Re: right aligning a string, using display (space :align-to

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 20 Oct 2023 22:05:40 +0200
> From: martianhiatus@riseup.net
> 
> (pls cc me so i can easily respond / quote)

That's not how newsgroups work: the response goes to the newsgroup.

> > You assume that string-pixel-width takes text-scaling into account?  I
> > don't think it does; you should use window-text-pixel-size or
> > buffer-text-pixel-size instead.  That's because text-scaling is a
> > buffer-local feature, and string-pixel-width is not told which buffer
> > you have in mind.
> 
> I'm just asking for any help i can get regarding how to right-align a string in a way that isn't broken by text-scaling. i don't know how to go about it.
> 
> i'm only using string-pixel-width because i thought i needed to subtract it from "right" in the pixel-width spec, as quoted previously. i don't see how the window or buffer functions can help with that that, as i'd have to subtract my string's pixel width from them, so they'd need to replace "right", rather than my string width calculation, it seems to me. perhaps you had in mind another way to use them, but didn't say.

You didn't say enough about your code for me to know that
window-text-pixel-size is not going to help.  If so, another
possibility is to multiply the value returned by string-pixel-width by
the ratio

  (/ (float (default-font-width)) (frame-char-width))

which should scale the string width according to text-scale-mode.