Re: [css3-writing-modes] [CSS21] bidi of replaced inline elements

On 05/23/2011 01:32 AM, Simon Montagu wrote:
>
> I don't think anyone ever responded to my comment on an earlier version, at
> http://lists.w3.org/Archives/Public/www-style/2002Oct/0095.html:
>
> |"non-textual entities such as images are treated as neutral characters,
> |unless their 'unicode-bidi' property has a value other than 'normal', |in which case they are treated as strong characters in
> the 'direction'
> |specified for the element."
> |
> |This is not very clear. What cases are intended to have a different
> |rendering than that which would result if this phrase were omitted, and
> |the image was treated as a neutral character preceded by LRE/RLE
> |/LRO/RLO and followed by PDF?

IIRC, the rendering would be different in the case that the bidi
character's direction is different from its parent's, since in
the case of an embedding, the surrounding text is affected by its
own SOR/EOR direction and not by that of the embedded text. Right?

Although that does make me wonder if the text here is correct or
backwards. CSS2.1 has the same text.

With regards to replaced elements and their bidi behavior, there are
two cases to consider:
   - what happens when the image falls back to its alt text
   - what happens if the image is intended to represent a character
     (that is not otherwise encoded or representable)

In the first case, the element's effect on its surrounding text
should be no different whether it is rendered as replaced or as
text. In this case, we should be treating it as you say -- by
handling it with the appropriate embedding codes.

In the second case, the author might want to control the element's
effective directionality. In which case that approach won't work,
and we need to replace the character with a pretend character as
currently specified in the text.

So our options here are
   a) Take approach 1 (change the specs to use embedding codes)
   b) Take approach 2 (no change)
   c) Take approach 1 for 'embed' and approach 2 for 'bidi-override'

Thoughts?

~fantasai

Received on Monday, 23 May 2011 17:02:38 UTC