Hmm, I don't understand it still :/
As far as I know, code you suggest actually zooms the view - it's fine, but the problem is that scrollbars stay untouched. I guess this is why I stick to ScrollZoomer::zoom (being QwtPlotZoomer::zoom I guess) - it happens to manage scrollbars and other things fine. I don't know if I'm right, but with my code from the opening post I wanted just to feed the "nice working ScrollZoomer from realtime example" with the right zooming rectangle. That would leave me with ScrollZoomer code untouched because it's working fine for me. As far as I understand, your approach, Uwe, is a little bit different, right? I just thought it's going to work, when I get the idea when is the yLeft axis rescaled - I would stop it from rescaling and it will be it. Problem is: is that even possible?
Thank you for your patience anyways