[cvs-nhc98] Refactor the expression-squashing code into the paintOne r

[Malcolm Wallace]

malcolm: Mon Jul  1 19:00:20 CEST 2002

Update of /usr/src/master/nhc/src/hat/tools
In directory hinken:/tmp/cvs-serv12973

Modified Files:
	HatTrail.hs 
Log Message:
Refactor the expression-squashing code into the paintOne routine,
so that the expression is pretty-printed only once at the final size,
instead of twice.

Also, make some fixes to the shrink/expand behaviour when an expression
has been squashed.  Previously, this led to a garbled screen, and
sometimes a disappearing selection.