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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "arrow.h"
#include "diagramitem.h"
#include <QPainter>
#include <QPen>
#include <QtMath>
//! [0]
Arrow::Arrow(DiagramItem *startItem, DiagramItem *endItem, QGraphicsItem *parent)
: QGraphicsLineItem(parent), myStartItem(startItem), myEndItem(endItem)
{
setFlag(QGraphicsItem::ItemIsSelectable, true);
setPen(QPen(myColor, 2, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
}
//! [0]
//! [1]
QRectF Arrow::boundingRect() const
{
qreal extra = (pen().width() + 20) / 2.0;
return QRectF(line().p1(), QSizeF(line().p2().x() - line().p1().x(),
line().p2().y() - line().p1().y()))
.normalized()
.adjusted(-extra, -extra, extra, extra);
}
//! [1]
//! [2]
QPainterPath Arrow::shape() const
{
QPainterPath path = QGraphicsLineItem::shape();
path.addPolygon(arrowHead);
return path;
}
//! [2]
//! [3]
void Arrow::updatePosition()
{
QLineF line(mapFromItem(myStartItem, 0, 0), mapFromItem(myEndItem, 0, 0));
setLine(line);
}
//! [3]
//! [4]
void Arrow::paint(QPainter *painter, const QStyleOptionGraphicsItem *,
QWidget *)
{
if (myStartItem->collidesWithItem(myEndItem))
return;
QPen myPen = pen();
myPen.setColor(myColor);
qreal arrowSize = 20;
painter->setPen(myPen);
painter->setBrush(myColor);
//! [4] //! [5]
QLineF centerLine(myStartItem->pos(), myEndItem->pos());
QPolygonF endPolygon = myEndItem->polygon();
QPointF p1 = endPolygon.first() + myEndItem->pos();
QPointF intersectPoint;
for (int i = 1; i < endPolygon.count(); ++i) {
QPointF p2 = endPolygon.at(i) + myEndItem->pos();
QLineF polyLine = QLineF(p1, p2);
QLineF::IntersectionType intersectionType =
polyLine.intersects(centerLine, &intersectPoint);
if (intersectionType == QLineF::BoundedIntersection)
break;
p1 = p2;
}
setLine(QLineF(intersectPoint, myStartItem->pos()));
//! [5] //! [6]
double angle = std::atan2(-line().dy(), line().dx());
QPointF arrowP1 = line().p1() + QPointF(sin(angle + M_PI / 3) * arrowSize,
cos(angle + M_PI / 3) * arrowSize);
QPointF arrowP2 = line().p1() + QPointF(sin(angle + M_PI - M_PI / 3) * arrowSize,
cos(angle + M_PI - M_PI / 3) * arrowSize);
arrowHead.clear();
arrowHead << line().p1() << arrowP1 << arrowP2;
//! [6] //! [7]
painter->drawLine(line());
painter->drawPolygon(arrowHead);
if (isSelected()) {
painter->setPen(QPen(myColor, 1, Qt::DashLine));
QLineF myLine = line();
myLine.translate(0, 4.0);
painter->drawLine(myLine);
myLine.translate(0,-8.0);
painter->drawLine(myLine);
}
}
//! [7]
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