Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!ll-xn!ames!oliveb!pyramid!voder!apple!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Finding MouseMoved Events
Message-ID: <9300@apple.Apple.Com>
Date: 2 May 88 17:58:30 GMT
References: <8769@eleazar.Dartmouth.EDU> <3068@saturn.ucsc.edu> <23826@ucbvax.BERKELEY.EDU>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Organization: Advanced Technology Group, Apple Computer
Lines: 33

In article <23826@ucbvax.BERKELEY.EDU> oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster) writes:
>In article <3068@saturn.ucsc.edu> alibaba@ucscb.UCSC.EDU (Alexander M. Rosenberg) writes:
>>described, using GetMouse, you might take a look at the low-memory globals.
>>I think that there is a global there that might do some of the work for you.
>
>Of course, if you do this you will instantly be incompatible with

The low memory mouse variables are not documented very well (if at all),
which means that they can be changed in the future.

You should definitely call a trap to get the mouse position.  GetMouse will
return the mouse in local coordinates, which is probably not what you want.
Instead, all OSEventAvail with a mask of 0.  OSEventAvail returns the mouse
in global (screen) coordinates.  

If you are really concerned about performance, then use GetTrapAddress to
find out the address of the OSEventAvail trap and call it directly.  The
only risk in doing this is that some other code might patch OSEventAvail and
you wouldn't be using the patched code.  (This won't cause system problems,
because any system patches are installed before INITs are run.  The problem
might show up as an incompatibility with some other INIT.)

>If you are running under multifinder, WaitNextEvent returns mouseMoved as
>a nullEvent with a bit set  (in the message field?, in the modifers

It returns an app4Evt, not a null event.  The high byte of the message field
distinguishes a mouse moved event from a suspend/resume event.

-- 
		 Larry Rosenstein,  Object Specialist
 Apple Computer, Inc.  20525 Mariani Ave, MS 27-AJ  Cupertino, CA 95014
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