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- Date: Mon, 13 Sep 2010 09:18:35 +0000
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http://www.w3.org/Bugs/Public/show_bug.cgi?id=10481 --- Comment #50 from steve faulkner <faulkner.steve@gmail.com> 2010-09-13 09:18:34 --- (In reply to comment #49) > The purpose of role="presentation" is to negate an implicit role. > Thus, if it is supposed to make sense that alt=<the empty string> is treateed > as a synonym for role="presentation", then <img> *must* have an implicit role > as well. If <img> can't have an implicit role, then it is meaningless to say > that alt="<the empty string>" negates the <img>s implicit role: > ]] presentation (role) > An element whose implicit native role semantics will not be mapped to the > accessibility API. [[ > [*] http://www.w3.org/WAI.new/PF/aria/complete#presentation > We must hover clarify the effect of role="presentation" on <img>s with a > non-empty @alt: It is seems possible to read ARIA as saying that > role="presentation" should not cause the _alt text_ to become inaccessible for > AT users. It should only cause the <img> to loose its image role. See bug 10614 > against ARIA. > That said: AT doesn't announce "image" for all img elements with role="img". > And as Steven has said [*], they aren't required to do so either: > [*] http://lists.w3.org/Archives/Public/public-html-a11y/2010Sep/0337 > For example, for a link containing nothing but the image [*], then VoiceOver > doesn't announce anything but the link and the @alt text - that the link is an > image, is not announced. > [*] > http://dev.w3.org/html5/spec/embedded-content-1#a-link-or-button-containing-nothing-but-the-image > It is, however, not clear to me whether the question of making known to the > user that the image it is an image, should be completely left over to the AT, > such as in the case with a link with an image. Or if role="presentation" > should/may be used as a tool for making sure that that user isn't disturbed > with such role information. Clearly, HTML5 could possibly open the door for > more "microformats" to be defined where the image-ness is not announced. E.g. > if a <header> elemen contains nothing but an <img>, then it is probably a logo > image, and it shouldn't be necessary to announce that it is an image. > Provided that it is correct that role="presentation" should not make the @alt > text inaccessible to AT users, then some guidelines somewhere, for when it is > acceptable to give an <img> role="presentation" would be useful. Of course, > alt="<the-emtpy-string>" is obvious. But also, images which only contain > characters - e.g. when the image is a text and the @alt just contains that text > - seem like a candiate for when role="presentation" is a SHOULD. Such a thing > seems consistent with ARIA, which says: > ]] The intended use is when an element is used to change the look of the page > but does not have all the functional, interactive, or structural relevance > implied by the element type [[ > [*] http://www.w3.org/WAI.new/PF/aria/complete#presentation i asked a question about use of role="presentaion" on <img> on the wai-xtech list last month: http://lists.w3.org/Archives/Public/wai-xtech/2010Aug/0014.html -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug.
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