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From: sirkm@ssyx.ucsc.edu (Greg Anderson)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Finding the size of the screen under Multifinder/Color QD
Message-ID: <10164@saturn.ucsc.edu>
Date: 3 Jan 90 18:03:20 GMT
References: <10139@saturn.ucsc.edu> <9429@hoptoad.uucp> <1102@urbana.mcd.mot.com>
Sender: usenet@saturn.ucsc.edu
Reply-To: sirkm@ssyx.ucsc.edu (Greg Anderson)
Organization: UC Santa Cruz; Division of Social Sciences
Lines: 36

In article <1102@urbana.mcd.mot.com> willcox@urbana.mcd.mot.com (David A Willcox) writes:

[quoted references to invalid screenbits.bounds deleted]

>This sounds a bit like what happened when I tried to use screenBits
>from within an XCMD.  The problem, of course, was that I hadn't called
>InitGraf() (I hope that's the right name) from within my XCMD, and I
>was seeing a local copy of screenBits that had not been initialized.

I know  it's illegal to call InitGraf() from within XCMD's, but can I
call it from within a DA?  It seems like I would have the same problems
you experienced.

If I cannot call InitGraf() from within my DA, then how can I find the
size of the screen?  screenbits.bounds can be used under UniFinder, and
I can look at the main screen's gDevice on a system with color quickdraw,
but that still leaves me stuck in Multifinder systems that don't have
color quickdraw.

>Can anyone tell me, is there a better way to get at global variables
>such as screenBits from within an XCMD?

Sort of -- make callbacks to HyperCard.  This won't always get you what you
want, but it can often be very helpful.  For example, I have an XCMD that
centers its dialog on the HyperCard window by making a callback that asks
HyperCard where its window is.  Under HyperCard, I find it much nicer to
have dialogs centered on the HyperCard window rather than the whole screen;
that way they look like they're part of HyperCard.  Dialogs that center
on the whole screen look like system messages.

If you'd like, I could send you the source.

  ___\    /___               Greg Anderson              ___\    /___ 
  \   \  /   /         Social Sciences Computing        \   \  /   /
   \  /\/\  /    University of California, Santa Cruz    \  /\/\  /
    \/    \/              sirkm@ssyx.ucsc.edu             \/    \/