/****************************************************************************
**
** Copyright (C) 2005-2005 Trolltech AS. All rights reserved.
**
** This file is part of the example classes of the Qt Toolkit.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
** information about Qt Commercial License Agreements.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include <QtGui>

#include "circlewidget.h"

#include <stdlib.h>

CircleWidget::CircleWidget(QWidget *parent)
    : QWidget(parent)
{
    floatBased = false;
    antialiased = false;
    frameNo = 0;

    setBackgroundRole(QPalette::Base);
    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
}

void CircleWidget::setFloatBased(bool floatBased)
{
    this->floatBased = floatBased;
    update();
}

void CircleWidget::setAntialiased(bool antialiased)
{
    this->antialiased = antialiased;
    update();
}

QSize CircleWidget::minimumSizeHint() const
{
    return QSize(50, 50);
}

QSize CircleWidget::sizeHint() const
{
    return QSize(180, 180);
}

void CircleWidget::nextAnimationFrame()
{
    ++frameNo;
    update();
}

void CircleWidget::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, antialiased);
    painter.translate(width() / 2, height() / 2);

    for (int diameter = 0; diameter < 256; diameter += 9) {
        int delta = abs((frameNo % 128) - diameter / 2);
        int alpha = 255 - (delta * delta) / 4 - diameter;
        if (alpha > 0) {
            painter.setPen(QPen(QColor(0, diameter / 2, 127, alpha), 3));

            if (floatBased) {
                painter.drawEllipse(QRectF(-diameter / 2.0, -diameter / 2.0,
                                           diameter, diameter));
            } else {
                painter.drawEllipse(QRect(-diameter / 2, -diameter / 2,
                                          diameter, diameter));
            }
        }
    }
}
