node.h Example File

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 #ifndef NODE_H
 #define NODE_H

 #include <QGraphicsItem>
 #include <QList>

 class Edge;
 class GraphWidget;
 class QGraphicsSceneMouseEvent;

 class Node : public QGraphicsItem
 {
 public:
     Node(GraphWidget *graphWidget);

     void addEdge(Edge *edge);
     QList<Edge *> edges() const;

     enum { Type = UserType + 1 };
     int type() const override { return Type; }

     void calculateForces();
     bool advancePosition();

     QRectF boundingRect() const override;
     QPainterPath shape() const override;
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;

 protected:
     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;

     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
     void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) override;

 private:
     QList<Edge *> edgeList;
     QPointF newPos;
     GraphWidget *graph;
 };

 #endif // NODE_H