Re: min-width display property, but with padding at the start

[Spencer Baugh <sbaugh@janestreet.com>]

Eli Zaretskii <eliz@gnu.org> writes:
>> From: Spencer Baugh <sbaugh@janestreet.com>
>> Date: Mon, 19 Aug 2024 16:53:58 -0400
>> 
>> 
>> I'm writing a mode which adds an entry to the mode-line containing a
>> number.  This number can rapidly grow or shrink (it's a number of build
>> targets left to build, for a build system like Bazel) so I would like to
>> pad it to a specified width, to avoid the mode-line jittering around as
>> the number changes.
>> 
>> Adding a `display' property with the value '(min-width (5.0)) works
>> fine.
>> 
>> However, min-width pads by adding padding at the end.  I'd like to add
>> padding at the start instead.
>> 
>> Is there a way to achieve this with display properties?
>
> Why do you need display properties?  What's wrong with
>
>   (format "%5s" THE-STRING)
>
> ?

That is probably what I'll do if I can't find another solution, but
doing it with display properties works with non-fixed-width characters
and faces, which a user might have configured.

If simply padding with spaces sufficed, the display properties in
(info "(elisp) Specified Space") would have little reason to exist.