Re: Aborting display. Is this possible?

[David Kastrup <dak@gnu.org>]

Alan Mackenzie <acm@muc.de> writes:

> Why?  Better to handle a user auto-repeating on the PageDown key.  On
> my system, auto-repeat is around 35-40 characters per second, on a
> window with 65 lines.  In my favourite mode, display can not keep up.
> If I set redisplay-dont-pause to nil and hold down PageDown, what the
> user sees is frozen for several seconds whilst display determines the
> display of every intermediate buffer position (which isn't going to
> get displayed anyway) before finally reaching point.
>
> Would it be possible to enhance display such that incoming input would
> abort the current display operation?

How would Emacs figure out just how much "a screenful" of text is when
it is not allowed to lay out the screen?  Where is PageDown going to end
up?

One possible way to deal with this is not to read characters while
redisplay is being processed: a reasonably well-programmed input stack
will throttle autorepeat while it has unconsumed characters.

Of course, that may not be feasible depending on how Emacs does C-g
processing.

-- 
David Kastrup