W3C home > Mailing lists > Public > wai-tech-comments@w3.org > March 2001

Focus ambiguity problem

From: Al Gilman <asgilman@iamdigex.net>
Date: Sat, 10 Mar 2001 12:17:25 -0500
Message-Id: <200103101657.LAA5788688@smtp2.mail.iamworld.net>
To: asgilman@iamdigex.net
Cc: Kelly Ford <kelly@kellford.com>
[blind copies of this message are going to several WAI lists:

wai-tech-comments -- for XHTML 2.0 requirements development
w3c-wai-gl -- for HTML accessibility techniques
w3c-wai-ua -- for browser techniques. ]

Kelly Ford has constructed a clearly pathological example that is legal HTML. 

The key stuff is

<HTML>
...
<INPUT type="checkbox" ID="checkKelly"/>
...
<A href="kellysPage.uri"><LABEL for="checkKelly">Kelly Ford</LABEL></A>
...

In the example, the same text is both the content of an anchor element, and
hence the sensitive visible content associated with the "follow the hyperlink"
action and at the same time is the label for a form control with a binary
action, so it could also be the sensitive visible content for the "check the
box that I label" action.

This is a pathological UI feature.  What we have here is a collision of two
contenders to be the onClick action for this sensitive text range.  So we
should be working to eliminate this pathological case as a possibility.

a) for XHTML 2.0 we should put this on a checklist of problems to be fixed.

b) in the HTML techniques for WCAG 2.0 and to the extent we can in the
techniques for WCAG 1.0 (maybe a "see also" reference to the 2.0
techniques) it
should be clear that having any display region overloaded as label for a form
control and content of a hyperlink is to be avoided.

c) User agents will still face the possibility of encountering this
situation. 
One technique in this case would be to handle it with user interface dialogs
similar to how keyboard access to mouse event handlers is implemented, perhaps
by recourse to an auxiliary dialog in which the user is asked to select which
action they wish to take:  follow the link or check the box.

Al 
Received on Saturday, 10 March 2001 11:57:21 GMT

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