arrow.h Example File

graphicsview/diagramscene/arrow.h
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 #ifndef ARROW_H
 #define ARROW_H

 #include <QGraphicsLineItem>

 #include "diagramitem.h"

 class QGraphicsPolygonItem;
 class QGraphicsLineItem;
 class QGraphicsScene;
 class QRectF;
 class QGraphicsSceneMouseEvent;
 class QPainterPath;

 class Arrow : public QGraphicsLineItem
 {
 public:
     enum { Type = UserType + 4 };

     Arrow(DiagramItem *startItem, DiagramItem *endItem,
       QGraphicsItem *parent = 0);

     int type() const override { return Type; }
     QRectF boundingRect() const override;
     QPainterPath shape() const override;
     void setColor(const QColor &color) { myColor = color; }
     DiagramItem *startItem() const { return myStartItem; }
     DiagramItem *endItem() const { return myEndItem; }

     void updatePosition();

 protected:
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0) override;

 private:
     DiagramItem *myStartItem;
     DiagramItem *myEndItem;
     QColor myColor;
     QPolygonF arrowHead;
 };

 #endif // ARROW_H