Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!talos!kjones
From: kjones@talos.uucp (Kyle Jones)
Newsgroups: comp.emacs
Subject: Re: Question on truncate-lines
Message-ID: <1989Oct5.161430.18234@talos.uucp>
Date: 5 Oct 89 16:14:30 GMT
References: <-285219997@hpcupt1.HP.COM>
Reply-To: kjones@talos.uu.net
Lines: 21

Mark Diekhans writes:
 > I would like to have a function to toggle the value of the truncate-lines
 > variable.  Unfortunatly doiung a setq or set-variable within a function
 > does not cause the window to be redrawn the was doing a M-x set-variable
 > command.  I am forced to use the following function, which redraws the
 > display after toggling the variable.  I don't want to wait for the entire
 > screen to be redrawn.  How do I force just the current window to be redrawn?
 > 
 >         (defun toggle-truncate-lines ()
 >           "Toggle the value of truncate-lines"
 >           (interactive)
 >           (setq truncate-lines (not truncate-lines))
 >           (redraw-display))

Change (redraw-display) to (scroll-up 0).  This is voodoo, very much
like the

  (set-buffer-modified-p (buffer-modified-p))
  (switch-to-buffer (other-buffer))

incantation used to trick Emacs into updating mode lines.