[racket-dev] Different refresh behavior between 4.2.5 and 5.0+

From: Doug Williams (m.douglas.williams at gmail.com)
Date: Thu Aug 4 16:55:54 EDT 2011

I would like to migrate my production machines from the current PLT Scheme
4.2.5 to the latest release of Racket.However, there is one annoying
graphics inconsistency with graphics refresh that is giving me problems. For
some of my graphics programs, I update many canvases - some visible and some
not, depending on what tabs are selected - and afterwards I just issue one
(send the-frame refresh). This works fine in 4.2.5. However, in 5.0+ (at
least the last couple versions), some of the canvases update and some don't.
One can switch to a different tab and back to force the repaint and that
works, but obviously annoys the users. I haven't experimented enough to
track down exactly which do and which don't. [I rolled my production
machines back to 4.2.5 and haven't moved that code to a development machine
to play with it.]

There seem to be a couple of open bugs reports that may or may not be
related - 11759 and 12065.

On my development code that has a similar problem I moved the refreshes down
to the individual canvases (as they are updated) and that works. But it
seems that one refresh of the frame at the end should work just a well. Is
this a new feature that I missed somewhere or a bug?

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/dev/archive/attachments/20110804/68904845/attachment.html>

Posted on the dev mailing list.