[plt-scheme] Question on Canvas object in GUI programming

Hello,

I want to implement something like this:
  1. Display a picture in a Canvas on a Frame;
  2. User can click on the picture;
  3. I want to get the color of the pixel that user clicked;

For Canvas object,  Using what method or what strategy, that I can get the
pixel info?
Thanks a lot for the help!

best regards,
Linda Lian
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20071218/8f05a3d2/attachment.html>