How to rotate correctly after changing the QGraphicsItem size

[gangyi11]

Hello.

I'm making a Diagram program and for days I'm stuck with some issue:
i have a customer QMyGraphicsRectItem which inherit QGraphicsItem ,when i drawing a rect in scene, Followed by rotate and then resize .Again this time of rotation, rect position will be change，i donot know why?

item.zip is Screen recording program。It can be found that there is a significant jitter in the second rotation。
drawcli.zip is src.

I'd appreciate any advice. Thanks!

mousePressEvent call setTransformOriginPoint change item's OriginPoint
1.png


mouseMoveEvent change angle
2.png

demo ui
3.png