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Re: change proposal: Provide accessibility implementation information (in the Canvas 2d Context specification) for focus rectangle and caret

From: Maciej Stachowiak <mjs@apple.com>
Date: Mon, 08 Mar 2010 13:01:35 -0800
Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, public-canvas-api@w3.org, HTMLWG WG <public-html@w3.org>, Richard Schwerdtfeger <schwer@us.ibm.com>
Message-id: <0B258772-C235-495B-9FDD-FFA293F34B75@apple.com>
To: Steven Faulkner <faulkner.steve@gmail.com>

On Mar 4, 2010, at 4:41 AM, Steven Faulkner wrote:

> change proposal based on changes (written by Rich S) to the canvas 2d
> context spec
> http://www.w3.org/html/wg/wiki/ChangeProposals/canvasaccessibility
>
> resolves bug 8722 (http://www.w3.org/Bugs/Public/show_bug.cgi?id=8722)
>

<chair hat off>

It seems odd to me that this proposal overloads drawFocusRing to also  
handle tracking the caret in a canvas:

1) The caret is a kind of selection, not a kind of focus ring. Rather  
than overloading drawFocusRing, there should be a way to indicate a  
selection region, possibly collapsed to a caret.

2) On many operating systems the caret blinks in the default system  
appearance, so using a single call to draw it once will not do. At  
best you can report its position and it has to be up to the specific  
Web application to manage drawing it.

3) It seems to me that if the <canvas> has a navigable/accessible  
subdom, then it can semantically indicate focus and selection by  
placing the DOM selection somewhere in the subdom. The only piece  
missing is associating that with some screen coordinates.

Regards,
Maciej
Received on Monday, 8 March 2010 21:02:10 GMT

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