Re: [CSS21][css3-text] letter-spacing, word-spacing and justification

On 05/10/2013 07:17 PM, fantasai wrote:
>
> Our proposal...

Steve Zilles asked for proposed text for these...

> Part I: letter-spacing: <length> allows justification
>
>    This solves backwards-compatibility with such style sheets as you mention,
>    and is also consistent with implementations.
>
>    It is also consistent with how 'word-spacing' behaves: <length> values
>    there allow justification.
>
>    (Note: This would be a change from CSS2.1, so will need to be backported.)

Proposed text, added to 'letter-spacing' section;

  | Depending on the justification rules in effect, user agents may
  | further increase or decrease the space between characters
  | in order to justify text. See 'text-justify' for details.

> Part II: Add 'fixed' keyword to disallow justification
>
>    We have a problem if we allow justification for letter-spacing always;
>    German typesetting rules requires that it not be allowed! So here is
>    a proposal --
>
>      letter-spacing: normal | <length> || fixed
>
>    If 'fixed' keyword is specified, then justification cannot alter
>    letter-spacing, only word-spacing.
>
> I think Part I is important to take. I am open to other suggestions to
> solve the use case in Part II...

Proposed text:

  | fixed
  |   When this keyword is specified, user agents must not adjust spacing
  |   between characters in order to justify text.
  |   Justification is only allowed at expansion opportunities provided by
  |   a single character (such as a word separator or other punctuation).

  | Unless the ''fixed'' keyword is specified, depending on ... [above] ...


Relatedly, I think we need to add this to the 'text-justify' section:

  | It is not defined in this level whether or how other factors
  | (such as font size, letter-spacing, glyph shape, position
  | within the line, etc.) may influence the distribution of
  | space to expansion opportunities within the line.

because while justification space is additive with tracking, I don't
think we want to define that it can't account for differences in
tracking: I'm pretty sure that adding 2px space between characters
is more noticeable with zero spacing than with 10px spacing, and
while we do want differences in letter-spacing to not be equalized
away, imo the UA should be allowed to bias justification space to
make it less noticeable.

~fantasai

Received on Tuesday, 30 July 2013 20:35:28 UTC