File indexing completed on 2024-05-19 04:49:50

 /****************************************************************************************
  * Copyright (c) 2007 Ian Monroe <ian@monroe.nu>                                        *
  * Copyright (c) 2008 Soren Harward <stharward@gmail.com>                               *
  * Copyright (c) 2009 Téo Mrnjavac <teo@kde.org>                                        *
  *                                                                                      *
  * This program is free software; you can redistribute it and/or modify it under        *
  * the terms of the GNU General Public License as published by the Free Software        *
  * Foundation; either version 2 of the License, or (at your option) version 3 or        *
  * any later version accepted by the membership of KDE e.V. (or its successor approved  *
  * by the membership of KDE e.V.), which shall act as a proxy defined in Section 14 of  *
  * version 3 of the license.                                                            *
  *                                                                                      *
  * This program is distributed in the hope that it will be useful, but WITHOUT ANY      *
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A      *
  * PARTICULAR PURPOSE. See the GNU General Public License for more details.             *
  *                                                                                      *
  * You should have received a copy of the GNU General Public License along with         *
  * this program.  If not, see <http://www.gnu.org/licenses/>.                           *
  ****************************************************************************************/
 
 #ifndef TRACKNAVIGATOR_H
 #define TRACKNAVIGATOR_H
 
 #include "playlist/proxymodels/AbstractModel.h"
 
 #include <QObject>
 #include <QQueue>
 
 namespace Playlist
 {
     typedef QList<quint64> ItemList; // A convenient typedef!
 
     /**
      * An abstract class which defines what should be done after a track
      * finishes playing. The Playlist::Model will have an object of the
      * currently active strategy. It is the "strategy" pattern from the Design
      * Patterns book. In Amarok 1.x, the Playlist became very confusing due to
      * random mode and dynamic playlists requiring complicated nested if
      * statements. This should prevent that.
      */
     class TrackNavigator : public QObject
     {
         Q_OBJECT
 
         public:
             TrackNavigator();
             ~TrackNavigator() override { }
 
             /**
              * what is the next track at this moment. It could change before the
              * track really plays (you need to catch playlist changes); does NOT
              * affect the navigators queue.
              */
             virtual quint64 likelyNextTrack() = 0;
 
             /**
              * what is the last track at this moment. It could change before the
              * track really plays (you need to catch playlist changes); does NOT
              * affect the navigators queue.
              */
             virtual quint64 likelyLastTrack() = 0;
 
             /**
              * The engine will finish the current track in a couple of seconds,
              * and would like to know what the next track should be.
              */
             virtual quint64 requestNextTrack() = 0;
 
             /**
              * The user triggers the next-track action.
              */
             virtual quint64 requestUserNextTrack() = 0;
 
             /**
              * The user triggers the previous-track action.
              */
             virtual quint64 requestLastTrack() = 0;
 
             /**
              * Find the position of the id in the queue
              * @return the position, or -1 if non in queue
              */
             int queuePosition( const quint64 id ) const;
 
             /**
              * Getter for the internal queue.
              * @return the tracks queued.
              */
             QQueue<quint64> queue();
 
         public Q_SLOTS:
             /**
              * Queues the specified id and schedules it to be played.
              */
             virtual void queueIds( const QList<quint64> &ids );
 
             /**
              * Dequeue the specified id from the queue list
              */
             virtual void dequeueId( const quint64 id );
 
             /**
              * Play the track one position earlier.
              */
             bool queueMoveUp( const quint64 id );
 
             /**
              * Play the track one position later.
              */
             bool queueMoveDown( const quint64 id );
 
         private Q_SLOTS:
             void slotModelReset();
             void slotRowsAboutToBeRemoved( const QModelIndex &parent, int start, int end );
 
         protected:
             /**
              * Choose the most reasonable fallback item in case a navigator wants to play
              * something, but doesn't have a good choice itself.
              */
             quint64 bestFallbackItem();
 
             // Holds the list of tracks to be played next. General
             // workflow should dictate that the TrackAdvancer should
             // respect the queue list as an override to what the Advancer
             // implementation would normally return as the next track.
             // TODO: a history queue to allow requestLastTrack() to work
             // properly?
             // Static queue so that all navigators share the same queue
             QQueue<quint64> m_queue;
 
             AbstractModel *m_model;
     };
 }
 
 #endif