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| |
| #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] |