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

On Thu, Dec 11, 2014 at 9:36 AM, Daniel Holbert <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
> (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.)
>

Actually, I hope the answer is yes. I'm not quite sure which way is better,
but we have had some style fixup like this, and I don't think it's a big
problem to add one more rule there. The only problem might be that it would
add memory footprint.

I feel that, if we don't do this, we need to maintain another path for this
value, and handle inheritance ourselves.


>  (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?
>

If that is style fixup, then it certainly only influences elements with
"display: ruby-text-container", since ruby-position is inherited by
default, and author may specify it in an outer container.

- Xidorn