Re: techniques for author-defined UI controls

Response in JRG:


>Introduction/Background
>The first question to be answered is: "What Are Author-defined
>User Interface controls?"
>
>1. Author-defined UI controls include the following:
>   ActiveX controls
>   JavaScript
>   applets
>   ACCESSKEY (HTML4)
>   TABINDEX (HTML4)
>   HTML4 event handlers
>   [your favorite author-defined UI mechanism here!]

JRG: Correct me if I am wrong but in general a user agent does not have 
access to information about keyboard bindings to Active-X or applets since 
these are typically precompiled applications that the user agent is just 
hosting.  In previous discussion in the group these should use the UA 
guidelines in their development to make them accessible.  One special case 
is the user agent itself is using one of these technologies as part of its 
implementation.

HTML4 keyboard event handlers and scripting languages (JavaScript and 
Visual Basic Script) in general is just a reference to a script subroutine 
that is executed when a keyboard event is triggered for a particular 
element.   There is not defined way for a user agent to know what keyboard 
bindings are used in the script response to the event.  The only way a user 
agent could determine this information is through some intelligent analysis 
of the scripts associated with a resource.  With the wide range of 
programming styles associated with script developers and the indirections 
that can be associated with keyboard bindings this would seem to be a 
monumental task and would rarely if ever result in a clear relationship 
between keyboard binding and function.

Jon

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Chair, W3C WAI User Agent Working Group
Division of Rehabilitation - Education Services
College of Applied Life Studies
University of Illinois at Urbana/Champaign
1207 S. Oak Street, Champaign, IL  61820

Voice: (217) 244-5870
Fax: (217) 333-0248

E-mail: jongund@uiuc.edu

WWW: http://www.staff.uiuc.edu/~jongund
WWW: http://www.w3.org/wai/ua

Received on Thursday, 28 October 1999 13:19:02 UTC