Problem with ScrolledWindow in Windows

[Ari Jolma <ari jolma tkk fi>]

Hello,

I'm developing an application (in fact a set of modules) with Gtk2-Perl,
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. The image
shows a visualization of geospatial datasets and my code sets (i.e.,
does not create) it from a pixbuf or pixmap every time the user zooms in
or pans. The image is ok but on some occasions the ScrolledWindow does
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. The view is usually restored by a
single click on the scrollbars, i.e., panning the view a bit.

I'm using the ScrolledWindow in such a way that I set the scrollbars by
setting the size request of the image to be as large as the whole data
would require, and then setting the alignment of the image so that it
gets positioned in the visible area. On some very rare occasions the
image is not correctly positioned, and that might be the reason for my
problem, but, on the other hand, it never happens in Linux. I guess the
set_size_request, set_alignment is the correct way to use
ScrolledWindow? I tried to switch to controlling the scrollbars
directly, but could not make it to work quickly.

I guess my next step is to dig into gdk-win32 or something. Any help and
advice how to proceed and where to start would be appreciated. How do I
debug the screen updating of ScrolledWindow? This problem persists in
the latest 2.10.6 version of gtk+.

Regards,

Ari

-- 
Prof. Ari Jolma
Geoinformaatio- ja paikannustekniikka / Geoinformation and positioning
Teknillinen Korkeakoulu / Helsinki University of Technology
tel: +358 9 451 3886 address: POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma