[css3-background] 'background' shorthand

Encouraged by the discussion on embedded fonts & image replacement, the 
CSS WG asks for help on another issue:

Last year's draft of Backgrounds and Borders[1] contains an enhanced 
syntax for the 'background' property that also allows the size of the 
background image(s) to be specified.

The problem is how to distinguish the size from the position, because 
both can be expressed as lengths. In the draft, the size is therefore 
enclosed in parentheses:

    ... 1em 1em (20% 50%)...

means that the image is positioned at 1em from the left and 1em from the 
top and it has a width of 20% and a height of 50%.

That works, but parentheses aren't the most elegant kind of punctuation. 
They may be confused with expressions and once we have real 
expressions, such as expr(20% + 1em), it would look strange to have to 
write '(expr(20% + 1em))'.

So, the CSS WG wants some other syntax. The possibilities are endless, 
in theory. In practice, it requires some creativity...

Who can come up with a syntax for the 'background' shorthand that is 
unambiguous (of course!), easy to read and easy to remember?

[1] http://www.w3.org/TR/2005/WD-css3-background-20050216/

For the CSS WG,
  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos                               W3C/ERCIM
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France

Received on Tuesday, 2 May 2006 15:08:06 UTC