Re: [css3-writing-modes] Request to publish Last Call Working Draft

On 24/05/2011 2:29 AM, fantasai wrote:
> On 05/23/2011 02:29 AM, Alan Gresley wrote:
>>
>> Why does the draft spec avoid start and end values. I know that 'beas'
>> didn't quite work but I do believe in is safe to use start and end
>> values for margin, border, padding and text-align on both inline-level
>> and block-level elements.
>
> The CSSWG resolved not to introduce logical properties for margin, border,
> and padding in this draft.
>
> 'text-align: start' is covered in CSS3 Text.
>
> ~fantasai


I understand what the CSSWG resolved but logical properties only came 
into crises since logical values for before and after in vertical 
Mongolian-based writing mode did not make sense when it's block flow 
direction is 180 degree different to it's line orientation of the glyphs.

There are still line-relative directions such as line left and line 
right. These are logical ways of understanding vertical writing mode, in 
both cases (CJK and Mongolian), the line-left is to the start side and 
line-right is to the end side of the inline base direction. Logical 
values for start and end have no great benefit in horizontal 
bidirectional text (LTR with RTL or visa verso) but they have a huge 
benefit in vertical text. A width (logical) is easy conceptualized as 
height (measure) since you only swapping the x and y axises but left and 
right run along these axises.

Are you expecting authors of CJK and Mongolian to tilt there head 
towards the right until they mentally perceived left as the start side 
and right as the end side. Do authors of horizontal text have to do 
something similar?


-- 
Alan Gresley
http://css-3d.org/
http://css-class.com/

Received on Friday, 27 May 2011 17:37:05 UTC