[plt-scheme] bitmaps, buttons, transparency

From: Ed Cavazos (proteus at theworld.com)
Date: Mon May 19 09:31:39 EDT 2003

Thanks for the info Matthew.

Practically, this is no big deal. With graphics files, there's plenty
of flexibility. I can convert file formats as needed and in this case,
I can just modify the bitmaps to have a decent background.


Matthew Flatt <mflatt at cs.utah.edu> writes:

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> At Sun, 18 May 2003 11:22:58 -0500 (CDT), Ed Cavazos wrote:
> > I've got some xpm bitmaps that I'm using as the label for some
> > buttons. When I view these bitmaps in image viewers, they appear to
> > have transparent backgrounds. When I stick them in a button, those
> > areas appear black.
> > 
> > Does anyone have some example code they can share for how to get the
> > button background to be the same as (get-panel-background) ?
> There are two problems:
>  * MrEd doesn't currently recognize transparency when loading XPM
>    files. (It just uses whatever color is associated with the
>    transparent index.)
>  * button% doesn't currently recognize transparency in bitmap labels.
> Both are things we'd like to fix, but neither fix is likely to happen
> soon.
> Matthew

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