Re: [css-fonts] "system" generic font name

Myles Maxfield wrote:

> CSS describes a collection of “generic” font families. We propose
> adding a new generic font family, “system,” which will be backed by
> whichever font is the native UI font of the platform running the
> browser. Specifically, we are proposing that this new generic font
> family be platform-specific, and not browser-specific, so the same
> browser running on different operating systems will implement this
> generic font family differently.

This sounds fine to me. I think the other system UI font values of the
'font' property are a bit of a failed experiment. Different user
interfaces use different typographic systems so it's difficult to map
those onto a common set of system font keywords that work consistently
across devices/platforms. But I think having a generic font-family name
that maps to the default UI font family would be easy to define in a
consistent way.

Other generics are generally content-locale sensitive and I think a
'system' generic should be also. So content marked as lang="ja",
font-family: system within an English UI would use the *Japanese* UI
font rather than the English one. This is inline with how generics are
generally implemented and different from how the system font values work.

Note that this is different from the "default content font" which user
agents typically map for Latin-script locales to a serif font family.
Non-Latin-script locales sometimes map to sans-serif, depending upon the
common usage for a given locale. Most font API's have some way to query
for the UI font. Under Linux for example, a GTK call would be used
rather than a simple fontconfig query.

Regards,

John Daggett
Mozilla Japan

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