[racket] Transparent area's

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Mon Oct 25 09:17:15 EDT 2010

Both in the old and new toolboxes, you can make a transparent canvas
using the 'transparent style when you create the `canvas%' object.

If I understand the issue, though, putting a `button%' instance on top
of a `canvas%' doesn't really work in either toolbox. Also, neither
toolbox currently lets you paint the background of a panel (which can
contain buttons and other controls). I think that panel drawing could
be made configurable in the new toolbox --- after everything else is in

At Mon, 25 Oct 2010 14:10:13 +0100, Noel Welsh wrote:
> I'm guessing this is a limitation of the current windowing toolkit.
> There is a new toolkit under development here:
> http://github.com/mflatt/gr2
> I'm going to look at transparency support in the new toolkit, but it
> will take me a while to find the time.
> HTH,
> N.
> BTW, Racket doesn't use CamelCase. The dash is the conventional
> separator within an identifier. like-this not LikeThis
> On Thu, Oct 21, 2010 at 10:28 AM, Christophe Vandenberghe
> <chvndb at gmail.com> wrote:
> > Hi,
> >
> > Yeah, if you want to draw some text that's fine. But even if you want to
> > import an image that has a transparent background onto a drawing canvas, it
> > does not support the transparency. It adds a background color. So that
> > doesn't work either.
> ...
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