[css3-text] Proposal for text decoration blink value

Hi all,

I am implementing the CSS3 text decoration support on WebKit, based on
the latest Editor's Draft for CSS Text Level 3 (
http://dev.w3.org/csswg/css3-text/ ).

Said this, I am going to suggest a change on the CSS3 specification of
"text-decoration", related to the "blink" value. But first, we need to
ask ourselves if this is really needed, it seems that only Firefox and
Opera implements this, and to not implement it satisfies the
checkpoint 3.3 of WAI-UAAG (
http://www.w3.org/TR/UAAG/guidelines.html#tech-on-off-blinking-text ).
I imagine two scenarios for this:

1. Abolish usage of "blink" value, since the same behavior is
achievable with rgba() alpha animation.

2. Make "blink" value become a bitwise property value for
"text-decoration-line", thus modifying "text-decoration" to the
acceptable values below:
"text-decoration" values: <text-decoration-line> ||
<text-decoration-style> || <text-decoration-color>
"text-decoration-line" values: none | [ underline || overline ||
line-through || blink ]

3. Make "blink" become a shorthand, not just a valid value inside
"text-decoration" property, so "text-property" acceptable values
become like this:
"text-decoration" values: <text-decoration-line> ||
<text-decoration-style> || <text-decoration-color> ||
<text-decoration-blink>

The new property shorthand would have the following specification:
Name: text-decoration-blink
Value: fixed | blink
Initial: fixed
Applies to: all elements
Inherited: no
Percentages: N/A
Media: visual
Computed value: as specified

----

The scenario (1) does not seem to be viable because AFAIK we need to
provide proper backwards compatibility with previous CSS
specifications.
Scenario (2) is the most simple to implement, though we need to check
if makes sense to have "blink" feature attached to text decoration
line specification.
Scenario (3) is also simple to implement, and also maintains backwards
compatibility with previous CSS 2.1 specification for text decoration.

IMO I feel comfortable with scenario (3), where we can even extend
this usage to satisfy text blinking details like period between
blinks, for example.

I kindly ask for feedbacks and comments on this proposal, thanks in advance!

-- 
Bruno de Oliveira Abinader

Received on Sunday, 5 August 2012 21:22:51 UTC