view widgets/LEDButton.cpp @ 349:369a197737c7

* Various fixes to object lifetime management, particularly in the spectrum
  layer and for notification of main model deletion.
  The main purpose of this is to improve the behaviour of the spectrum, but I
  think it may also help with #1840922 Various crashes in Layer Summary window.

/* -*- 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.
*/

/*
    This is a modified version of a source file from the KDE
    libraries.  Copyright (c) 1998-2004 Jörg Habenicht, Richard J
    Moore, Chris Cannam and others, distributed under the GNU Lesser
    General Public License.

    Ported to Qt4 by Chris Cannam.
*/


#include "LEDButton.h"

#include <QPainter>
#include <QImage>
#include <QColor>
#include <QMouseEvent>

#include <iostream>


class LEDButton::LEDButtonPrivate
{
    friend class LEDButton;

    int dark_factor;
    QColor offcolor;
    QPixmap *off_map;
    QPixmap *on_map;
};


LEDButton::LEDButton(QWidget *parent) :
    QWidget(parent),
    led_state(true)
{
    QColor col(Qt::green);
    d = new LEDButton::LEDButtonPrivate;
    d->dark_factor = 300;
    d->offcolor = col.dark(300);
    d->off_map = 0;
    d->on_map = 0;
    
    setColor(col);
}


LEDButton::LEDButton(const QColor& col, QWidget *parent) :
    QWidget(parent),
    led_state(true)
{
    d = new LEDButton::LEDButtonPrivate;
    d->dark_factor = 300;
    d->offcolor = col.dark(300);
    d->off_map = 0;
    d->on_map = 0;

    setColor(col);
}

LEDButton::LEDButton(const QColor& col, bool state, QWidget *parent) :
    QWidget(parent),
    led_state(state)
{
    d = new LEDButton::LEDButtonPrivate;
    d->dark_factor = 300;
    d->offcolor = col.dark(300);
    d->off_map = 0;
    d->on_map = 0;

    setColor(col);
}

LEDButton::~LEDButton()
{
    delete d->off_map;
    delete d->on_map;
    delete d;
}

void
LEDButton::mousePressEvent(QMouseEvent *e)
{
    std::cerr << "LEDButton(" << this << ")::mousePressEvent" << std::endl;

    if (e->buttons() & Qt::LeftButton) {
	toggle();
	bool newState = state();
	std::cerr << "emitting new state " << newState << std::endl;
	emit stateChanged(newState);
    }
}

void
LEDButton::enterEvent(QEvent *)
{
    emit mouseEntered();
}

void
LEDButton::leaveEvent(QEvent *)
{
    emit mouseLeft();
}

void
LEDButton::paintEvent(QPaintEvent *)
{
    QPainter paint;
    QColor color;
    QBrush brush;
    QPen pen;
		
    // First of all we want to know what area should be updated
    // Initialize coordinates, width, and height of the LED
    int	width = this->width();

    // Make sure the LED is round!
    if (width > this->height())
	width = this->height();
    width -= 2; // leave one pixel border
    if (width < 0) 
	width = 0;

    QPixmap *tmpMap = 0;

    if (led_state) {
	if (d->on_map) {
	    paint.begin(this);
	    paint.drawPixmap(0, 0, *d->on_map);
	    paint.end();
	    return;
	}
    } else {
	if (d->off_map) {
	    paint.begin(this);
	    paint.drawPixmap(0, 0, *d->off_map);
	    paint.end();
	    return;
	}
    }

    int scale = 1;
    width *= scale;

    tmpMap = new QPixmap(width, width);
    tmpMap->fill(palette().background().color());
    paint.begin(tmpMap);

    paint.setRenderHint(QPainter::Antialiasing, true);

    // Set the color of the LED according to given parameters
    color = (led_state) ? led_color : d->offcolor;

    // Set the brush to SolidPattern, this fills the entire area
    // of the ellipse which is drawn first
    brush.setStyle(Qt::SolidPattern);
    brush.setColor(color);
    paint.setBrush(brush);

    // Draws a "flat" LED with the given color:
    paint.drawEllipse( scale, scale, width - scale*2, width - scale*2 );

    // Draw the bright light spot of the LED now, using modified "old"
    // painter routine taken from KDEUI´s LEDButton widget:

    // Setting the new width of the pen is essential to avoid "pixelized"
    // shadow like it can be observed with the old LED code
    pen.setWidth( 2 * scale );

    // shrink the light on the LED to a size about 2/3 of the complete LED
    int pos = width/5 + 1;
    int light_width = width;
    light_width *= 2;
    light_width /= 3;
	
    // Calculate the LED´s "light factor":
    int light_quote = (130*2/(light_width?light_width:1))+100;

    // Now draw the bright spot on the LED:
    while (light_width) {
	color = color.light( light_quote );                      // make color lighter
	pen.setColor( color );                                   // set color as pen color
	paint.setPen( pen );                                     // select the pen for drawing
	paint.drawEllipse( pos, pos, light_width, light_width ); // draw the ellipse (circle)
	light_width--;
	if (!light_width)
	    break;
	paint.drawEllipse( pos, pos, light_width, light_width );
	light_width--;
	if (!light_width)
	    break;
	paint.drawEllipse( pos, pos, light_width, light_width );
	pos++; light_width--;
    }

    // Drawing of bright spot finished, now draw a thin border
    // around the LED which resembles a shadow with light coming
    // from the upper left.

//    pen.setWidth( 2 * scale + 1 ); // ### shouldn't this value be smaller for smaller LEDs?
    pen.setWidth(2 * scale);
    brush.setStyle(Qt::NoBrush);
    paint.setBrush(brush); // This avoids filling of the ellipse

    // Set the initial color value to colorGroup().light() (bright) and start
    // drawing the shadow border at 45° (45*16 = 720).

    int angle = -720;
    color = palette().light().color();
    
    for (int arc = 120; arc < 2880; arc += 240) {
	pen.setColor(color);
	paint.setPen(pen);
	int w = width - pen.width()/2 - scale + 1;
	paint.drawArc(pen.width()/2 + 1, pen.width()/2 + 1, w - 2, w - 2, angle + arc, 240);
	paint.drawArc(pen.width()/2 + 1, pen.width()/2 + 1, w - 2, w - 2, angle - arc, 240);
	color = color.dark(110); //FIXME: this should somehow use the contrast value
    }	// end for ( angle = 720; angle < 6480; angle += 160 )

    paint.end();
    //
    // painting done

    QPixmap *&dest = led_state ? d->on_map : d->off_map;

    if (scale > 1) {

	QImage i = tmpMap->toImage();
	width /= scale;
	delete tmpMap;
	dest = new QPixmap(QPixmap::fromImage
			   (i.scaled(width, width, 
				     Qt::KeepAspectRatio,
				     Qt::SmoothTransformation)));

    } else {

	dest = tmpMap;
    }

    paint.begin(this);
    paint.drawPixmap(0, 0, *dest);
    paint.end();
}

bool
LEDButton::state() const
{
    return led_state;
}

QColor
LEDButton::color() const
{
    return led_color;
}

void
LEDButton::setState( bool state )
{
    if (led_state != state)
    {
	led_state = state;
	update();
    }
}

void
LEDButton::toggleState()
{
    led_state = (led_state == true) ? false : true;
    // setColor(led_color);
    update();
}

void
LEDButton::setColor(const QColor& col)
{
    if(led_color!=col) {
	led_color = col;
	d->offcolor = col.dark(d->dark_factor);
	delete d->on_map;
	d->on_map = 0;
	delete d->off_map;
	d->off_map = 0;
	update();
    }
}

void
LEDButton::setDarkFactor(int darkfactor)
{
    if (d->dark_factor != darkfactor) {
	d->dark_factor = darkfactor;
	d->offcolor = led_color.dark(darkfactor);
	update();
    }
}

int
LEDButton::darkFactor() const
{
    return d->dark_factor;
}

void
LEDButton::toggle()
{
    toggleState();
}

void
LEDButton::on()
{
    setState(true);
}

void
LEDButton::off()
{
    setState(false);
}

QSize
LEDButton::sizeHint() const
{
    return QSize(17, 17);
}

QSize
LEDButton::minimumSizeHint() const
{
    return QSize(17, 17);
}