Re: [css-writing-modes] 'direction' vs. vertical text

On 05/07/2014 09:31 AM, Simon Sapin wrote:
> On 07/05/2014 17:27, Tab Atkins Jr. wrote:
>> On Wed, May 7, 2014 at 7:59 AM, Simon Sapin <simon.sapin@exyr.org> wrote:
>>> In "Introduction to Writing Modes", the inline base direction is defined
>>> such that it exists in all writing modes. However, the current definition of
>>> the 'direction' property seems to assume an horizontal writing mode:
>>>
>>>> Values for this property have the following meanings:
>>>>
>>>> ltr
>>>>      Left-to-right directionality.
>>>> rtl
>>>>      Right-to-left directionality.
>>>
>>> What do these values mean for vertical text?

These are about bidi. They don't give the inline direction directly.
If I turn the text upside down with transforms, LTR goes from right
to left. You're not confused about that, right? :)

>>> Should they map to top-down and bottom-up respectively, or should the
>>> inline-start direction always be up, or something else?
>>>
>>> (This may be defined in another part of the spec that I haven’t read yet,
>>> but it should at least be linked from here, if not defined here.)
>>
>> It could perhaps be clarified that it refers to line-left to
>> line-right directionality, etc.  (Those are the line-relative
>> directions.)
>
> I was gonna reply "sounds fine, with the terms appropriately linked/
> cross-referenced", but the definition of these terms seems to be
> based on 'direction' so I still don’t know what they mean in a
> vertical writing mode :)
>
>> line-left
>>     Nominally the side from which LTR text would start.
>> line-right
>>     Nominally the side from which RTL text would start. (Opposite of line-left.)

Keep reading, there's a nice diagram right below.
   http://dev.w3.org/csswg/css-writing-modes/#line-directions
And a table if you want it all laid out for you:
   http://dev.w3.org/csswg/css-writing-modes/#logical-to-physical

I agree there could be some clarifications, though.

~fantasai

Received on Wednesday, 7 May 2014 16:43:02 UTC