Re: Problem with ScrolledWindow in Windows

[Ari Jolma <ari jolma tkk fi>]

John Cupitt kirjoitti:
> On 10/13/06, Ari Jolma <ari jolma tkk fi> wrote:
> > which work in Linux but there's a nagging non-fatal problem in Windows.
> > The problem has to do with showing an image in ScrolledWindow.
> > [snip]
> > not show it, and the EventBox also seems to stop receiving events. These
> > occasions are related to the user zooming in into a very small portion
> > of the visible part of the data.
>
> Have you checked the size of the virtual window that is being
> scrolled? The win32 backend can't do virtual windows larger than 65k
> pixels in either (or both) dimensions. I have this problem too on
> large image zooms.

Maybe my explanation was not very good. The "virtual" window is really 
virtual in the sense that I always create an image, which is just the 
size of the actual visible window. The rest is just imaginary space. 
Thus the size is not an issue in this sense. And the thing works after 
it has "settled" after the first deep zoom-in, as I wrote: usually it 
only needs to pan a bit.

> I think the only known solution is to not use scrolledwindow and to do
> the clipping / panning yourself :-( Just attach two scrollbars and a
> lot of callbacks to a small drawingarea.

To use my own scrollbars would be an option but since the code works in 
Linux I'm stubbornly trying to figure out why it is not working in 
Windows. And besides, the interaction code was really difficult to code 
(I'm not a MVC guru) and I'm not looking forward to code it again with 
more moving parts...

Thanks,

Ari

> John


--
Prof. Ari Jolma
Geoinformaatio- ja paikannustekniikka
Geoinformation and positioning technology
Teknillinen Korkeakoulu / Helsinki University of Technology
POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma