Subject: Re: Scrolling

From: Andrew Innes <[email-masked]>
Date: Fri, 19 Jul 1996 12:46:14 +0100

On Tue, 16 Jul 1996 10:19:14 -0400, "Thomas A. Mills" <[email-masked]> said:
>Is there a way to get NTEmacs to re-paint with every line or page or
>half-page that I scroll?  Or even with scroll-bar scrolling: dragging
>the scroll-bar button, clicking the scroll arrows, or clicking the
>between-space in the scroll bar?
>
>Currently, if I reach a certain speed in scrolling, NTEmacs stops
>repainting until I've stopped scrolling.  It makes it go much faster,
>I'm sure.  But sometimes I want to see what I'm scrolling past
>especially on really huge files.

Unfortunately, this problem is not easily solved on NT - it is partly
deliberate behaviour that redisplay should be interrupted by new input
(so you can type as fast as you want without losing keystrokes, and the
display will catch up when you pause).

I'm bothered by this behaviour as well, but I haven't been able to work
out yet whether NT Emacs is doing something wrong that makes redisplay
slower than it should be, or if it is simply that Unix machines are
better able to keep up with keystrokes and scroll bar events causing
scrolling (maybe because as an X client Emacs is decoupled from the
actual drawing work of redisplay, so it completes faster).

The only thing you can do to affect the scrolling behaviour (using
scroll bars) is to increase win32-mouse-move-interval - this reduces the
frequency at which Emacs gets sent scroll bar events, giving it more
time to finish redisplay before the next event arrives.  This also
affects mouse selection of text.

AndrewI