Bug 271048 – Font fallback should allow selection of a Nastaliq font

• Component: Layout and Rendering
• Status: NEW

[r12a]

Interactive test, font-family:generic(nastaliq) will apply a nastaliq font in Urdu
https://github.com/w3c/character_phrase_tests/issues/63



This issue is applicable to Urdu, Kashmiri, and other Arabic script orthographies.

Languages such as Urdu and Kashmiri are written in a nastaliq style of Arabic, and authors will typically want any font fallback to select another nastaliq font, rather than a naskh or other font.

More:

- Arabic & Persian Layout Requirements (https://www.w3.org/TR/alreq/#h_writing_styles)
- Urdu (Nastaliq Arabic) Orthography Notes/Font styles (https://r12a.github.io/scripts/arab/ur.html#writing_styles)
- Nastaliq system fonts (https://r12a.github.io/scripts/fontlist/index.html?script=arab#nastaliq)

The GAP

Currently there is no way to tell the browser to fall back to a nastaliq font, rather than a naskh or other font.

Neither Gecko, Blink, nor Webkit support this. Before they can, CSS needs to provide a way for authors to indicate that a nastaliq generic font should be used.
Priority

This is a high priority for languages such as Urdu and Kashmiri, where nastaliq fonts are the norm, and incorrect substitutions may cause readability and cultural issues. It is also a useful feature for other languages, such as Persian or Kurdish, where nastaliq styles may be used for certain types of text.

The CSS Fonts 4 spec now defines (https://drafts.csswg.org/css-fonts-4/#generic-family-name-syntax) a generic(ident) syntax which will be used for newly-introduced, and especially for script-specific, generics.

generic(nastaliq) (https://drafts.csswg.org/css-fonts-4/#generic(nastaliq)-def) has been added as one of the generic family names.

This issue is being tracked by the W3C at https://github.com/w3c/alreq/issues/276

[Radar WebKit Bug Importer]

<rdar://problem/125226454>