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;
  }