- From: Ian Jacobs <ij@w3.org>
- Date: Thu, 15 Jul 1999 11:46:44 -0400
- To: w3c-wai-ua@w3.org
- CC: ij@w3.org
Hello, I received an action item at the 14 July teleconf [1] to propose text for Guideline 1 about the relationship between device independent and system conventions. The issue originally raised by Harvey [2] concerned using the mouse to input text. Do user agents that don't provide an on-screen keyboard fail to satisfy checkpoint 1.1 (in [3])? To summarize the discussion of [1]: - User agents should not all be required to implement on-screen keyboards. - The operating system should provide an on-screen keyboard that may be used by any software running on the system. Apparently lots of software exists anyway to do this. - User agents should take input (mouse and keyboard events) through standard system interfaces. One proposal is to modify the wording of checkpoint 1.1 from: Ensure that all functionalities offered by the user agent interface are available through all supported input devices. to somethinge like: Ensure that all functionalities offered by the user agent interface are available through standard interfaces for input devices supported by the operating system. Discussion at the meeting suggested that there were only two interfaces actually used: for pointing device and keyboard, and that other devices ended up using those two. (This is suggested at the MS developer site by [4], the definition of "Event", which includes only keyboard and mouse events). Jim Allan suggested that the term "device-independence" continue to be used in various checkpoints and that we explain what this is supposed to mean in the rationale of Guideline 1. Here's a first draft for a new rationale section for Guideline 1: Since not all users make use of the same hardware for input or output, software must be designed to work with the widest possible range of devices. For instance, not all users have pointing devices, so software must not rely on them for operation. Users must be able to reach all functionalities offered by the user agent interface with all input devices supported by the underlying system. The best way to make this possible is to design software that follows system conventions and uses standard APIs for user input and output. When user agents use these standard interfaces, assistive technologies and other software can programmatically trigger mouse or keyboard events. For instance, some users who may not be able to enter text easily through a standard keyboard can still use special devices or an on-screen keyboard to operate the user agent. Standard interfaces make it possible for users to use a variety of input and output devices (and to develop new ones), including pointing devices, keyboards, braille devices, head wands, microphones, touch screens, speech synthesizers, and more. Using standard interfaces also allows international users with very different keyboards to use software. [@@this sounds good. is it true? -editor] Please refer also to Guideline 12, which discusses the importance to accessibility of following operating system conventions. We could also add a definition of "device independence" to the glossary: Device Independence: The ability to make use of software via any input or output device supported by the operating system. User agents should follow system conventions and use standard APIs for device input and output. Comments welcome, - Ian [1] http://lists.w3.org/Archives/Public/w3c-wai-ua/1999JulSep/0018.html [2] http://lists.w3.org/Archives/Public/w3c-wai-ua/1999AprJun/0204.html [3] http://www.w3.org/WAI/UA/WAI-USERAGENT-19990709/ [4] http://msdn.microsoft.com/library/officedev/off2000/defEvent.htm -- Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs Tel/Fax: +1 212 684-1814
Received on Thursday, 15 July 1999 11:44:18 UTC