Forwarded message 1
> -----Original Message-----
> From: L. David Baron [mailto:dbaron@dbaron.org]
> Sent: Monday, May 12, 2008 7:41 PM
> To: Mikko Rantalainen; W. Leon Sutton, Jr.; fantasai; Adam Kuehn
> Cc: www-style@w3.org
> Subject: Re: [css3-color] RGBA Hex Notation
>
> On Thursday 2004-09-09 16:56 +0300, Mikko Rantalainen wrote:
> > Ian Hickson wrote:
> >> On Thu, 2 Sep 2004, Brian Hunger wrote:
> >>> alpha!
> >>
> >> http://www.w3.org/TR/css3-color/#rgba-color
> >> Already supported by Safari.
> >
> > Why not support #1234 and #12345678 formats too? The RGB
> color syntax
> > already supports #123 and #123456
> > <URL:http://www.w3.org/TR/css3-color/#rgb-color>. A new
> syntax with 4 or
> > 8 digits wouldn't collide with the old mechanism, instead
> it would be a
> > logical extension.
> >
> > For example, #7777 would be 50% transparent 50% grey, #f004
> would be
> > ~25% opaque red etc. The short forms would be expanded just
> like RGB
> > values: double the digits. The above examples would be equal to
> > #77777777 and #ff000044 or rgba(127,127,127,127) and
> rgba(255,0,0,68)
>
> The working group discussed the addition of new features to
> css3-color and decided that no new features should be added at this
> time; rather, the draft should be advanced with its current feature
> set, which is at this point widely implemented. New features will
> be considered for the next level of the CSS color module.
>
> If you are not satisfied with this response, please let us know
> within two weeks, if possible.
>
> -David
Personally, I think this is a mistake.
First, it isn't really the addition of a full-blown "feature". RGBA is
already the specified feature. This suggestion adds only a notational
convention to access the feature.
Second, the reason for making the addition is clear: By far the most popular
notational form for color in use on actual web pages at present is
hexadecimal. You will get much broader user acceptance of the spec if you
support a reasonable extension of this format for RGBA. I would suggest
that a hex notation format for RGBA at least be specified, even if it is
indicated as optional for implementers. At least that would standardize the
target notation for future use.
Finally, implementation of a hex notation, whatever the agreed format,
should be completely trivial. Parsers are just not that hard to write when
the input format is clearly specified and inflexible. The code for
producing the actual color is already there for use, as you just explained
("current feature set...is...widely implemented").
Personally, I would use #XXX-A and #XXXXXX-A for the format, but it doesn't
really matter as long as it is reasonable to users and is standardized. A
little work now can make a difficult spec just that much easier for web
developers to internalize.
Respectfully submitted,
-Adam Kuehn
>
> On Thursday 2004-09-09 21:17 -0400, W. Leon Sutton, Jr. wrote (in
> response to the previous quoted message):
> > Yes, the RGB-A color format would be a great addition.
> There are many uses
> > for such that I can think of.
>
> On Friday 2004-09-10 10:39 -0400, Adam Kuehn wrote (in response to
> the previous quoted message):
> > Let's be clear that rgba color *format* is already in the
> CSS 3 Color
> > Module CR draft. The current draft includes rgba (xxx, xxx, xxx,
> > <alpha>) and rgba (xxx%,xxx%, xxx%, <alpha>) as the only
> two available
> > notational forms to express that color format. My
> suggestion is to add a
> > hex notation form to those already proposed. E.g. color:
> #xxx<alpha> and
> > color: #xxxxxx<alpha> - either with or without a delimiter
> before the
> > <alpha> portion. The reason for the suggestion is to
> preserve the most
> > common color notation format presently in use in CSS when
> used for alpha
> > colors. In my view, it is worth the effort to make the use of the
> > property as easy for current and future authors as possible.
>
> --
> L. David Baron http://dbaron.org/
> Mozilla Corporation http://www.mozilla.com/
>