Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!homxb!whuts!mtune!rutgers!princeton!udel!gatech!mcnc!thorin!unc!steele
From: steele@unc.cs.unc.edu (Oliver Steele)
Newsgroups: comp.sys.mac
Subject: Re: Setting cursor position and mouse speed.
Message-ID: <888@thorin.cs.unc.edu>
Date: 27 Jan 88 01:44:40 GMT
References: <2532@auscso.UUCP> <7272@apple.UUCP>
Sender: news@thorin.cs.unc.edu
Reply-To: steele@unc.UUCP (Oliver Steele)
Organization: University Of North Carolina, Chapel Hill
Lines: 18

[dgold@apple.UUCP (David Goldsmith) writes that setting the mouse position
directly, and using undocumented low memory globals in general, are poor
ideas and are likely to cause a program to break in the future.]

I agree with your general point about keeping as many globals as possible
verboten, especially now that multitasking approaches, but how does Apple
recommend for people writing paint programs, for instance, to show that a
grid or other constraining factor is in effect?  I notice that there's
already some inconsistency -- constraining to a grid, in many programs,
makes the mouse street-wise*; but constraining tool motion to an axis
doesn't constrain the cursor to that axis.  I also notice that HyperCard
plays with exactly these low-memory globals; is this OK because HyperCard
is system software (1/2:-)?

----------------------------------------------------------------------------
Oliver Steele				  ...!{decvax,ihnp4}!mcnc!unc!steele
							   steele@cs.unc.edu
*Taxi-cab geometry, of course.