Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Standard File and Desk Accessories
Message-ID: <7547@hoptoad.uucp>
Date: 6 Jun 89 01:34:32 GMT
References: <50967@tut.cis.ohio-state.edu>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 38

In article <50967@tut.cis.ohio-state.edu> Todd A Hitt
<thitt@cis.ohio-state.edu> writes:
>Has anybody used a non-standard dialog box with SFPPutFile?  I would like
>to add a check box to the bottom of my PutFile dialog box.  In my dlgHook
>procedure I can toggle this item, but...how does one get the status of
>whether the check box was checked after SFPPutFile returns?
>
>I can't use a global variable in a Desk Accessory.  I've tried using the
>dialog's refCon - which causes Standard File to crash.

Yes, strangely enough, Standard File sets its dialog's refCon to one
and then crashes if it's changed.  Maybe someone at Apple could
enlighten us as to the reasons.

Globals can be used in desk accessories.  It's pretty easy with
LightSpeed C, but fairly tricky with MPW C.  If you really can't do
this, then there are some other tricks.  One thing would be to save the
contents of one byte of ApplScratch or ToolScratch before going into
Standard File, then setting it from inside Standard File, then
extracting it after leaving and restoring the old value.  Another way
is to write directly into your DA's code space, using PC-relative
instructions.  This is pretty easy in assembly.

The above approaches also have a decent chance of breaking on future
systems....

Probably the best way is to use your DA's dCtlStorage field, or your DA
window's refCon.  The dCtlStorage field will be a bit tricky to get at
inside the Standard File hook, but you should be able to find your
dialog window very easily, and so find its refCon -- it's the
nextWindow field of the Standard File dialog.  (Some sophisticated
approaches to DA windows might change that, but for most DAs, you will
always be bringing up Standard File right in front of the DA window.)
-- 
Tim Maroney, Consultant, Eclectic Software, sun!hoptoad!tim
"Women's wages are 56% of men's -- but that's not necessarily evidence
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