@Oatmeal I guess you already solved your issue since 9 months passed but I experienced same issue today and solved it eventually so I want to share it anyway. Instead of using below code self.setFlag(QGraphicsItem.ItemIsMovable, True) self.setFlag(QGraphicsItem.ItemIsSelectable, True) self.setFlag(QGraphicsItem.ItemIsFocusable, True) self.setFlag(QGraphicsItem.ItemSendsGeometryChanges, True) using below code did the trick for me setFlags(QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsMovable | QGraphicsItem.ItemIsFocusable | QGraphicsItem::ItemSendsGeometryChanges);

Early answer Thank you . I try to implement their own line class .