150 lines
4.7 KiB
C++
150 lines
4.7 KiB
C++
/****************************************************************************
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**
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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** Contact: http://www.qt-project.org/legal
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** You may use this file under the terms of the BSD license as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
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** of its contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "edge.h"
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#include "node.h"
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#include <math.h>
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#include <QPainter>
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static const double Pi = 3.14159265358979323846264338327950288419717;
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static double TwoPi = 2.0 * Pi;
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//! [0]
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Edge::Edge(Node *sourceNode, Node *destNode)
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: arrowSize(10)
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{
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setAcceptedMouseButtons(0);
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source = sourceNode;
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dest = destNode;
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source->addEdge(this);
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dest->addEdge(this);
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adjust();
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}
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//! [0]
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//! [1]
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Node *Edge::sourceNode() const
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{
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return source;
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}
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Node *Edge::destNode() const
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{
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return dest;
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}
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//! [1]
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//! [2]
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void Edge::adjust()
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{
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if (!source || !dest)
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return;
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QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0));
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qreal length = line.length();
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prepareGeometryChange();
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if (length > qreal(20.)) {
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QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length);
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sourcePoint = line.p1() + edgeOffset;
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destPoint = line.p2() - edgeOffset;
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} else {
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sourcePoint = destPoint = line.p1();
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}
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}
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//! [2]
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//! [3]
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QRectF Edge::boundingRect() const
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{
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if (!source || !dest)
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return QRectF();
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qreal penWidth = 1;
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qreal extra = (penWidth + arrowSize) / 2.0;
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return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(),
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destPoint.y() - sourcePoint.y()))
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.normalized()
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.adjusted(-extra, -extra, extra, extra);
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}
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//! [3]
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//! [4]
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void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
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{
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if (!source || !dest)
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return;
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QLineF line(sourcePoint, destPoint);
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if (qFuzzyCompare(line.length(), qreal(0.)))
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return;
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//! [4]
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//! [5]
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// Draw the line itself
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painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
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painter->drawLine(line);
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//! [5]
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//! [6]
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// Draw the arrows
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double angle = ::acos(line.dx() / line.length());
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if (line.dy() >= 0)
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angle = TwoPi - angle;
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QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize,
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cos(angle + Pi / 3) * arrowSize);
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QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
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cos(angle + Pi - Pi / 3) * arrowSize);
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QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize,
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cos(angle - Pi / 3) * arrowSize);
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QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize,
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cos(angle - Pi + Pi / 3) * arrowSize);
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painter->setBrush(Qt::black);
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painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
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painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
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}
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//! [6]
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