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

Reply inline.
> On Jun 30, 2015, at 10:39 PM, Koji Ishii <kojiishi@gmail.com> wrote:
> 
> On Tue, Jun 30, 2015 at 3:58 AM, Myles C. Maxfield <mmaxfield@apple.com <mailto:mmaxfield@apple.com>> wrote:
> [snip]
> The cases I'm trying to guard against are things like:
> "left right"
> "auto under"
> "left left right left"
> Understood. Then your proposal is identical to Masayuki's.
> 
>> Also there's a text saying "If left or right is specified alone, under is also implied", not explicitly written but I think Masayuki implied to change this too by the syntax change.
>>  
>> and removing the text-underline-position sections of the recommended default UA stylesheet.
>> 
>> Even after the change to the syntax was made?
> 
> Yes, please see my argument regarding how this language-specific logic should be implemented by "auto" rather than the default UA stylesheet.
> 
> Clarification appreciated since your arguments could read in two ways; I understand you want "auto" to do proper positioning between Latin and under. Are you also suggesting, when just "auto" is specified, it should set "right" (almost 100% for JK) and "left" (almost 100% for C if emphasis purposes IIUC)?

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"
"auto left" would mean "For vertical writing modes, put the underline on the left. Otherwise, it's up to you."
"under left" would mean "For horizontal writing modes, use the 'under' underline. Otherwise, (for vertical writing modes), put the underline on the left"
"under" would mean "For horizontal writing modes, use the 'under' underline. Otherwise, do whatever you think is best"
"left" is the same as "auto left"

What are your thoughts?

> 
> I can then understand your proposal is about moving UA stylesheet rules to the logic.
> 
> If you're suggesting "auto" does automatic only for horizontal flow, I can understand your proposal is not to mention any automatic behavior for vertical flow even informally.
> 
> Which is your intention?
> 
> /koji