node.cpp Example File

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 #include "node.h"
 #include "stickman.h"

 #include <QRectF>
 #include <QPainter>
 #include <QGraphicsSceneMouseEvent>

 Node::Node(const QPointF &pos, QGraphicsItem *parent)
   : QGraphicsObject(parent), m_dragging(false)
 {
     setPos(pos);
     setFlag(QGraphicsItem::ItemSendsGeometryChanges);
 }

 Node::~Node()
 {
 }

 QRectF Node::boundingRect() const
 {
     return QRectF(-6.0, -6.0, 12.0, 12.0);
 }

 void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
 {
     painter->setPen(Qt::white);
     painter->drawEllipse(QPointF(0.0, 0.0), 5.0, 5.0);
 }

 QVariant Node::itemChange(GraphicsItemChange change, const QVariant &value)
 {
     if (change == QGraphicsItem::ItemPositionChange)
         emit positionChanged();

     return QGraphicsObject::itemChange(change, value);
 }

 void Node::mousePressEvent(QGraphicsSceneMouseEvent *)
 {
     m_dragging = true;
 }

 void Node::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 {
     if (m_dragging)
         setPos(mapToParent(event->pos()));
 }

 void Node::mouseReleaseEvent(QGraphicsSceneMouseEvent *)
 {
     m_dragging = false;
 }