ComboBox fails to show on one computer, but works on others...

I have an end user experiencing something odd.  I have a few dialogs that
use ComboBoxes.  On one dialog, and a subclass of it that has its own view
(based on the parent view) the ComboBox does not show on one of their
computers.  There is just an empty space where it would normally be.  The
computer is running Windows XP with the latest patches.  Every other
computer (with XP, NT, ME, 2000) I have used our program on displays the
ComboBox there correctly. At first I thought the offending computer might
have a corrupt GUI library or something, however it displays ComboBoxes in
other parts of the program with no problem.  Has anyone else experienced
anything like this?  I suspect that if I fiddle with the view (maybe
recreate the ComboBox, or the whole view if needed) I might be able to fix
it.  However I would love to understand this problem better.  Any ideas?

Chris

Christopher,

No real insights but the offending computer isn't using large (or non
standard) screen fonts is it?

Best Regards,

Andy Bower
Dolphin Support
http://www.object-arts.com
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"Andy Bower" <[hidden email]> wrote in message
news:[hidden email]...
> Christopher,
>
> > I have an end user experiencing something odd.  I have a few dialogs
that
> > use ComboBoxes.  On one dialog, and a subclass of it that has its own
view
> > (based on the parent view) the ComboBox does not show on one of their
> > computers.  There is just an empty space where it would normally be.
The
> > computer is running Windows XP with the latest patches.  Every other
> > computer (with XP, NT, ME, 2000) I have used our program on displays the
> > ComboBox there correctly. At first I thought the offending computer
might
> > have a corrupt GUI library or something, however it displays ComboBoxes
in
> > other parts of the program with no problem.  Has anyone else experienced
> > anything like this?  I suspect that if I fiddle with the view (maybe
> > recreate the ComboBox, or the whole view if needed) I might be able to
fix
> > it.  However I would love to understand this problem better.  Any ideas?
>
> No real insights but the offending computer isn't using large (or non
> standard) screen fonts is it?

Unfortunately that does not seem to be the problem.  I made a test EXE with
just the dialog to experiment.  I then removed and then recreated the
ComboBox, and had the same problem.  I am just going to keep experimenting.
I will post if I can figure out the problem.

Chris

"Christopher J. Demers" <[hidden email]> wrote in
message news:bfs1up$i87h1$[hidden email]...
> "Andy Bower" <[hidden email]> wrote in message
> news:[hidden email]...
> >
> > No real insights but the offending computer isn't using large (or non
> > standard) screen fonts is it?
>
> Unfortunately that does not seem to be the problem.  I made a test EXE
with
> just the dialog to experiment.  I then removed and then recreated the
> ComboBox, and had the same problem.  I am just going to keep
experimenting.
> I will post if I can figure out the problem.

Just in case it helps narrow down the issue, the reason Andy mentioned the
large fonts is because of a previous bug with comboboxes:

"#68: Drop-down lists fail to drop down on 95/98/NT (e.g. Tip of The Day,
Lagoon wizard) when large fonts selected.

Fix Notes: Turns out to be because the use of large fonts means that the
layout manager needs to resize the view when opened. This causes the
rectangle of the combobox to be changed. However the rectangle of a combobox
(that is not in simple mode) has to be _set_ to the rectangle that includes
the drop-down, as well as the edit field, although the rectangle reported by
the control does not include the drop-down. Consequently an override of
#rectangle: (and extent:) is needed to prevent the combobox being sized down
to the size of the edit field alone. ..."

Although the low defect number indicates that this is an old defect, it was
only fixed in 5.0 PL2 (i.e. quite recently).

Regards

Blair