Yes. Flash has retained mode graphics. We have it now in canvas in that we can create a DOM node but we just can't associate it with the object being drawn. Canvas has one big drawing object and associated context - the canvas itself. Without the ability to tell a magnifier where the objects are on the canvas, represented in the fallback content, we cannot direct the magnifier to zoom on the object when it receives focus or when the AT simply wants to zoom to the object in the accessibility object tree produced by the user agent from the canvas subtree. In an earlier proposal I suggested producing a subclass of the canvas object that had the same context APIs to represent drawing objects to start. ... that is if we were to produce canvas with full retained mode graphics. Frankly, this is not unlike what developers are forced to do. Developers are producing separate canvas elements and overlaying them on top of canvas to produce drawing objects that appear on top of canvas. Rich Schwerdtfeger CTO Accessibility Software Group From: Maciej Stachowiak <mjs@apple.com> To: Silvia Pfeiffer <silviapfeiffer1@gmail.com> Cc: Richard Schwerdtfeger/Austin/IBM@IBMUS, Charles McCathieNevile <chaals@opera.com>, Cameron McCormack <cam@mcc.id.au>, Charles Pritchard <chuck@jumis.com>, Cynthia Shelly <cyns@microsoft.com>, david.bolter@gmail.com, Frank Olivier <Frank.Olivier@microsoft.com>, "Tab Atkins Jr." <jackalmage@gmail.com>, Mike@w3.org, public-canvas-api@w3.org, public-html@w3.org, public-html-a11y@w3.org, public-html-a11y-request@w3.org Date: 06/28/2011 12:26 PM Subject: Re: hit testing and retained graphics Sent by: public-canvas-api-request@w3.org On Jun 28, 2011, at 7:35 AM, Silvia Pfeiffer wrote: On Mon, Jun 27, 2011 at 10:41 PM, Richard Schwerdtfeger <schwer@us.ibm.com> wrote: What about Adobe Flash in this area? Adobe Flash is used for many of the same use cases that canvas is used for. Is Flash more accessible? How do they do it? Is Flash prohibited because it's not accessible? I'm not an expert on Adobe Flash accessibility, but my understanding is that its drawing model is more like SVG (retained mode) than like Canvas (immediate mode). Thus, there are persistent objects that represent your drawing. Regards, Maciej
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