Re: The unwarranted scrolling assumption

[David Engster]

Eli Zaretskii writes:
>> From: Lennart Borgman <address@hidden>
>> Date: Thu, 17 Jun 2010 21:10:55 +0200
>> Cc: address@hidden, address@hidden
>> 
>> > Please show a recipe starting from "emacs -Q".
>> 
>> I am sorry, I thought that was clear. Just open a large C file for
>> example, like window.c. Set the variables as suggested earlier in this
>> thread that should prevent "jumping scrolling".
>> 
>> Then just hold down or rapidly press the down arrow. You will see (if
>> your pc is not too fast) that Emacs does the "jumping scrolling" now
>> and then. Not every time, but now and then, probably when it gets
>> behind in screen updating.
>
> It doesn't jump for me.  And, if the machine is too slow and cannot
> keep up with the keyboard's autorepeat rate, then what's wrong with
> the "jumps"?  What would you want Emacs to do instead, if it cannot
> keep up with the input?

Well, you got a point there. I remember that for some time I simply used
something like

(global-set-key (kbd "<down>")
                  (lambda () (interactive)
                    (progn (next-line) (redisplay t))))

which also prevents the jumping. But obviously, if you do that, Emacs
will start to lag behind the input, so that it continues scrolling even
when you're no longer pressing the key, which is worse than jumping.

What I would like is that the input is somehow limited to Emacs'
speed, but maybe this simply isn't possible?

-David