🚀 go-pugleaf

In article <sVJ1zsy00UgLwe00=B@andrew.cmu.edu> rj0z+@andrew.cmu.edu writes:
>   Does anybody know how to move the cursor from within an application. (I
>don't mean with the mouse, but by actually changing the coordinates with a
>program). I also need to know if it is possible to constrain the motion of
>the cursor to a smaller rectangle than the screen.

I spent a while figuring this out last year, and the answer is yes, but
only if you want to sacrifice compatibility.  There is a set of
undocumented low memory globals on the Mac 128K, 512K, and Plus that
store cursor info, but I have no idea if they're available on the SE or
the II, and there's no guarantee that they'll be there on future
machines.

CrsrPin at $834 is a rectangle the cursor is pinned to, initially the
size of the screen (I don't know about multiple-screen systems).  If you
make it larger than the screen the Mac crashes.  When changing cursor
info, set the byte-size boolean CrsrNew at $8CE and wait a tick for the
cursor to be updated.  CrsrCouple, a byte-size boolean at $8CF, is true
if the cursor is coupled to the mouse.  Unset it if you don't want the
user using the mouse.  I couldn't figure out how to move the cursor
other than temporarily setting CrsrPin to a tiny rectangle at the point
I wanted the cursor.

Carefully consider why you want to move the cursor.  I used a system
called Geos on my friend's Commodore 64 that always helpfully moved the
cursor to the point where it thought I wanted it.  It drove me crazy.
In addition, restricting the cursor's movement has shades of (gasp)
MODES, and works against MultiFinder.  I think Apple has good reason not
to document the cursor routines.

-----
Lee Choquette				u-lchoqu@ug.utah.edu
University of Utah Computer Center	CHOQUETTE@UTAHCCA.BITNET
MEB 3440				utah-gr!utah-ug!u-lchoqu
Salt Lake City, UT  84112		(801) 581-8504