Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!sdd.hp.com!ucsd!nosc!cod!sampson
From: sampson@cod.NOSC.MIL (Charles H. Sampson)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Drawstring Problem
Message-ID: <2428@cod.NOSC.MIL>
Date: 31 Oct 90 18:32:59 GMT
References: <gb6MX8600UhWQ0dklE@andrew.cmu.edu-  <10727@goofy.Apple.COM-
Reply-To: sampson@cod.nosc.mil.UUCP (Charles H. Sampson)
Organization: Computer Sciences Corporation
Lines: 25

In article <10727@goofy.Apple.COM-  stevec@Apple.COM (Steve Christensen) writes:
- 
-  rg2c+@andrew.cmu.edu (Robert Nelson Gasch) writes:
-- 
--  [Description of some difficulties in using Drawstring to overwrite
--   text]
- 
- There are a few ways of doing this depending on how you want the display to
- look.  You can use TextBox() and specify a bounding rectangle big enough to
- hold the string you'd display.  You'd call StringWidth() to find out how wide
- the string is and then build a rectangle that wide.  The down side to this is
- that whatever's behind the string gets erased each time.  Another way to do
- this is to draw the string in XOR mode and then draw it again (to erase it)
- just before updating the display.  This way is better if something's drawn
- "behind" the string...
- 
     Redrawing in XOR mode will erase the previously drawn text, but it
won't refresh whatever was "behind" the string.  When the new text is
drawn the background will have holes where the old text was.  However,
for the simple problem, where no background is involved, this looks like
the nicest solution; you don't have to worry about figuring out how to
handle the tail of the old text, as would be necessary if SrcCopy mode
were used.

                              Charlie