Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!lll-winken!sun-barr!decwrl!shelby!daemon
From: combs@sumex-aim.stanford.edu (Dave Combs)
Newsgroups: comp.sys.next
Subject: Re: Bitmaps from views
Message-ID: <867@shelby.Stanford.EDU>
Date: 22 Nov 89 16:45:56 GMT
Sender: daemon@shelby.Stanford.EDU
Lines: 21

Ali,
Thanks for your response regarding Bitmaps.  After I sent my note out,
I realized that I'd left out one crucial piece of information, namely that
the image that I'm trying to place in a bitmap consists of a whole 
hierarchy of views, rather than just a single view.  As I understand it,
doing a lockFocus to an offscreen bitmap works fine in the example you
gave precisely because nothing changes the lockFocus once it's been done
in drawSelf::.  In particular, there is no traversal of the View hierarchy,
(as with the "display" msg, which keeps adjusting the focus as it goes down
a View hierarchy [at least I assume that's what's happening.  Correct?])

To restate the problem for anyone who missed it - to speed up some
interactive drawing operations (for a "link and node editor" I'm developing)
I would like to cache certain images in Bitmaps.  It appears that the
standard "cache to offscreen window, then composite" trick only works
when the image being cached is only a single view, whereas each of my
images is a hierarchy of views.  What's the best way to get these to a 
Bitmap?

Thanks for any advice,
Dave  (combs@sumex-aim.stanford.edu)