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RE: different scope of view in UI design on Canvas

From: Frank Olivier <Frank.Olivier@microsoft.com>
Date: Sat, 24 Sep 2011 18:05:52 +0000
To: Charles Pritchard <chuck@jumis.com>, paniz alipour <alipourpaniz@gmail.com>
CC: Canvas <public-canvas-api@w3.org>, Richard Schwerdtfeger <schwer@us.ibm.com>, Steve Faulkner <faulkner.steve@gmail.com>, "Benjamin Hawkes-Lewis" <bhawkeslewis@googlemail.com>, Cynthia Shelly <cyns@microsoft.com>
Message-ID: <91175A762AB48840AF1473514B26B47544F270EB@TK5EX14MBXC261.redmond.corp.microsoft.com>
IMO, most authors will use canvas to create a single UI control* (positioning it in html/css like any other input control) – this makes the click handling story much easier, as you are not attempting to do click handling for a complex layered windowed UI.

*There could, of course, be several of these controls on the page.

From: Charles Pritchard [mailto:chuck@jumis.com]
Sent: Saturday, September 24, 2011 11:03 AM
To: paniz alipour
Cc: Frank Olivier; Canvas; Richard Schwerdtfeger; Steve Faulkner; Benjamin Hawkes-Lewis; Cynthia Shelly
Subject: Re: different scope of view in UI design on Canvas

http://lists.w3.org/Archives/Public/public-canvas-api/2010JanMar/0147.html


There are three methods for handling clicks: using a bitmap (trading cpu for ram), using an object with bounding box coordinates,
or using the browser's hit testing and layering the elements atop of the canvas.

Paniz, very few authors are using Canvas for elements, at this time.

-Charles

On 9/24/2011 10:57 AM, Frank Olivier wrote:
Not sure I understand your question…
I sent an example to the canvas a11y discussion a while ago – basically, the author has to handle onclick events on the canvas element, and then set the state of the radio/checkbox so that the screen reader can read that. Likewise, when the screen reader changes the radio/checkbox state, the author show redraw the canvas element to indicate the new state.

Thanks
Frank

From: paniz alipour [mailto:alipourpaniz@gmail.com]
Sent: Saturday, September 24, 2011 1:51 AM
To: Charles Pritchard; Canvas; Richard Schwerdtfeger; Steve Faulkner; Frank Olivier; Benjamin Hawkes-Lewis; Cynthia Shelly
Subject: different scope of view in UI design on Canvas

Hello All,

I was thinking about a problem if you had a button a checkbox a radio button in Canvas ,

How would you handle click events of each one of them? I need to know different scope of view and your thought in programming.

please tell me.

Thanks in advance

--
Paniz Alipour

Received on Saturday, 24 September 2011 18:06:22 UTC

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