view widgets/AudioDial.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.
*/

/**
 * A rotary dial widget.
 *
 * Based on an original design by Thorsten Wilms.
 *
 * Implemented as a widget for the Rosegarden MIDI and audio sequencer
 * and notation editor by Chris Cannam.
 *
 * Extracted into a standalone Qt3 widget by Pedro Lopez-Cabanillas
 * and adapted for use in QSynth.
 * 
 * Ported to Qt4 by Chris Cannam.
 *
 * This file copyright 2003-2005 Chris Cannam, copyright 2005 Pedro
 * Lopez-Cabanillas.
 *
 * 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.
 */

#include "AudioDial.h"

#include <cmath>
#include <iostream>

#include <QTimer>
#include <QPainter>
#include <QPixmap>
#include <QImage>
#include <QColormap>
#include <QMouseEvent>
#include <QPaintEvent>

using std::endl;
using std::cerr;


//!!! Pedro updated his version to use my up/down response code from RG -- need to grab that code in preference to this version from Rui


//-------------------------------------------------------------------------
// AudioDial - Instance knob widget class.
//

#define AUDIO_DIAL_MIN (0.25 * M_PI)
#define AUDIO_DIAL_MAX (1.75 * M_PI)
#define AUDIO_DIAL_RANGE (AUDIO_DIAL_MAX - AUDIO_DIAL_MIN)


// Constructor.
AudioDial::AudioDial(QWidget *parent) :
    QDial(parent),
    m_knobColor(Qt::black), m_meterColor(Qt::white)
{
    m_mouseDial = false;
    m_mousePressed = false;
}


// Destructor.
AudioDial::~AudioDial (void)
{
}


void AudioDial::paintEvent(QPaintEvent *)
{
    QPainter paint;

    float angle = AUDIO_DIAL_MIN // offset
	+ (AUDIO_DIAL_RANGE *
	   (float(QDial::value() - QDial::minimum()) /
	    (float(QDial::maximum() - QDial::minimum()))));
    int degrees = int(angle * 180.0 / M_PI);

    int ns = notchSize();
    int numTicks = 1 + (maximum() + ns - minimum()) / ns;
	
    QColor knobColor(m_knobColor);
    if (knobColor == Qt::black)
	knobColor = palette().mid().color();

    QColor meterColor(m_meterColor);
    if (!isEnabled())
	meterColor = palette().mid().color();
    else if (m_meterColor == Qt::white)
	meterColor = palette().highlight().color();

    int m_size = width() < height() ? width() : height();
    int scale = 1;
    int width = m_size - 2*scale, height = m_size - 2*scale;

    paint.begin(this);
    paint.setRenderHint(QPainter::Antialiasing, true);
    paint.translate(1, 1);

    QPen pen;
    QColor c;

    // Knob body and face...

    c = knobColor;
    pen.setColor(knobColor);
    pen.setWidth(scale * 2);
    pen.setCapStyle(Qt::FlatCap);
	
    paint.setPen(pen);
    paint.setBrush(c);

    int indent = (int)(width * 0.15 + 1);

    paint.drawEllipse(indent-1, indent-1, width-2*indent, width-2*indent);

    pen.setWidth(3 * scale);
    int pos = indent-1 + (width-2*indent) / 20;
    int darkWidth = (width-2*indent) * 3 / 4;
    while (darkWidth) {
	c = c.light(102);
	pen.setColor(c);
	paint.setPen(pen);
	paint.drawEllipse(pos, pos, darkWidth, darkWidth);
	if (!--darkWidth) break;
	paint.drawEllipse(pos, pos, darkWidth, darkWidth);
	if (!--darkWidth) break;
	paint.drawEllipse(pos, pos, darkWidth, darkWidth);
	++pos; --darkWidth;
    }

    // Tick notches...

    if ( true/* notchesVisible() */) {
//	std::cerr << "Notches visible" << std::endl;
	pen.setColor(palette().dark().color());
	pen.setWidth(scale);
	paint.setPen(pen);
	for (int i = 0; i < numTicks; ++i) {
	    int div = numTicks;
	    if (div > 1) --div;
	    drawTick(paint, AUDIO_DIAL_MIN + (AUDIO_DIAL_MAX - AUDIO_DIAL_MIN) * i / div,
		     width, true);
	}
    }

    // The bright metering bit...

    c = meterColor;
    pen.setColor(c);
    pen.setWidth(indent);
    paint.setPen(pen);

//    std::cerr << "degrees " << degrees << ", gives us " << -(degrees - 45) * 16 << std::endl;

    int arcLen = -(degrees - 45) * 16;
    if (arcLen == 0) arcLen = -16;

    paint.drawArc(indent/2, indent/2,
		  width-indent, width-indent, (180 + 45) * 16, arcLen);

    paint.setBrush(Qt::NoBrush);

    // Shadowing...

    pen.setWidth(scale);
    paint.setPen(pen);

    // Knob shadow...

    int shadowAngle = -720;
    c = knobColor.dark();
    for (int arc = 120; arc < 2880; arc += 240) {
	pen.setColor(c);
	paint.setPen(pen);
	paint.drawArc(indent, indent,
		      width-2*indent, width-2*indent, shadowAngle + arc, 240);
	paint.drawArc(indent, indent,
		      width-2*indent, width-2*indent, shadowAngle - arc, 240);
	c = c.light(110);
    }

    // Scale shadow...

    shadowAngle = 2160;
    c = palette().dark().color();
    for (int arc = 120; arc < 2880; arc += 240) {
	pen.setColor(c);
	paint.setPen(pen);
	paint.drawArc(scale/2, scale/2,
		      width-scale, width-scale, shadowAngle + arc, 240);
	paint.drawArc(scale/2, scale/2,
		      width-scale, width-scale, shadowAngle - arc, 240);
	c = c.light(108);
    }

    // Undraw the bottom part...

    pen.setColor(palette().background().color());
    pen.setWidth(scale * 4);
    paint.setPen(pen);
    paint.drawArc(scale/2, scale/2,
		  width-scale, width-scale, -45 * 16, -92 * 16);

    // Scale ends...

    pen.setColor(palette().dark().color());
    pen.setWidth(scale);
    paint.setPen(pen);
    for (int i = 0; i < numTicks; ++i) {
	if (i != 0 && i != numTicks - 1) continue;
	int div = numTicks;
	if (div > 1) --div;
	drawTick(paint, AUDIO_DIAL_MIN + (AUDIO_DIAL_MAX - AUDIO_DIAL_MIN) * i / div,
		 width, false);
    }

    // Pointer notch...

    float hyp = float(width) / 2.0;
    float len = hyp - indent;
    --len;

    float x0 = hyp;
    float y0 = hyp;

    float x = hyp - len * sin(angle);
    float y = hyp + len * cos(angle);

    c = palette().dark().color();
    pen.setColor(isEnabled() ? c.dark(130) : c);
    pen.setWidth(scale * 2);
    paint.setPen(pen);
    paint.drawLine(int(x0), int(y0), int(x), int(y));

    paint.end();
}


void AudioDial::drawTick(QPainter &paint,
			 float angle, int size, bool internal)
{
    float hyp = float(size) / 2.0;
    float x0 = hyp - (hyp - 1) * sin(angle);
    float y0 = hyp + (hyp - 1) * cos(angle);

//    cerr << "drawTick: angle " << angle << ", size " << size << ", internal " << internal << endl;
    
    if (internal) {

	float len = hyp / 4;
	float x1 = hyp - (hyp - len) * sin(angle);
	float y1 = hyp + (hyp - len) * cos(angle);
		
	paint.drawLine(int(x0), int(y0), int(x1), int(y1));

    } else {

	float len = hyp / 4;
	float x1 = hyp - (hyp + len) * sin(angle);
	float y1 = hyp + (hyp + len) * cos(angle);

	paint.drawLine(int(x0), int(y0), int(x1), int(y1));
    }
}


void AudioDial::setKnobColor(const QColor& color)
{
    m_knobColor = color;
    update();
}


void AudioDial::setMeterColor(const QColor& color)
{
    m_meterColor = color;
    update();
}


void AudioDial::setMouseDial(bool mouseDial)
{
    m_mouseDial = mouseDial;
}


// Alternate mouse behavior event handlers.
void AudioDial::mousePressEvent(QMouseEvent *mouseEvent)
{
    if (m_mouseDial) {
	QDial::mousePressEvent(mouseEvent);
    } else if (mouseEvent->button() == Qt::LeftButton) {
	m_mousePressed = true;
	m_posMouse = mouseEvent->pos();
    }
}


void AudioDial::mouseMoveEvent(QMouseEvent *mouseEvent)
{
    if (m_mouseDial) {
	QDial::mouseMoveEvent(mouseEvent);
    } else if (m_mousePressed) {
	const QPoint& posMouse = mouseEvent->pos();
	int v = QDial::value()
	    + (posMouse.x() - m_posMouse.x())
	    + (m_posMouse.y() - posMouse.y());
	if (v > QDial::maximum())
	    v = QDial::maximum();
	else
	    if (v < QDial::minimum())
		v = QDial::minimum();
	m_posMouse = posMouse;
	QDial::setValue(v);
    }
}


void AudioDial::mouseReleaseEvent(QMouseEvent *mouseEvent)
{
    if (m_mouseDial) {
	QDial::mouseReleaseEvent(mouseEvent);
    } else if (m_mousePressed) {
	m_mousePressed = false;
    }
}

#ifdef INCLUDE_MOCFILES
#include "AudioDial.moc.cpp"
#endif