- From: Jim Allan <jimallan@tsbvi.edu>
- Date: Mon, 14 Feb 2011 15:43:46 -0600
- To: WAI-ua <w3c-wai-ua@w3.org>
2.9.1 (former 4.9.1) Background Image Toggle: The user can have all background images shown or hidden. (Level A) Intent: It can be difficult for some people to read text or identify images when the background is complex or doesn't contrast well with the foreground. Allowing users to disable the display of background images helps ensure that foreground content remains easy to read. This can also help remove purely decorative distractions, which is important for some users. Users could have the option to have non-transparent backgrounds of a solid color of their choice drawn behind text, rather than turning off background images. Because background images occasionally convey important information, when their display is turned off the user agent should give users access to any alternative content associated with them. This checkpoint does not address issues of multi-layered renderings and does not require the user agent to change background rendering for multi-layer renderings (refer, for example, to the z-index property in Cascading Style Sheets, level 2 ([CSS2], section 9.9.1) Examples: James has a reading disability where he needs text to be clear from distractions that are not related to the text. He configures his user agent not to load background images and navigates to a web page. James then gets only the text from the web page without any images interfering with what he is reading. Related Resources: 1. In CSS, background images may be turned on/off with the background and background-image properties ([CSS2], section 14.2.1). 2. The z-index property in Cascading Style Sheets, level 2 ([CSS2], section 9.9.1) 3. Because background images occasionally convey important information, when their display is turned off the user agent should give users access to any alternative content associated with them. (At the time of this writing, HTML does not support alternative content for background images, but this may be supported in other technologies or future versions.) 4. See Success Criteria 1.4.1 "Configure Text" for more information related to background colors. -- Jim Allan, Accessibility Coordinator & Webmaster Texas School for the Blind and Visually Impaired 1100 W. 45th St., Austin, Texas 78756 voice 512.206.9315 fax: 512.206.9264 http://www.tsbvi.edu/ "We shape our tools and thereafter our tools shape us." McLuhan, 1964
Received on Monday, 14 February 2011 21:44:18 UTC