Re: [css-text-decor] Doesn't example 3 in text-underline-position break current UA behavior?

On 01/25/2016 06:58 AM, Koji Ishii wrote:
>
> On Fri, Jul 3, 2015 at 2:12 AM, Myles C. Maxfield wrote:
>>
>> I'm proposing that "auto" should take any and all context
>>into consideration, including things like which language the
>> text seems to have come from, how many characters in a row
>>seem to come from that language, where line breaks occur, etc.
>> Given all this information, "auto" can decide whether to put
>>the line on the left or the right, and it can make this
>> decision on whatever granularity makes the most sense
>>(character, phrase, line, element, etc.). I'm also proposing
>> that this behavior be able to be overridden using "under",
>>"left", or "right".
>>
>> "auto" would mean "Do whatever you think is best"
>
> I still agree on this. For this to work, we need two edits to the spec:
> 1. Remove the UA stylesheet rules and let UA to figure out whatever
>  if "auto".
> 2. Remove "however it must be placed at or under the alphabetic
>  baseline" from "auto" since it prohibits placing on right in
>    vertical flow.

The problem with this is that we no longer have an option that
indicates a preference for alphabetic underlining in vertical
text. When it's specified through the UA style sheet, the author
still retains such control. If it's incorporated into auto, the
author can no longer override the side-switching behavior.

If the WG believes that moving language-based logic to the initial
value is better, then we need a new value to represent the current
meaning of 'auto'.

>> "under" would mean "For horizontal writing modes, use the 'under'
>> underline. Otherwise, do whatever you think is best"
>
> I agree on this. "right" and "left" can imply "under", but the opposite
> isn't true; "under" could be "left" (accounting or Chinese) or "right"
> (Japanese or Korean.)

I disagree strongly with this. The 'under' option is explicitly for
placing the line on the "under" side of the text, regardless of language.
It should retain this semantic.

> So now my proposal is above 1 and 2, and:
> 3. Clarify when "under" alone is used, its position in vertical flow
>  is automatic (the behavior isn't defined today.)
> 4. The value syntax could be one of:
>   a. No change: auto | [ under || [ left | right ] ]
>   b. Full options: auto | [ under || [ left | right | auto ]]
>   c. Simpler: auto | under | left | right
>
> I prefer "simple and good enough for now, extend in future" option, so "c".

I don't mind to simplify the syntax, but I disagree strongly with #3.

~fantasai

Received on Friday, 23 December 2016 06:21:36 UTC