46             void dragEnterEvent( QGraphicsSceneDragDropEvent *event );
  47             void dropEvent( QGraphicsSceneDragDropEvent * event );
  48             void mouseDoubleClickEvent( QGraphicsSceneMouseEvent* event );
  49             void mousePressEvent( QGraphicsSceneMouseEvent* event );
  50             void mouseMoveEvent( QGraphicsSceneMouseEvent* event );
  51             void mouseReleaseEvent ( QGraphicsSceneMouseEvent * event );
  52
  53         private:
  54             void init( Meta::TrackPtr track );
  55             void resize( Meta::TrackPtr track, int totalWidth );
  56             int getRow() const { return int( ( mapToScene( 0.0, 0.0 ).y() ) / s_height ); }
  57
  58
  59
  60             ActiveItems* m_items;
  61             static const qreal ALBUM_WIDTH;
  62             static const qreal MARGIN;
  63             static       qreal s_height;
  64             static QFontMetricsF* s_fm;
  65     };
  66
  67 }
  68 #endif
  69