[css-writing-modes] Propose writing-mode: sideways-left

I'd like to propose:

  writing-mode: sideways-left

which is equivalent to setting the two properties:
  writing-mode: vertical-lr;
  text-orientation: sideways-left;

When this value is specified, I prefer to make the used value of
text-orientation to sideways-right, but I'm good not to if this is

Although equivalent, this proposal has following benefits.

1. Resolves dbaron's open issue where logical directions change within a BFC[1].

2. Resolves my concern of sideways-left being an inline property value
at Sydney F2F[2]. IIUC jdagett expressed the same concern before.

3. This proposal is inline with fantasai saying "we could make it
apply to blocks only" to resolve #2[2].

3. Resolves the issue where a non-at-risk value (sideways) has a
dependency on an at-risk value.

4. Eliminates a combination "vertical-rl + sideways-left" that has no
use cases and thus helps testing.

For authors, this definition is almost equivalent.

  html { text-orientation: sideways; }
  .clockwise { writing-mode: vertical-rl; }
  .counterclockwise { writing-mode: vertical-lr; }

This proposal:
  html { text-orientation: sideways-right; }
  .clockwise { writing-mode: vertical-rl; }
  .counterclockwise { writing-mode: sideways-left; }

The only downside I can think of is that we found a printed material
where RTL text within CJK vertical flow was rotated. This is still
possible by inline-block with writing-mode: sideways-left or
transform: rotate(180deg), but we can no longer wrap lines within such
rotated text. This is considered to be very rare, and I'm not aware of
any such digital text yet. I think this limitation is acceptable when
considered the benefits.

Thoughts? Any other downsides I missed?

[1] https://lists.w3.org/Archives/Public/www-style/2015Apr/0026.html
[2] https://lists.w3.org/Archives/Public/www-style/2015Mar/0188.html


Received on Tuesday, 2 June 2015 19:00:30 UTC