qt5base-lts/examples/widgets/graphicsview/elasticnodes/edge.cpp
Sergio Ahumada 48e0c4df23 Update copyright year in Digia's license headers
Change-Id: Ic804938fc352291d011800d21e549c10acac66fb
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
2013-01-18 09:07:35 +01:00

150 lines
4.7 KiB
C++

/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
** of its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "edge.h"
#include "node.h"
#include <math.h>
#include <QPainter>
static const double Pi = 3.14159265358979323846264338327950288419717;
static double TwoPi = 2.0 * Pi;
//! [0]
Edge::Edge(Node *sourceNode, Node *destNode)
: arrowSize(10)
{
setAcceptedMouseButtons(0);
source = sourceNode;
dest = destNode;
source->addEdge(this);
dest->addEdge(this);
adjust();
}
//! [0]
//! [1]
Node *Edge::sourceNode() const
{
return source;
}
Node *Edge::destNode() const
{
return dest;
}
//! [1]
//! [2]
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();
}
}
//! [2]
//! [3]
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);
}
//! [3]
//! [4]
void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
{
if (!source || !dest)
return;
QLineF line(sourcePoint, destPoint);
if (qFuzzyCompare(line.length(), qreal(0.)))
return;
//! [4]
//! [5]
// Draw the line itself
painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
painter->drawLine(line);
//! [5]
//! [6]
// 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);
}
//! [6]