Reimplement of resizeEvent

[marcel]

and this one is the final goal

Yes, you can do this with QGraphicsView.

The main drawbacks of the method you're currently using are:
- If the document gets bigger you will have to add a QScrollArea manually;
- You have to manage image positions manually at resize and scroll.
- Zooming would be very hard to implement

QGraphicsView offers all of the above by default, with simple to use API, so you should think about using it.
You could event interact with those components in your document( move them around, change connections, etc ).

Regards