- From: Steve Faulkner <faulkner.steve@gmail.com>
- Date: Fri, 27 Apr 2012 09:21:48 +0100
- To: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
- Cc: PFWG Public Comments <public-pfwg-comments@w3.org>, W3C WAI-XTECH <wai-xtech@w3.org>
- Message-ID: <CA+ri+VmUQ2jpsAZXx-jrDAo_5qrGYN4+m1LxTT2W=c+tHQ5=ug@mail.gmail.com>
Hi Ben, Have not been following this discussion closely, but just wanted to provide info about an implementation detail. In all supporting browsers CSS display:none is applied to elements with the hidden attribute. regards stevef On 27 April 2012 07:44, Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>wrote: > Comment on Accessible Rich Internet Applications (WAI-ARIA) 1.0 > > Comment based on Editor's Draft of 16 April 2012, archived at: > > http://www.webcitation.org/673DWtJcY > > §6.6 defines a conformance requirement for the "aria-hidden" property: > > "Authors MUST set aria-hidden="true" on content that is not displayed, > regardless of the mechanism used to hide it." > > This is problematic, because some host languages authors have neither > complete control nor certain knowledge of whether content is > displayed. For example, an author might specify the HTML5 @hidden > attribute, and the user might expose hidden elements using a user > stylesheet. Since user agents know whether or not they are displaying > content, why is this an author requirement rather than a user agent > requirement? > > The spec need to define "displayed". Does it mean the same thing as > HTML5's "being rendered"? > > http://dev.w3.org/html5/spec/rendering.html#being-rendered > > If so, then this conformance requirement is counter-productive, since > it would require authors to set "aria-hidden" on <canvas> sub-DOM, > eliminating the content from appearing as objects in the accessibility > tree. > > The spec also says aria-hidden "Indicates that the element and all of > its descendants are not visible or perceivable to any user as > implemented by the author." Is an element "visible or perceivable" if > it's acting as a backing store for <canvas>? What does the > qualification "as implemented by the author" mean? > > One reason to use CSS mechanisms rather than semantic mechanisms like > "hidden" is in order to show content to users who do not apply user > agent styles. Is "as implemented by the author" meant to imply the > application of author style suggestions, in which case aria-hidden > must be applied? Or is it more important that the author is > intentionally not hiding it from all users, in which case aria-hidden > must not be applied? > > What if the author provides multiple stylesheets, and elements are > hidden in one stylesheet but visible in another stylesheet? > > The spec includes a note that "Note: Authors are reminded that > visibility:hidden and display:none apply to all CSS media types" > > This is erroneous. While "display" applies to all media types, > "visibility" only applies to "visual" media types, as stated clearly > in the CSS specification's definition of the property to which ARIA > directly links: > > http://www.w3.org/TR/CSS21/visufx.html#visibility > > -- > Benjamin Hawkes-Lewis > > -- with regards Steve Faulkner Technical Director - TPG www.paciellogroup.com | www.HTML5accessibility.com | www.twitter.com/stevefaulkner HTML5: Techniques for providing useful text alternatives - dev.w3.org/html5/alt-techniques/ Web Accessibility Toolbar - www.paciellogroup.com/resources/wat-ie-about.html
Received on Friday, 27 April 2012 08:22:39 UTC