Re: [css-figures] Re: [css-writing-modes] the caption-side keywords

Håkon Wium Lie <howcome@opera.com> wrote on 2014/03/18 3:25:01
> MURAKAMI-san wrote:
> 
>  > BTW, the 'float' property will have same problem when 'top' and 'bottom' 
>  > (or 'block-start' and 'block-end') values are added.
>  > I discussed with Håkon about this.
>  > His idea is 'top' = 'block-start' (aliases). See:
>  > http://figures.spec.whatwg.org/#floating-to-the-top-bottom:-float
> 
> Yes, 'block-start' and 'block-end' seems like viable alternatives. If
> so, do we also need 'before' and 'after' as aliases? Although the cost
> of an alias is quite low, there is still a cost.

I think that once the Abstract Box Terminology is defined 
in CSS Writing Modes, all CSS specifications have to use this
terminology, so 'block-start' and 'block-end' (not 'top'/'bottom') 
would be the primary keywords for block axis alignment, 
and aliases would be defined for convenience.

The 'before' and 'after' are old names of 'block-start' and 'block-end',
although they are still remained in some CSS drafts, for example:
http://dev.w3.org/csswg/css-position/#logical-box-offsets-beaso
    Logical box offsets: ‘offset-before’, ‘offset-end’, ‘offset-after’,
    ‘offset-start’, and ‘offset’
I believe these will be changed soon.

We (Antenna House) support 'before' and 'after' because they are
defined in XSL-FO; our implementation (Antenna House Formatter) 
supports both CSS and XSL stylesheet languages.
We will continue supporting 'before' and 'after' for compatibility,
but I don't think CSS modules should define these as aliases of
'block-start' and 'block-end'.

> 
> One issue may be with the 'top-bottom' and 'bottom-top' keywords
> (which were added in response to a use case described in [1]). If we
> simply expand the keywords, we would get:
> 
>   top-bottom = block-start-block-end
>   bottom-top = block-end-block-start
> 
> Which is longer, and perhaps not so intuitive.
> 
> [1] http://lists.w3.org/Archives/Public/www-style/2013Sep/0419.html

I prefer block-start-end/block-end-start.
When block/inline are obvious or duplicate they can be omitted.
Also 'block-start-inline-end' (= top-right in horizontal ltr writing mode),
etc. also make sense.


Regards,

Shinyu Murakami
Antenna House

Received on Tuesday, 18 March 2014 03:23:39 UTC