/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** No Commercial Usage ** This file contains pre-release code and may not be distributed. ** You may use this file in accordance with the terms and conditions ** contained in the Technology Preview License Agreement accompanying ** this package. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** ** ** ** ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #include #include "circlewidget.h" #include //! [0] CircleWidget::CircleWidget(QWidget *parent) : QWidget(parent) { floatBased = false; antialiased = false; frameNo = 0; setBackgroundRole(QPalette::Base); setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding); } //! [0] //! [1] void CircleWidget::setFloatBased(bool floatBased) { this->floatBased = floatBased; update(); } //! [1] //! [2] void CircleWidget::setAntialiased(bool antialiased) { this->antialiased = antialiased; update(); } //! [2] //! [3] QSize CircleWidget::minimumSizeHint() const { return QSize(50, 50); } //! [3] //! [4] QSize CircleWidget::sizeHint() const { return QSize(180, 180); } //! [4] //! [5] void CircleWidget::nextAnimationFrame() { ++frameNo; update(); } //! [5] //! [6] void CircleWidget::paintEvent(QPaintEvent *) { QPainter painter(this); painter.setRenderHint(QPainter::Antialiasing, antialiased); painter.translate(width() / 2, height() / 2); //! [6] //! [7] for (int diameter = 0; diameter < 256; diameter += 9) { int delta = abs((frameNo % 128) - diameter / 2); int alpha = 255 - (delta * delta) / 4 - diameter; //! [7] //! [8] 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)); } } } } //! [8]