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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "edge.h"
#include "node.h"
#include <QPainter>
#include <QtMath>
//! [0]
Edge::Edge(Node *sourceNode, Node *destNode)
: source(sourceNode), dest(destNode)
{
setAcceptedMouseButtons(Qt::NoButton);
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 = std::atan2(-line.dy(), line.dx());
QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + M_PI / 3) * arrowSize,
cos(angle + M_PI / 3) * arrowSize);
QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + M_PI - M_PI / 3) * arrowSize,
cos(angle + M_PI - M_PI / 3) * arrowSize);
QPointF destArrowP1 = destPoint + QPointF(sin(angle - M_PI / 3) * arrowSize,
cos(angle - M_PI / 3) * arrowSize);
QPointF destArrowP2 = destPoint + QPointF(sin(angle - M_PI + M_PI / 3) * arrowSize,
cos(angle - M_PI + M_PI / 3) * arrowSize);
painter->setBrush(Qt::black);
painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
}
//! [6]
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