Re: [css3-text-layout] margin-before/after/start/end etc. and :ttb pseudo-classes

On 06/06/2010 04:25 PM, Håkon Wium Lie wrote:
> Also sprach Brad Kemper:
>   >  >  That would be a longer stretch, but not impossibly so. Code like this
>   >  >  could work:
>   >  >
>   >  >  @media (block-direction: rl) { ... }
>   >  >  @media (preferred-writing-mode: vertical) { ... }
>   >  >  @media (ttb) { ... }
>   >
>   >  Why a longer stretch? It would be better than writing ':ttb' a hundred
>   >  times.
> I'm fine with using media queries. Querying user preferences would be
> somewhat novel, but one can query window sizes today and that is also
> a user preference, kind of.

We're also planning to extend media queries to handle accessibility
queries, I guess this is just going in yet another direction. :)

> Perhaps:
>    @media (rtl) { ... }
>    @media (ltr) { ... }
>    @media (ttb) { ... }

rtl vs ltr is not really a user preference. The inline progression direction
is script-determined, so ltr-vs.rtl and ttb-vs-btt are not useful distinctions
here. It's not the inline direction we care about here, it's just horizontal
writing vs. vertical writing, e.g.
   preferred-writing-mode: vertical
   preferred-writing-mode: horizontal

We'd probably also want a don't-care option, e.g.
   preferred-writing-mode: auto /* no preference indicated */

Note: A block direction that is bottom-to-top (vs top-to-bottom, like in
normal English) is pretty rare and while we might have the option to
specify bottom-to-top in CSS, it's not useful to have a user preference
to distinguish the two. And as for vertical writing modes, left-to-right
vs. right-to-left is strongly writing-system-dependent, with CJK scripts
going right-to-left and Mongolian-related systems going left-to-right.
So distinguishing those in the prefs is not useful either. The main thing
to consider is whether we are writing horizontally or vertically.


Received on Monday, 7 June 2010 00:19:42 UTC