Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!dlyons
From: dlyons@Apple.COM (David A. Lyons)
Newsgroups: comp.sys.apple2
Subject: Re: problems positioning cursor in window
Message-ID: <52617@apple.Apple.COM>
Date: 9 May 91 03:26:43 GMT
References: <3520@kluge.fiu.edu>
Organization: Apple Computer Inc., Cupertino, CA
Lines: 48

In article <3520@kluge.fiu.edu> acmfiu@serss0.fiu.edu (ACMFIU) writes:
>i have the following window on the desktop
>
>	-------------------------------------------------
>	|		title				|
>	-------------------------------------------------
>	| *						|
>	|	**					|
>	|						|
>	|						|
>	-------------------------------------------------
>
>for now, disregard * and **.
>
>i create the window with _NewWindow2. i then want to write a string to
>the upper left corner of the window (where * is located). so, i just
>_WriteCString my string and it appears there. now, as far as i know, *
>has local coordinates (0, 0). so, if i _LocalToGlobal (0,0) and then
>_MoveTo the result of this, i should appear where * is. however, this does
>not work. the string appears where ** is located after the _MoveTo. 
>
>someone want to explain what's going on?
>
>albert

Tim Meekins is right--by converting (0,0) to global coordinates and then
using the result in MoveTo, you're drawing the string at a position
relative to the top left of your window that *depends on* the location
of your window on the screen.

The point of local coordinates is that you usually don't have to worry
about different coordinate systems.  MoveTo works within a port, so it
uses local coordinates.

The only thing to watch out for is that text is mostly drawn *above* the
pen.  You need to MoveTo the *bottom left* of where you want your text,
like MoveTo(2,10).  You may want to use GetFontInfo and/or GetFontGlobals
to find the ascent, descent, and leading for your font are; or you may
want to just hard-code the values for Shaston 8.  Depends on your
application and how much work you want to do to be flexible.

-- 
David A. Lyons, Apple Computer, Inc.      |   DAL Systems
Apple II System Software Engineer         |   P.O. Box 875
America Online: Dave Lyons                |   Cupertino, CA 95015-0875
GEnie:DAVE.LYONS  CompuServe:72177,3233 Internet:dlyons@apple.com

My opinions are my own, not Apple's.