I was thinking I'd eventually need more than two states, and so hadn't considered a checkbox. Happily, today's problem only requires the two states, and so a little rework has yielded what looks to be a better solution. Thanks for the suggestion. <div class="gmail_quote">On Tue, Feb 21, 2012 at 10:53 AM, Matthew Flatt <<a href="mailto:mflatt@cs.utah.edu">mflatt@cs.utah.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The idea of `set-state-normal' and `set-state-selected' sounds like a `check-box%' rather than a `button%'. Otherwise, there's no way to change the background color of a `button%' instance. Classes like `button%' correspond to platform-specific GUI widgets that typically either don't support or strongly discourage the possibility of changing a button's background (because button colors are normally determined by a theme). You can create a `canvas%' that draws a custom button image, in which case you have complete control over how the button looks and reacts, but there isn't much of an in-between level of customization in the current toolkit. At Tue, 21 Feb 2012 00:25:52 -0700, Kieron Hardy wrote: > Hi all, > > How do I change the background color (and/or style of border etc.) of a GUI > button? Given the code below, what should I put in the set-state-x methods > to indicate a difference between a normal and selected button? > > Also any comments on program style and/or substance are appreciated (I > apologize in advance if the layout offends). > > Cheers, > > Kieron. > > **** > > #lang racket/gui > > (define color-button% > (class button% > (inherit refresh) > > (define toggle > (let ([f #f]) > (lambda () > (set! f (not f)) > f > ) > ) > ) > > (define (set-state-normal) > (printf "color-button%: set-state-normal:\n") > ; ??? ; set background color to normal > (refresh) > ) > > (define (set-state-selected) > (printf "color-button%: set-state-selected:\n") > ; ??? ; set background color to red > (refresh) > ) > > (define click-callback > (lambda (button control-event) > (printf "color-button%: click-callback:\n") > (if (toggle) > (set-state-selected) > (set-state-normal) > ) > ) > ) > > (super-new (callback click-callback)) > > ) > ) > > (define f (new frame% > [label "Colored Button"] > [min-width 100] > [min-height 200] > ) > ) > > (define b (new color-button% > [parent f] > [label "push me"] > ) > ) > > (send f show #t) > ____________________ > Racket Users list: > <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a> </blockquote></div>