Re: [css-ruby] What does it mean for "ruby-position: inter-character" to force writing-mode to be vertical?

> Personally, I think it bad design to have a value of ruby-position indirectly mutate writing-mode. IMO, it would be better to do nothing, and simply ignore that value (or use a default) if writing mode isn't already vertical.

I think "ruby-position: inter-character" is for Bopomofo ruby and the value do great help for layout in horizontal writing to make sure bopomofo ruby placed in the right of Hanzi, and do not separated by line-break. [1]
   
 And the specification may trace back to 1999[2]. If you have any better solution or suggestion, please let me know.

[1] http://www.slideshare.net/bobby3302/bopomobo-ruby
[2] http://www.w3.org/TR/1999/WD-i18n-format-19990910/


Bobby Tung


> Glenn Adams <glenn@skynav.com> 於 2014年12月14日 下午11:36 寫道：
> 
> 
> On Wed, Dec 10, 2014 at 3:36 PM, Daniel Holbert <dholbert@mozilla.com <mailto:dholbert@mozilla.com>> wrote:
> The CSS Ruby spec has the following text about ruby-position's
> "inter-character" value:
> 
>   # "inter-character"
>   #   [...] This value forces the 'writing-mode' of the
>   #   ruby annotation to be vertical.
> http://dev.w3.org/csswg/css-ruby/#valdef-ruby-position-inter-character <http://dev.w3.org/csswg/css-ruby/#valdef-ruby-position-inter-character>
> (Note: 'writing-mode' is a link to the definition of that CSS property.)
> 
> This spec text needs some clarification, I think. In particular, the
> following things are unclear to me:
> 
>  (1) Does this spec-text influence the *computed value* of the
> 'writing-mode' property? (I hope not; there's added complexity when
> properties influence other properties' computed values on the same element.)
> 
>  (2) If the answer to (1) is "yes" (I hope not): is this "writing-mode"
> computed-value influence restricted to elements with "display:
> ruby-text", or does this influence happen regardless of "display"?  e.g.
> would <div style="display:block; ruby-position: inter-character"> be
> forced to have a vertical writing-mode?
> 
>  (3) Which 'writing-mode' value should we actually use?  There are two
> distinct vertical values for the "writing-mode" property: "vertical-rl"
> and "vertical-lr" -- which of those should we use here?  (In practice,
> maybe it doesn't matter, because elsewhere the spec says "There are no
> line breaking opportunities within inter-character annotations", and I
> think the "rl" vs. "lr" distinction would only matter if there are
> linebreaks. Still -- we should explicitly mention that here,
> particularly if we're linkifying 'writing-mode' to point to the
> property-definition, because otherwise it just seems vague.)
> 
>  (4) Does this "forcing" apply to descendants of the ruby annotation?
> e.g. if a ruby annotation has a child with "display:inline-block", is
> that child *also* forced to have a vertical writing-mode?  (If the child
> isn't forced: does it still get a vertical writing mode by default,
> somehow? Presumably not through inheritance, unless the answer to (1)
> was "yes".)
> 
> Thanks,
> ~Daniel
>