[css3-images] Image fallback feature's dependency on media fragments

• From: Kang-Hao (Kenny) Lu <kennyluck@csail.mit.edu>
• Date: Thu, 09 Feb 2012 01:15:36 +0800
• To: WWW Style <www-style@w3.org>
• Message-ID: <4F32ADB8.4010501@csail.mit.edu>

3.2. Image Fallbacks and Annotations: the ‘image()’ notation

  # So that authors can take advantage of CSS's forwards-compatible parsing
  # rules to provide a fallback for image slices, implementations that
  # support the ‘image()’ notation must support the xywh=#,#,#,# form of
  # media fragment identifiers for images. [MEDIA-FRAGS]

Is this what implementers are planning to do? It it is, there's nothing
I would complain. If it is not, as the feature of media fragments seems
to be heavier than than feature of image fallback, it seems enough here
if we only require "implementations that support the 'image()' notation
but not xywh=#,#,#,# must treat such URL as a 404 image" so Example 4:

  # background-image: url('swirl.png'); /* old UAs */
  # background-image: image('sprites.png#xywh=10,30,60,20'); /* new UAs */

can be written as

  | background-image: url('swirl.png'); /* old UAs */
  | background-image: image('sprites.png#xywh=10,30,60,20', 'swirl.png');
  | /* new UAs that support fallback image. Might or might not support
media fragment */

What are implementers' plans here?


Cheers,
Kenny
 

Received on Wednesday, 8 February 2012 17:18:26 UTC