- From: Ian Jacobs <ij@w3.org>
- Date: Sat, 08 Jul 2000 13:06:19 -0400
- To: w3c-wai-ua@w3.org
Hello, There are 8 checkpoints in Guideline 3 of the 7 July UA Guidelines [1]. These are the "turn on/off" checkpoints that we started to discuss at the 29 June teleconference [2]. We did not finish our discussion of what "turn on/off" meant, but we resolved that it meant "at least" configuration to not render its subject on loading of content. It may mean more than that for some checkpoints, but at least for the 7 July Guideline, the phrase "turn on/off" has been deleted in favor of more precise wording. Actually, of the 8 checkpoints of Guideline 3, 3.6 and 3.7 concern changing content and have been studied previously. This leaves six checkpoints where we should ask the following questions: 1) Beyond the ability to configure the UA not to render X, do we need to require the ability to configure the UA (globally) to render X at some point after loading? Would that be a P1 requirement? For example, checkpoint 3.3 reads: Allow the user to configure the user agent to render animated or blinking text as motionless text. Do we need to be able to toggle a switch so that text can again be animated and blinking? I don't think that this would be a P1 requirement given that motionless text enables access to text content. 2) Beyond the ability to configure the UA globally to render X, do we need the ability to control the UA so that individual pieces of content can be rendered/not rendered? Here are the checkpoints and some proposals for not adding additional levels of control, except for checkpoint 3.8. 3.1 Allow the user to configure the user agent to not render background images. Proposed: A global configuration to not render background images on loading suffices. If a background image conveys important information, WCAG 1.0 requires a text equivalent. If users cannot read text on the background, they can configure the UA to not render the background image and reload. Note: This does not address the issue of multi-layered presentations and being able to turn off all layers other than the topmost layer. I propose that we not add such a requirement for this version of the Guidelines. 3.2 Allow the user to configure the user agent to not render video. Proposed: A global configuration to not render video on loading suffices since additional control of video is covered by Guideline 4. Thus, users can load all video sources, then control each one independently. 3.3 Allow the user to configure the user agent to render animated or blinking text as motionless text. Proposed: A global configuration to render animated or blinking text as motionless text suffices since lack of motion addresses the accessibility need and since the resulting still text is accessible. 3.4 Allow the user to configure the user agent to render animations or blinking images as motionless images. Proposed: A global configuration to render animated or blinking images as motionless images suffices since lack of motion addresses the accessibility need. 3.5 Allow the user to configure the user agent to not execute scripts and applets. Proposed: A global configuration to not execute scripts and applets suffices since users do not generally have access to the text of a script in order to determine on a script-by-script basis whether to execute it. I agree that some scripts may perform useful tasks at the same time others do not within the same page, but I don't think that users will need that level of control (turn scripts on and off selectively). Users have access to script text under checkpoint 2.1 3.8 Allow the user to configure the user agent to not render images. Proposed: Allow the user to configure the UA to render no images on loading, but thereafter to select individual images for rendering. There is not need for a requirement to allow the user to turn them back off again selectively. Summary: Except for checkpoint 3.8, I propose that the only requirement expressed by these checkpoints be to suppress rendering of content type X on loading. Checkpoint 3.8 should allow users to turn on images selectively if they were not rendered on load. - Ian [1] http://www.w3.org/WAI/UA/WD-UAAG10-20000707/#gl-feature-on-off [2] http://lists.w3.org/Archives/Public/w3c-wai-ua/2000AprJun/0532.html -- Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs Tel: +1 831 457-2842 Cell: +1 917 450-8783
Received on Saturday, 8 July 2000 13:06:21 UTC