annotate widgets/Fader.h @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 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 FADER_H
#define FADER_H

/**
 * Horizontal audio fader and meter widget.
 * Based on the vertical fader and meter widget from:
 * 
 * Hydrogen
 * Copyright(c) 2002-2005 by Alex >Comix< Cominu [[e-mail]]
 * http://www.hydrogen-music.org
 */


#include <string>
#include <iostream>

#include <QWidget>
#include <QPixmap>
#include <QMouseEvent>
#include <QWheelEvent>
#include <QPaintEvent>

#include "base/Debug.h"

class Fader : public QWidget
{
    Q_OBJECT

public:
    Fader(QWidget *parent, bool withoutKnob = false);
    ~Fader();

    void setValue(float newValue);
    float getValue();

    void setPeakLeft(float);
    float getPeakLeft() { return m_peakLeft; }

    void setPeakRight(float);
    float getPeakRight() { return m_peakRight; }

signals:
    void valueChanged(float); // 0.0 -> 1.0

    void mouseEntered();
    void mouseLeft();

protected:
    virtual void mousePressEvent(QMouseEvent *ev);
    virtual void mouseDoubleClickEvent(QMouseEvent *ev);
    virtual void mouseMoveEvent(QMouseEvent *ev);
    virtual void mouseReleaseEvent(QMouseEvent *ev);
    virtual void wheelEvent( QWheelEvent *ev );
    virtual void paintEvent(QPaintEvent *ev);
    virtual void enterEvent(QEvent *);
    virtual void leaveEvent(QEvent *);

    int getMaxX() const;

    bool m_withoutKnob;
    float m_value;
    float m_peakLeft;
    float m_peakRight;

    bool m_mousePressed;
    int m_mousePressX;
    float m_mousePressValue;

    QPixmap m_back;
    QPixmap m_leds;
    QPixmap m_knob;
    QPixmap m_clip;
};

#endif