Re: Tick Reduction

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: emacs-devel@gnu.org,  stefankangas@gmail.com,  dgutov@yandex.ru
> Date: Sun, 21 Nov 2021 21:10:29 +0100
> 
> @item :relative-width @var{factor}
> Specifies that the width of the stretch should be computed from the
> first character in the group of consecutive characters that have the
> same @code{display} property.  The space width is the pixel width of
> that character, multiplied by @var{factor}.  (On text-mode terminals,
> the ``pixel width'' of a character is usually 1, but it could be more
> for TABs and double-width CJK characters.)
> 
> :relative-width is used only one place in our code base, and I'm not
> quite sure what it's trying to achieve there, either.
> 
> The doc string here seems to be saying something about a series of
> characters, but the one usage we have only puts it on a single
> character, apparently?

This is a 'display' text property, right?  It is placed on text;
instead of that text Emacs will display a stretch glyph (white space)
whose width is calculated as the pixel width of the first character
"covered" by the property multiplied by FACTOR.