Re: emacs-27 60c84ad: ; * etc/TODO: Fix last change.

[Eli Zaretskii <eliz@gnu.org>]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: monnier@iro.umontreal.ca,  emacs-devel@gnu.org
> Date: Thu, 05 Mar 2020 17:08:12 +0100
> 
> >>>>> On Thu, 05 Mar 2020 17:24:01 +0200, Eli Zaretskii <eliz@gnu.org> said:
> 
>     Eli> I don't think it has little to do with the Unicode idea, it just
>     Eli> doesn't use the database.  The blocks I was talking about are all
>     Eli> Emoji blocks, and Unicode is generally careful to put related
>     Eli> characters into the same blocks.
> 
> If you look at the list of Emoji codepoints I sent earlier, I think
> you'll agree that they're all over the place. But at least this makes
> the patch smaller :-)

Yes.  And I think the Emoji that are outside of those 4 blocks are of
the kind that by default display in their text presentation, isn't
that right?

> Note that with this, and Symbola disabled, this does not display a
> glyph for U+1F300 on macOS unless I prepend 'Apple Color Emoji' to the
> frame's fontset. Is that expected on macOS?

I'm not familiar with how Emacs on macOS looks for fonts, sorry.  On
Windows, we will need the help of w32-find-non-USB-fonts to find the
built-in fonts for Emoji (because there are no Unicode sub-range bits
for Emoji), if Noto Color Emoji is not installed, so maybe something
similar is needed on macOS.  Maybe Yamamoto-san (CC'ed) can chime in
and help us here.

> -    else if (name ~ /punctuation|mathematical|arrows|currency|superscript|small form variants|geometric|dingbats|enclosed|alchemical|pictograph|emoticon|transport/) return "symbol"
> +    else if (name ~ /transport|supplemental symbols/) return "emoji"
> +    else if (name ~ /punctuation|mathematical|arrows|currency|superscript|small form variants|geometric|dingbats|enclosed|alchemical|pictograph/) return "symbol"

I think we should also convert "variation selectors" to "emoji".  We
must have the same font selected for variation selectors and for the
emoticons, otherwise character composition will not work.

> +        (emoji #x1F300)))

I think we should add at least #x1F600 and #xFE0F as representative
characters for 'emoji'.

> +  (set-fontset-font "fontset-default" 'emoji
> +                      "Noto Color Emoji" nil 'prepend)

I think it's better to use '("Noto Color Emoji" . "iso10646-1")
instead of just the family name, for consistency if nothing else.

Thanks.