Re: Proposal to improve the nomenclature of scrolling directions

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 10 Nov 2012 12:09:59 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: rms@gnu.org, dan@haxney.org, eli@barzilay.org, emacs-devel@gnu.org, 
>  nix@esperi.org.uk, monnier@iro.umontreal.ca, dmoncayo@gmail.com, 
>  stephen@xemacs.org
> 
>  > Meanwhile, it turned out that what's requested is something else: when
>  > the user or a Lisp program deliberately scrolls the text, leave point
>  > where it was, instead of moving it to be visible in the new contents
>  > of the window.  This would need changes to window-scrolling code in
>  > window.c, to avoid moving point.
> 
> Not necessarily.  We can always move point lazily, that is, whenever it
> is requested.

That requires changes to window-scrolling functions, since currently
they do move point, and they do it non-lazily.  See
window_scroll_pixel_based, where it calls SET_PT_BOTH etc.

And what does "whenever it is requested" means, anyway, in practical
terms?  Those "other editors" that allow point to stay out of the
window will scroll the display back to show point when some command is
invoked that modifies the buffer text.  Given that the modification
commands don't require moving point, and C-v/M-v won't either (as this
is the main justification for the feature we are discussing), what
will?

> As long as scrolling proceeds, we can pretend (visually) that it's
> somewhere else.

You are describing the kludgey solution (IIUC), whereas I'm suggesting
a non-kludgey one.