<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Qt 4.2: circlewidget.cpp Example File (painting/concentriccircles/circlewidget.cpp)</title> <link href="classic.css" rel="stylesheet" type="text/css" /> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td align="left" valign="top" width="32"><a href="http://www.trolltech.com/products/qt"><img src="images/qt-logo.png" align="left" width="32" height="32" border="0" /></a></td> <td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> · <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a> · <a href="functions.html"><font color="#004faf">Functions</font></a></td> <td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">circlewidget.cpp Example File<br /><sup><sup>painting/concentriccircles/circlewidget.cpp</sup></sup></h1> <pre> /**************************************************************************** ** ** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved. ** ** This file is part of the example classes of the Qt Toolkit. ** ** This file may be used under the terms of the GNU General Public ** License version 2.0 as published by the Free Software Foundation ** and appearing in the file LICENSE.GPL included in the packaging of ** this file. Please review the following information to ensure GNU ** General Public Licensing requirements will be met: ** http:<span class="comment">//www.trolltech.com/products/qt/opensource.html</span> ** ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http:<span class="comment">//www.trolltech.com/products/qt/licensing.html or contact the</span> ** sales department at sales@trolltech.com. ** ** 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)); } } } }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="30%">Copyright © 2006 <a href="trolltech.html">Trolltech</a></td> <td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="30%" align="right"><div align="right">Qt 4.2.1</div></td> </tr></table></div></address></body> </html>