annotate audioio/AudioCallbackPlayTarget.h @ 36:b9e76c9e631c

* Fix serious failure to reload "imported" (i.e. all non-derived non-main)
  models from .sv file
* Give a short playback duration to notes with formal duration of 0 or 1
* Show crosshairs on spectrogram even when there is another layer on top
  (if it isn't opaque)
* Always paste to the same time in the layer as the cut/copy was from, rather
  than to the playback pointer -- less flexible, but more predictable and
  less annoying.  We probably need a way to get the old behaviour if pasting
  from somewhere else in the future (e.g. from a text file), but we can't do
  that yet anyway
* Use a compound operation for dragging and resizing selections, so as to
  ensure a single undo operation works
* Use a note model as the target for feature extraction plugins that output
  variable samplerate data with more than one value per feature
* Avoid possible crashes in cut/paste if a layer proves to have no model

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    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) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef _AUDIO_CALLBACK_PLAY_TARGET_H_
#define _AUDIO_CALLBACK_PLAY_TARGET_H_

#include <QObject>

class AudioCallbackPlaySource;

class AudioCallbackPlayTarget : public QObject
{
    Q_OBJECT

public:
    AudioCallbackPlayTarget(AudioCallbackPlaySource *source);
    virtual ~AudioCallbackPlayTarget();

    virtual bool isOK() const = 0;

    float getOutputGain() const {
	return m_outputGain;
    }

public slots:
    /**
     * Set the playback gain (0.0 = silence, 1.0 = levels unmodified)
     */
    virtual void setOutputGain(float gain);

    /**
     * The main source model (providing the playback sample rate) has
     * been changed.  The target should query the source's sample
     * rate, set its output sample rate accordingly, and call back on
     * the source's setTargetSampleRate to indicate what sample rate
     * it succeeded in setting at the output.  If this differs from
     * the model rate, the source will resample.
     */
    virtual void sourceModelReplaced() = 0;

protected:
    AudioCallbackPlaySource *m_source;
    float m_outputGain;
};

#endif