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

Reading through Koji and Florian's messages, they appear to be agreeing
with fantasai's proposed revision:

> Thinking about this some more, though, I think what we can do
> is move *both* orientations into the writing-mode, like this:
>
>    writing-mode: horizontal-tb | vertical-rl | vertical-lr | sideways-rl
| sideways-lr;
>    text-orientation: mixed | upright | sideways (or sideways-rl)
>
> This preserves symmetry, and actually makes it even easier for
> horizontal-script authors to get the two most common behaviors.
> They no longer need to use 'text-orientation' unless they want,
> specifically, upright text. So we have these cases then:

This is super confusing for authors I think. You're effectively making
'writing-mode' a pseudo-shorthand because it will need to override
'text-orientation' values, but only sometimes (i.e. the sideways-xxx
cases). You're introducing all sorts of odd combinations:

  writing-mode: sideways-rl;
  text-orientation: mixed; /* it's not really mixed anymore? */

  writing-mode: sideways-lr;
  text-orientation: upright; /* one of the values has to take precedence */

The most common use case for vertical text is CJK authoring. For that
authors really only need to use 'writing-mode', since the default value
of text-orientation will work most of the time:

  /* text-orientation defaults to mixed so doesn't need to be set */
  writing-mode: vertical-rl;

Only when overriding the default orientation does a CJK author need to
worry about setting 'text-orientation' explicitly.

I feel strongly that the complexity of other use cases, vertical
captions, vertical RTL or Ogham should be handled by 'text-orientation'
values. I also think dealing with these use cases should be the subject
of a next-level spec, not this one. We need to achieve simple interop
for the common CJK case first.

Regards,
​
John Daggett