Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!husc6!cca!dee
From: dee@cca.CCA.COM (Donald Eastlake)
Newsgroups: comp.sys.mac.programmer
Subject: Re: MultiFinder and the event mask
Message-ID: <32058@cca.CCA.COM>
Date: 12 Aug 88 12:03:17 GMT
References: <3469@polya.Stanford.EDU> <15452@apple.Apple.COM>
Reply-To: dee@CCA.CCA.COM (Donald Eastlake)
Organization: Computer Corp. of America, Cambridge, MA
Lines: 39

In article <15452@apple.Apple.COM> tecot@apple.com.UUCP (Ed Tecot) writes:
>In article <3469@polya.Stanford.EDU> rothberg@polya.Stanford.EDU (Edward Rothberg) writes:
>> . . .  I call SetEventMask() with the appropriate parameter.
>>My application works perfectly with UniFinder, and it works just fine when
>>I'm running alone (just it and the Finder) in MultiFinder.  However, when I
>>start up another application in the background, the foreground application
>>starts losing keyUp events.  . . .
>The system event mask is a system property, not an application property.  The
>reson for this is that the event mask gets applied when the event is posted,
>not retrieved.  Its use really does not entirely make sense in the MultiFinder
>environment.
>However, to answer your question, MultiFinder does not switch the system
>event mask for each application.  Chances are that the application you launch
>sets the system event mask itself.


This sounds like nonsense to me.

Many applications diddle the System Event Mask a little.  Inside
MacIntosh gives the application complete licence to turn on or off at
least the key-up bit in this Mask although it discourages diddling
anything else.

(If you are claiming that events in the system event queue are the
property of the "system" until an application actually senses them with
Get/Wait/Avail then applications should also refrain from ever doing a
FlushEvents, at least under MultiFinder (oops, I forgot you are never
supposed to check if you are under MutiFinder.  I guess you are supposed
to check the "system owns the system event queue" service ....))


If MultiFinder does not handle this properly by giving applications the
impression that they own the machine when it easily could, I think its a
bug in MultiFinder.

-- 
	+1 617-969-9570		Donald E. Eastlake, III
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