diagramscene.h Example File

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  #ifndef DIAGRAMSCENE_H
  #define DIAGRAMSCENE_H

  #include <QObject>
  #include <QGraphicsScene>

  class DiagramItem;
  class QGraphicsSceneDragDropEvent;
  class QGraphicsViewItem;

  class DiagramScene : public QGraphicsScene
  {
      Q_OBJECT

  public:
      DiagramScene(QObject *parent = 0);

  signals:
      void itemMoved(DiagramItem *movedItem, const QPointF &movedFromPosition);

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

  private:
      QGraphicsItem *movingItem;
      QPointF oldPos;
  };

  #endif