/******************************************************************************** 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 <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; // Draw the line itself painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin)); painter->drawLine(line); // Draw the arrows 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); }