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Diffstat (limited to 'examples/graphicsview/elasticnodes/edge.cpp')
-rw-r--r-- | examples/graphicsview/elasticnodes/edge.cpp | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/examples/graphicsview/elasticnodes/edge.cpp b/examples/graphicsview/elasticnodes/edge.cpp new file mode 100644 index 0000000..4018c25 --- /dev/null +++ b/examples/graphicsview/elasticnodes/edge.cpp @@ -0,0 +1,144 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, 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 are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@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(); + QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length); + + prepareGeometryChange(); + sourcePoint = line.p1() + edgeOffset; + destPoint = line.p2() - edgeOffset; +} + +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; + + // Draw the line itself + QLineF line(sourcePoint, destPoint); + painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin)); + painter->drawLine(line); + + // Draw the arrows if there's enough room + 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); +} |