Chris@43: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@43: 
Chris@43: /*
Chris@43:     Sonic Visualiser
Chris@43:     An audio file viewer and annotation editor.
Chris@43:     Centre for Digital Music, Queen Mary, University of London.
Chris@43:     This file copyright 2006 Chris Cannam.
Chris@43:     
Chris@43:     This program is free software; you can redistribute it and/or
Chris@43:     modify it under the terms of the GNU General Public License as
Chris@43:     published by the Free Software Foundation; either version 2 of the
Chris@43:     License, or (at your option) any later version.  See the file
Chris@43:     COPYING included with this distribution for more information.
Chris@43: */
Chris@43: 
Chris@43: #ifndef _AUDIO_CALLBACK_PLAY_TARGET_H_
Chris@43: #define _AUDIO_CALLBACK_PLAY_TARGET_H_
Chris@43: 
Chris@43: #include <QObject>
Chris@43: 
Chris@43: class AudioCallbackPlaySource;
Chris@43: 
Chris@43: class AudioCallbackPlayTarget : public QObject
Chris@43: {
Chris@43:     Q_OBJECT
Chris@43: 
Chris@43: public:
Chris@43:     AudioCallbackPlayTarget(AudioCallbackPlaySource *source);
Chris@43:     virtual ~AudioCallbackPlayTarget();
Chris@43: 
Chris@43:     virtual bool isOK() const = 0;
Chris@43: 
Chris@70:     virtual void shutdown() = 0;
Chris@70: 
Chris@91:     virtual double getCurrentTime() const = 0;
Chris@91: 
Chris@43:     float getOutputGain() const {
Chris@43: 	return m_outputGain;
Chris@43:     }
Chris@43: 
Chris@43: public slots:
Chris@43:     /**
Chris@43:      * Set the playback gain (0.0 = silence, 1.0 = levels unmodified)
Chris@43:      */
Chris@43:     virtual void setOutputGain(float gain);
Chris@43: 
Chris@43:     /**
Chris@43:      * The main source model (providing the playback sample rate) has
Chris@43:      * been changed.  The target should query the source's sample
Chris@43:      * rate, set its output sample rate accordingly, and call back on
Chris@43:      * the source's setTargetSampleRate to indicate what sample rate
Chris@43:      * it succeeded in setting at the output.  If this differs from
Chris@43:      * the model rate, the source will resample.
Chris@43:      */
Chris@43:     virtual void sourceModelReplaced() = 0;
Chris@43: 
Chris@43: protected:
Chris@43:     AudioCallbackPlaySource *m_source;
Chris@43:     float m_outputGain;
Chris@43: };
Chris@43: 
Chris@43: #endif
Chris@43: