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Re: Javascript Image Roll-over

From: Charles McCathieNevile <charles@sidar.org>
Date: Thu, 16 Jan 2003 09:57:44 +1100
Cc: WAI-IG <w3c-wai-ig@w3.org>
To: Joe Clark <joeclark@joeclark.org>
Message-Id: <C2492C4A-28DC-11D7-877C-000A95678F24@sidar.org>


On Thursday, Jan 16, 2003, at 07:08 Australia/Melbourne, Joe Clark 
wrote:

> Eric Meyer and I had written, in research for my book:
>
>>>>     So what it comes down to is a question of which states should 
>>>> take precedence over others.  Is focus more "necessary" than hover, 
>>>> or active?  That's really what I was asking you, as an 
>>>> accessibility guru, to answer.
>>>
>>> I would say yes. You need to be able to tell where the focus is. 
>>> That may necessitate making the focus state big-arse ugly so it can 
>>> be spotted easily.
>>
>>    Right, but what if the focus style (for the sake of argument) is 
>> just a color change.  I know it should be more, but let's say it's 
>> just that.  Is it okay to put that style in the middle of the stack, 
>> and have the hover and active styles override it during those events? 
>> For example:
>> [snip]

>> The same basic hierarchy of effects applies.  Is it acceptable to 
>> have the hover and active styles temporarily override the focus 
>> style, or are there accessibility reasons to always have the focus 
>> style visible no matter what else is happening?  I guess that's my 
>> real question.
>
> I have not quite figured this out myself. Further, you can add 
> :visited to the mix. I actually have the following in some of my 
> stylesheets:

I think the answer is that it is better to use effects that don't 
conflict. For example I have a use style sheet for editing that 
identifies targets with properties like overlines, so I know if a link 
is also marked as a target or not (I identify those with the more 
traditional underline).

In this case, where people have two effective focuses (the mouseover, 
which says where a click will be activated, and the focus, which says 
where a return will be activated) it is probably better to keep them 
distinct. There is a bit of an implementation mess here, because some 
systems send a click event from the keyboard and others don't. <sigh/>

cheers

Chaals

--
Charles McCathieNevile           charles@sidar.org
Fundación SIDAR                       http://www.sidar.org
Received on Wednesday, 15 January 2003 17:58:20 GMT

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