Path: utzoo!utgpu!water!watmath!clyde!saf@moss.ATT.COM
From: saf@moss.ATT.COM
Newsgroups: comp.sys.mac.programmer
Subject: Re: Meaning a few of the SIZE bits w/ Multifinder
Summary: SIZE resource
Keywords: Multifinder SIZE
Message-ID: <23241@clyde.ATT.COM>
Date: 13 Mar 88 16:57:18 GMT
References: <1988Mar9.111506.1858@mntgfx.mentor.com>
Sender: nuucp@clyde.ATT.COM
Lines: 28

The bits in the SIZE resource for MF are:

	14 - accepts suspend/resume events
	12 - accepts background null events
	11 - aware of MF

Turning on suspend/resume gets you a suspend event so you can convert
your scrap to universal format - then next time you ask for an event,
you go to sleep.  This is for efficiency - MF will work around it if
you can't handle syspend/resume.

Background nulls imply that you will call for an event about 10 times
a second - this allows the foreground job to stay responsive.  I'm
guessing but I imagine failure to set this will keep you asleep unless
you are on top (i.e., the current job).

MF awareness is tricky - you have to treat suspend/resume as implying
activate/deactivate ONLY if you are they top-most job.  If a DA is on
top, you have to pass the appropriate activate/deactivate event to it
using SystemEvent().

I found that just setting "background" and the minimum/preferred sizes
lets "well-behaved" code run just fine under MF.  Note that CurrentA5
will NOT be valid any more!!!  You have to make your own.  If you've
never heard of CurrentA5 don't worry about it.  It's an assembly
language thing used by interrupt handlers.

	Steve Falco   moss!saf   saf@moss.ATT.COM