annotate widgets/Fader.cpp @ 11:2d5005f2b3d9

* Rework handling of layer properties in file I/O -- we now get the individual
  layers to load and save them rather than doing it via generic property lists
  in the base class, so as to ensure we read and write meaningful values rather
  than generic int values requiring conversion.

/* -*- c-basic-offset: 4 -*-  vi:set ts=8 sts=4 sw=4: */

/*
    A waveform viewer and audio annotation editor.
    Chris Cannam, Queen Mary University of London, 2005-2006
    
    This is experimental software.  Not for distribution.
*/

/**
 * Horizontal audio fader and meter widget.
 *
 * Based on the vertical fader and meter widget from the Hydrogen drum
 * machine.  (Any poor taste that has crept in during the
 * modifications for this application is entirely my own, however.)
 * The following copyright notice applies to code from this file, and
 * also to the files in icons/fader_*.png (also modified by me). --cc
 */

/**
 * Hydrogen
 * Copyright(c) 2002-2005 by Alex >Comix< Cominu [[e-mail]]
 *
 * http://www.hydrogen-music.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) any later version.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "Fader.h"

#include "base/AudioLevel.h"

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

Fader::Fader(QWidget *parent, bool withoutKnob) :
    QWidget(parent),
    m_withoutKnob(withoutKnob),
    m_value(1.0),
    m_peakLeft(0.0),
    m_peakRight(0.0)
{
    setMinimumSize(116, 23);
    setMaximumSize(116, 23);
    resize(116, 23);

    QString background_path = ":/icons/fader_background.png";
    bool ok = m_back.load(background_path);
    if (ok == false) {
	std::cerr << "Fader: Error loading pixmap" << std::endl;
    }

    QString leds_path = ":/icons/fader_leds.png";
    ok = m_leds.load(leds_path);
    if (ok == false) {
	std::cerr <<  "Error loading pixmap" << std::endl;
    }

    QString knob_path = ":/icons/fader_knob.png";
    ok = m_knob.load(knob_path);
    if (ok == false) {
	std::cerr <<  "Error loading pixmap" << std::endl;
    }

    QString clip_path = ":/icons/fader_knob_red.png";
    ok = m_clip.load(clip_path);
    if (ok == false) {
	std::cerr <<  "Error loading pixmap" << std::endl;
    }
}

Fader::~Fader()
{

}

void
Fader::mouseMoveEvent(QMouseEvent *ev)
{
    int x = ev->x() - 6;
    const int max_x = 116 - 12;

    int value = x;

    if (value > max_x) {
	value = max_x;
    } else if (value < 0) {
	value = 0;
    }

//    float fval = float(value) / float(max_x);
    float fval = AudioLevel::fader_to_multiplier
	(value, max_x, AudioLevel::LongFader);

    setValue(fval);
    emit valueChanged(fval);

    update();
}


void
Fader::mouseDoubleClickEvent(QMouseEvent *)
{
    setValue(1.0);
    emit valueChanged(1.0);
    update();
}

void
Fader::mousePressEvent(QMouseEvent *ev)
{
    int x = ev->x() - 6;
    const int max_x = 116 - 12;

    int value = x;

    if (value > max_x) {
	value = max_x;
    } else if (value < 0) {
	value = 0;
    }

    float fval = AudioLevel::fader_to_multiplier
	(value, max_x, AudioLevel::LongFader);

    setValue(fval);
    emit valueChanged(fval);

    update();
}


void
Fader::wheelEvent(QWheelEvent *ev)
{
    ev->accept();

    //!!! needs improvement

    if (ev->delta() > 0) {
	setValue(m_value * 1.1);
    } else {
	setValue(m_value / 1.1);
    }

    update();
    emit valueChanged(getValue());
}


void
Fader::setValue(float v)
{
    float max = AudioLevel::dB_to_multiplier(10.0);

    if (v > max) {
	v = max;
    } else if (v < 0.0) {
	v = 0.0;
    }

    if (m_value != v) {
	m_value = v;
	float db = AudioLevel::multiplier_to_dB(m_value);
	if (db <= AudioLevel::DB_FLOOR) {
	    setToolTip(tr("Level: Off"));
	} else {
	    setToolTip(tr("Level: %1%2.%3%4 dB")
		       .arg(db < 0.0 ? "-" : "")
		       .arg(abs(int(db)))
		       .arg(abs(int(db * 10.0) % 10))
		       .arg(abs(int(db * 100.0) % 10)));
	}
	update();
    }
}


float
Fader::getValue()
{
    return m_value;
}



void
Fader::setPeakLeft(float peak)
{
    if (this->m_peakLeft != peak) {
	this->m_peakLeft = peak;
	update();
    }
}


void
Fader::setPeakRight(float peak) 
{
    if (this->m_peakRight != peak) {
	this->m_peakRight = peak;
	update();
    }
}


void
Fader::paintEvent(QPaintEvent *)
{
    QPainter painter(this);

    // background
    painter.drawPixmap(rect(), m_back, QRect(0, 0, 116, 23));

    int offset_L = AudioLevel::multiplier_to_fader(m_peakLeft, 116,
						   AudioLevel::IEC268LongMeter);

    painter.drawPixmap(QRect(0, 0, offset_L, 11), m_leds,
		       QRect(0, 0, offset_L, 11));

    int offset_R = AudioLevel::multiplier_to_fader(m_peakRight, 116,
						   AudioLevel::IEC268LongMeter);

    painter.drawPixmap(QRect(0, 11, offset_R, 11), m_leds,
		       QRect(0, 11, offset_R, 11));

    if (m_withoutKnob == false) {

	static const uint knob_width = 29;
	static const uint knob_height = 9;

	int x = AudioLevel::multiplier_to_fader(m_value, 116 - knob_width,
						AudioLevel::LongFader);

	bool clipping = (m_peakLeft > 1.0 || m_peakRight > 1.0);

	painter.drawPixmap(QRect(x, 7, knob_width, knob_height),
			   clipping ? m_clip : m_knob,
			   QRect(0, 0, knob_width, knob_height));
    }
}