🚀 go-pugleaf

I have modified a textedit-based programming editor to
support tabs  using the Quickdraw StdText and StdTxtMeas
routines.  My patches to these routines treat tabs as
variable width characters using a simplified version 
of the routines given in a MacTutor article from about
a year ago.  My routines work well on the Mac Plus
and SE with system 3.2, 4.1 and 4.2. They also work
on the Mac II  ---but only if the Mac II is in 2-color
mode.  IF I switch to other modes, text is not properly
displayed as input is  entered.   However, if the screen
is invalidated and redrawn all is ok. 
Anyone have any ideas?   What is different about 
the quickdraw routines when in other than 2-color
mode?   IM Vol five does not mention anything about
stdText or stdTxtMeas acting  differently in 
multi-bit modes?

I also saw  something on the net to the effect that
modifying textedit  to support tabs was verboten. 
There is nothing to this effect in the latest 
compatibility guidelines.  Am I doomed to failure
or what?

Mark Borgerson
Dept. Computer Science
Oregon State University

Disclaimers are for opinions.  The material above is factual.