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Re: [CSS3 Text] text-underline-position and superscript

From: Ambrose LI <ambrose.li@gmail.com>
Date: Tue, 21 Dec 2010 17:02:43 -0500
Message-ID: <AANLkTimL1Ji4yG7iR3-bQLm6UZQyQXTfJjDPZPkXJ7+b@mail.gmail.com>
To: "Belov, Charles" <Charles.Belov@sfmta.com>
Cc: www-style@w3.org
> I am running into an issue in English with regard to text that is mixed
> regular text and superscript text, where I want an unbroken underline.
> In actual practice the underline jumps up to be immediately beneath the
> superscript text.  I would hope this before-edge/after-edge could be
> applied to the anchor tag to produce such an unbroken underline.
>
> What I'm looking for is basically alphabetical following the main
> alphabetic content, that is, superscripting would be ignored for the
> positioning of the underline.  However, the "under" proposal would not
> seem to accomplish this, since it would not be immediately beneath the
> letters, but rather further beneath.
>
> Possibly there is a need for
>
> alpha-ignore-super
> The underline is aligned with the alphabetic baseline without taking
> superscript into account. In this case the underline is likely to cross
> some descenders in non-superscripted text.
>
> I realize I can style the superscripted to not show an underline --
> that's what I'm doing now -- but if there is underlined text both
> preceding and following the superscripted text, then that produces an
> undesired break in the underline.

I feel that this case is somewhat similar to what we want to happen
for CJK text. That is, there is a need to distinguish between words
that are consecutive but must be visually separated when underlined,
and a need to keep an underline in one piece no matter what its
constituent parts are. The only difference is that in Chinese we want
to semantically mark up each part individually and in this case it
seems that there is no such intention.


> And logically:
>
> alpha-conform-sub
> The underline is aligned with the alphabetic baseline.  The entire
> underline is lowered to the position that would be required by
> subscripted text, whether or not subscripted text is present in the
> current underlined text.
>
> alpha-conform-if-sub
> The underline is aligned with the alphabetic baseline.  If subscript is
> present in the underlined portion, the entire underline is lowered to
> the position required by the subscripted text.
>
> alpha-conform-line-if-sub
> The underline is aligned with the alphabetic baseline.  If subscript is
> present in an underlined portion anywhere on the current text line,
> whether or not a subscript is present in the current underlined portion,
> the entire underline is lowered to the position that would be required
> by the subscripted text were it present in the current underlined
> portion.
>
> Also, is there a reason that pixel-positioning of the underline is not
> part of this proposal?

"Pixel" (by which I mean finer-grain than above, middle, and below)
positioning would be great, since the default underline position for
Chinese (for underlines used as proper punctuation marks) often looks
wrong.



-- 
cheers,
-ambrose

does anyone know how to fix Snow Leopard? it broke input method
switching and is causing many typing mistakes and is very annoying
Received on Tuesday, 21 December 2010 22:03:11 GMT

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