about the contextMenuEvent in graphics view framework

I have reimplemented the contextMenuEvent function both in QGraphicsItem、QGraphicsScene and QGraphicsView，now when i click the right button in the view,which context menu is shown?how does the graphics view framework deliver events in item,scene and view?

QGraphicsView is a QWidget and receives QContextMenuEvent. QGraphicsView converts that to a QGraphicsSceneContextMenuEvent and sends it to the scene. The scene is responsible for sending the event to all items at event position until one item accepts the event.