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Re: Testing THEAD support on user agents (Test file, Linux results)

From: Jon Gunderson <jongund@uiuc.edu>
Date: Fri, 14 Jun 2002 11:11:55 -0500
Message-Id: <>
To: Masayasu Ishikawa <mimasa@w3.org>, w3c-wai-ua@w3.org

We know that scrollable TBODY it is not required by the HTML 4.01 
specification, we are just testing to see if anyone has implemented this 
feature, since it is useful to people with disabilities.
We are doing this test to help in the clarification of the requirements for 
Checkpoint 10.1.  It will probably not be a requirement of UAAG 1.0 since 
there is no implementation experience, but be included in a note stating 
that it is a useful feature to implement.


At 01:01 AM 6/15/2002 +0900, Masayasu Ishikawa wrote:

>Sorry to interrupt, but ...
>"Ian B. Jacobs" <ij@w3.org> wrote:
> > At today's teleconference [1], we talked about support
> > for THEAD in HTML user agents. The context: Do user agents
> > support the rendering where THEAD rows are fixed on the screen
> > while other data cells are scrolled by.
> >
> > To test this, I have published a test table [2] that uses
> > THEAD for the first row (the one starting "Rows").
>I think your expectation is wrong.  "11.2.3 Row groups: the THEAD,
>TFOOT, and TBODY elements" of HTML 4 says as follows [3]:
>     Table rows may be grouped into a table head, table foot, and one
>     or more table body sections, using the THEAD, TFOOT and TBODY
>     elements, respectively. This division enables user agents to
>     support scrolling of table bodies independently of the table head
>     and foot.
>Note that this division *enables* user agents to support scrolling.
>It doesn't mean TBODY must always be scrollable when THEAD is present.
>HTML markup specifies table head - body - foot structure, and that's
>it.  If you want specific presentation, use style sheets.  Your test
>file doesn't attach any style sheets, so it seems quite natural to
>me that user agents don't make tables scrollable.
> > I also tried using 'position:fixed' on the THEAD element
> > for user agents that support CSS fixed positioning. However,
> > since fixed positioning pulls an element out of the flow,
> > the result (at least on Opera) is that the THEAD row is
> > not formatted the same as the other (TBODY) rows. So while
> > the THEAD row remains fixed on the screen, the cells in
> > the other rows don't line up with it, so this approach is
> > not helpful.
>What you want is to make TBODY scrollable, isn't it?  Then don't
>try to do something for THEAD.  Something like
>   TBODY { height: 10em; overflow: auto; }
>would enable user agents to make TBODY scrollable when the height
>of the table body is more than 10em, for example.  It should at least
>work with Gecko-based user agents.
> > [1] http://lists.w3.org/Archives/Public/w3c-wai-ua/2002AprJun/0192
> > [2] http://www.w3.org/WAI/UA/2002/06/thead-test
>[3] http://www.w3.org/TR/html4/struct/tables.html#h-11.2.3
>Masayasu Ishikawa / mimasa@w3.org
>W3C - World Wide Web Consortium

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
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

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WWW: http://www.w3.org/wai/ua
Received on Friday, 14 June 2002 12:10:16 UTC

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