[css-writing-modes] text-orientation: sideways-left

I'd like to propose to:
1. Defer 'sideways-left'[1] to Level 4, and
2. Make 'sideways' as a value alias to 'sideways-right', not as a
switch between 'sideways-left' and 'sideways-right' by writing-mode.

Currently, WebKit and Blink does not implement this value, and do #2
above. IE does not implement this property yet. I don't know the
status of Gecko, but I'd like to sort this out before implementations
pick different choices for the 'sideways' value.

Currently the property is prefixed, so we could probably work out if
truly needed, but I hear no complaints with the current WebKit/Blink
implementations.

One more thing to note on this value is that, a concern was raised
before that all other values of this property only change orientation
of characters, while this value changes the baseline as well. This
difference makes implementing this value more complex than others.
IIRC the discussion didn't last long, but I think it was not really
satisfactory for the proposer.

Other 3 values (mixed, upright, and sideways-right) are important for
Chinese and Japanese vertical flow, while this value is for rarer use
cases in other scripts. I propose that this value can be discussed
further in Level 4, and I wish us not to introduce interoperability
issues nor slow this spec down because of this value.

[1] http://dev.w3.org/csswg/css-writing-modes-3/#valdef-text-orientation-sideways-left

/koji

Received on Sunday, 11 January 2015 15:27:19 UTC