<?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 4.6: edge.cpp Example File (graphicsview/elasticnodes/edge.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://qt.nokia.com/"><img src="images/qt-logo.png" align="left" 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="functions.html"><font color="#004faf">All Functions</font></a> · <a href="overviews.html"><font color="#004faf">Overviews</font></a></td></tr></table><h1 class="title">edge.cpp Example File<br /><span class="small-subtitle">graphicsview/elasticnodes/edge.cpp</span> </h1> <pre><span class="comment"> /**************************************************************************** ** ** Copyright (C) 2010 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. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial Usage ** Licensees holding valid Qt Commercial licenses may use this file in ** accordance with the Qt Commercial License Agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and Nokia. ** ** 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. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** $QT_END_LICENSE$ ** ****************************************************************************/</span> #include <QPainter> #include "edge.h" #include "node.h" #include <math.h> static const double Pi = 3.14159265358979323846264338327950288419717; static double TwoPi = 2.0 * Pi; Edge::Edge(Node *sourceNode, Node *destNode) : arrowSize(10) { setAcceptedMouseButtons(0); source = sourceNode; dest = destNode; source->addEdge(this); dest->addEdge(this); adjust(); } Edge::~Edge() { } Node *Edge::sourceNode() const { return source; } void Edge::setSourceNode(Node *node) { source = node; adjust(); } Node *Edge::destNode() const { return dest; } void Edge::setDestNode(Node *node) { dest = node; adjust(); } void Edge::adjust() { if (!source || !dest) return; QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0)); qreal length = line.length(); prepareGeometryChange(); if (length > qreal(20.)) { QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length); sourcePoint = line.p1() + edgeOffset; destPoint = line.p2() - edgeOffset; } else { sourcePoint = destPoint = line.p1(); } } QRectF Edge::boundingRect() const { if (!source || !dest) return QRectF(); qreal penWidth = 1; qreal extra = (penWidth + arrowSize) / 2.0; return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(), destPoint.y() - sourcePoint.y())) .normalized() .adjusted(-extra, -extra, extra, extra); } void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) { if (!source || !dest) return; QLineF line(sourcePoint, destPoint); if (qFuzzyCompare(line.length(), qreal(0.))) return; <span class="comment">// Draw the line itself</span> painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin)); painter->drawLine(line); <span class="comment">// Draw the arrows</span> double angle = ::acos(line.dx() / line.length()); if (line.dy() >= 0) angle = TwoPi - angle; QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize, cos(angle + Pi / 3) * arrowSize); QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize, cos(angle + Pi - Pi / 3) * arrowSize); QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize, cos(angle - Pi / 3) * arrowSize); QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize, cos(angle - Pi + Pi / 3) * arrowSize); painter->setBrush(Qt::black); painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2); painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2); }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="40%" align="left">Copyright © 2010 Nokia Corporation and/or its subsidiary(-ies)</td> <td width="20%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="40%" align="right"><div align="right">Qt 4.6.3</div></td> </tr></table></div></address></body> </html>