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Useful RfCon
- To: info-macl@cambridge.apple.com
- Subject: Useful RfCon
- From: blakem@world.std.com (Blake Meike)
- Date: Wed, 15 Aug 90 10:46:25 -0400
The story so far: I asked how to save object pointers in
control refcons, Andrew pointed out that after a garbage collection
any such pointer would be junk.
Uh, oh. Ok, I won't try that.
Well, the idea was to provide a scroll bar action proc with a way
of getting in touch with the object that represents it in the Lisp
world. I just looked at some other examples of how to do this,
and to my huge surprise, I found this:
(defobfun (do-scroll *scroll-bar*) ()
(....))
(defpascal scroll-proc ((my-control :ptr) (partCode :word))
(do-scroll))
Why does this work? Why doesn't scroll-proc have
to (ask <somebody> (do-scroll))?
I think it accomplishes what I want to accomplish, but I sure
blazes don't see why.
Blake Meike
blakem@world.std.com