[packagekit] [Fontconfig] FontConfig iso15924 tag for autoinstallation via PackageKit

[Behdad Esfahbod]

On 14-04-30 03:45 AM, Frédéric WANG wrote:
> Dear FontConfig & PackageKit developers,
> 
> I've recently worked on automatic font installation in Gecko-based
> applications using PackageKit [1]. The current patch to add notifications for
> missing glyphs in Gecko relies on script tags as defined in iso15924 [2] [3].

The problem with choosing fonts based on script tags is that it doesn't work.

Really.  Find me a font that supports script=Arab.  I don't think you can find
any font right now that supports **all** Unicode characters for Arabic
scripts.  If you did, it probably would be a junk font like GNU Unifont or
some other "quantity-over-quality" font that should be buried.

Fonts can only be meaningfully chosen per language tag, not script tag.

Fix your design.  You should resolve to a language tag given the script and
any hinted languages (HTML tags, etc).  Pango has code for that, and it's easy
to replicate.  I'd be happy to elaborate if you care.

behdad

> So it would help if fontconfig & PackageKit would be able to handle some
> metadata for these script tags, for example :script=Khmr (at the moment I
> think only the :lang tag is supported). Also, I'm interested in automatic
> installation of math fonts, so it would be important to support the code
> "Zmth=Mathematical notation" too. This script does not correspond to any
> Unicode script, but you can find some relevant ranges in
> http://www.w3.org/TR/xml-entity-names/#blocks (especially the Mathematical
> Alphanumeric Symbols are important and are required for [4])
> 
> Thanks,
> 
> [1] https://bugzilla.mozilla.org/show_bug.cgi?id=467729
> [2] http://www.unicode.org/iso15924/iso15924-codes.html
> [3] https://bugzilla.mozilla.org/show_bug.cgi?id=619521
> [4] https://bugzilla.mozilla.org/show_bug.cgi?id=930504
> 

-- 
behdad
http://behdad.org/