Re: WebVTT bidi: should a cue be allowed to contain more than one paragraph?

On Fri, 27 Apr 2012, Silvia Pfeiffer wrote:
> On Fri, Apr 27, 2012 at 6:32 AM, Ian Hickson <ian@hixie.ch> wrote:
> > On Thu, 26 Apr 2012, Aharon (Vladimir) Lanin wrote:
> >>
> >> Thanks, this is great!
> >>
> >> One thing, though. As far as I can see, the WebVTT spec does not say 
> >> that the cue is supposed to be *rendered* in accordance with the 
> >> Unicode bidi algorithm, and more specifically that its P3 (i.e. first 
> >> strong character) determines each paragraph's base direction. 
> >> (Currently, the spec mentions the bidi algorithm's paragraph level 
> >> steps effectively just for the purpose of resolving cue alignment. It 
> >> does not say anything about the rendering, i.e. visual ordering of 
> >> the characters.) The bidi algorithm allows higher level protocols to 
> >> override P3, as is the case almost everywhere in HTML, for example. 
> >> It is important that implementers realize that in WebVTT there is no 
> >> higher level protocol, and thus P3 should apply, and (bidi-aware) 
> >> users know what to expect and how they can make use of it.
> >
> > The rendering is defined in terms of CSS. CSS is the higher level 
> > protocol and it is CSS that then invokes the bidi algorithm for 
> > layout.
> 
> Isn't that only true when we are rendering in the browser?

The rendering is always defined by CSS; what changes is just whether it's 
possible to provide any CSS sheets to affect this. (In the cases where 
it's not, it's far easier to implement, naturally; the semantics still 
have to match CSS, though, just with only the values given in the spec.)

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

Received on Friday, 27 April 2012 15:21:07 UTC