If qt uses double buffer, where are these buffers in case of QGraphicsview ?

[tonnot]

I'm trying to use the already drawed data on Qgraphicsview.
In case I have to edit one item of 100000 , I think it'd must exist a posibility of having an automatica 'background' buffer copy. But I don find anything related . So I'm going to do myself....

- Grabwidget are going to redraw all, so it is wasted time.
- render are going to do the same
- I'm going to try Grabwindow, but I dont understand how it is impossible (or unknowed by me) to use the actual buffer information...
Any trick ? Thanks