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Re: hit testing and retained graphics

From: Charles Pritchard <chuck@jumis.com>
Date: Fri, 08 Jul 2011 10:16:17 -0700
Message-ID: <4E173B61.3020000@jumis.com>
To: paniz alipour <alipourpaniz@gmail.com>
CC: Richard Schwerdtfeger <schwer@us.ibm.com>, "cyns@exchange.microsoft.com" <cyns@exchange.microsoft.com>, "david.bolter@gmail.com" <david.bolter@gmail.com>, "franko@microsoft.com" <franko@microsoft.com>, "Mike@w3.org" <Mike@w3.org>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>, "public-canvas-api-request@w3.org" <public-canvas-api-request@w3.org>, "public-html@w3.org" <public-html@w3.org>, "public-html-a11y@w3.org" <public-html-a11y@w3.org>
You are correct: IE9 introduced support for Canvas and the sub-tree 
(with drawFocusRing).

IE8 introduced support for WAI-ARIA.

You may view a page as it would render in IE7 and IE8 by using IE9s F12 
Developer Tools
and changing the compatibility view mode.



On 7/7/2011 11:41 PM, paniz alipour wrote:
> I knew Charles,but I remember that shadow Dom and fallback content 
> sub-tree is just supported in IE9.Am I right?
>
> On Fri, Jul 8, 2011 at 10:51 AM, Charles Pritchard <chuck@jumis.com 
> <mailto:chuck@jumis.com>> wrote:
>
>     IE8 does not support canvas; it shows the fallback content.
>
>
>
>     On Jul 7, 2011, at 11:18 PM, paniz alipour <alipourpaniz@gmail.com
>     <mailto:alipourpaniz@gmail.com>> wrote:
>
>>     Hi Richard,
>>
>>     There was some thing marvelous! As I found out shadow Dom or
>>     fallback content was just supported in IE9 ,but I saw that it is
>>     run in IE8 too.
>>
>>     I mean your sample that you had sent it for me.
>>
>>     Am I right ? What has happened?
>>
>>     Thanks
>>
>>     On Thu, Jul 7, 2011 at 6:45 PM, Richard Schwerdtfeger
>>     <schwer@us.ibm.com <mailto:schwer@us.ibm.com>> wrote:
>>
>>         Yes, the author draws the widget on the canvas based on the
>>         information in the canvas subtree.
>>
>>         If you don't use the subtree it won't be in the keyboard
>>         navigation order and you can't provide the accessibility
>>         information
>>
>>         From the HTML 5 spec on canvas:
>>         http://dev.w3.org/html5/spec/the-canvas-element.html#the-canvas-element
>>
>>         "When a _canvas_
>>         <http://dev.w3.org/html5/spec/the-canvas-element.html#the-canvas-element>element
>>         _represents_
>>         <http://dev.w3.org/html5/spec/rendering.html#represents>_embedded
>>         content_
>>         <http://dev.w3.org/html5/spec/content-models.html#embedded-content>,
>>         the user can still focus descendants of the _canvas_
>>         <http://dev.w3.org/html5/spec/the-canvas-element.html#the-canvas-element>element
>>         (in the _fallback content_
>>         <http://dev.w3.org/html5/spec/content-models.html#fallback-content>).
>>         When an element is focused, it is the target of keyboard
>>         interaction events (even though the element itself is not
>>         visible). This allows authors to make an interactive canvas
>>         keyboard-accessible: authors should have a one-to-one mapping
>>         of interactive regions to focusable elements in the _fallback
>>         content_
>>         <http://dev.w3.org/html5/spec/content-models.html#fallback-content>.
>>         (Focus has no effect on mouse interaction events.)
>>         _[DOMEVENTS]_
>>         <http://dev.w3.org/html5/spec/the-canvas-element.html#DOMEVENTS>"
>>
>>         Attached is a basic example:
>>
>>
>>         /(See attached file: CanvasEditor.html)/
>>
>>
>>         Rich Schwerdtfeger
>>         CTO Accessibility Software Group
>>
>>         <graycol.gif>paniz alipour ---07/07/2011 09:04:12 AM---Hi
>>         Richard, Yes I get your purpose,except one part :
>>
>>
>>         From: paniz alipour <alipourpaniz@gmail.com
>>         <mailto:alipourpaniz@gmail.com>>
>>         To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>>         Cc: chuck@jumis.com <mailto:chuck@jumis.com>,
>>         cyns@exchange.microsoft.com
>>         <mailto:cyns@exchange.microsoft.com>, david.bolter@gmail.com
>>         <mailto:david.bolter@gmail.com>, franko@microsoft.com
>>         <mailto:franko@microsoft.com>, Mike@w3.org
>>         <mailto:Mike@w3.org>, public-canvas-api@w3.org
>>         <mailto:public-canvas-api@w3.org>,
>>         public-canvas-api-request@w3.org
>>         <mailto:public-canvas-api-request@w3.org>, public-html@w3.org
>>         <mailto:public-html@w3.org>, public-html-a11y@w3.org
>>         <mailto:public-html-a11y@w3.org>
>>         Date: 07/07/2011 09:04 AM
>>
>>         Subject: Re: hit testing and retained graphics
>>         Sent by: public-canvas-api-request@w3.org
>>         <mailto:public-canvas-api-request@w3.org>
>>         ------------------------------------------------------------------------
>>
>>
>>
>>         Hi Richard,
>>
>>         Yes I get your purpose,except one part :
>>
>>         _ You control the drawing _ ?!
>>
>>
>>         in this sentence:
>>         If you wanted to create a canvas rendering of a checkbox in
>>         the fallback content, on the canvas that was 70X70 you can do
>>         it. You control the drawing
>>
>>         and some thing else if a developer doesn't use sub-tree in
>>         shadow DOM? what does happen?
>>
>>
>>         Thanks
>>
>>
>>         On Thu, Jul 7, 2011 at 6:25 PM, Richard Schwerdtfeger
>>         <_schwer@us.ibm.com_ <mailto:schwer@us.ibm.com>> wrote:
>>
>>               Hi Paniz,
>>
>>               I am not sure if I am answering your question but you
>>               could create these objects on canvas and create
>>               equivalents in the canvas subtree whereby the canvas is
>>               a rendering of the HTML element in the canvas subtree
>>               and you can give it any size and dimension you want.
>>               All the elements in canvas subtree could be placed in
>>               the keyboard navigation order. If you wanted to create
>>               a canvas rendering of a checkbox in the fallback
>>               content, on the canvas that was 70X70 you can do it.
>>               You control the drawing. Accessibility wise I don't yet
>>               have a way to communicate those bounds to the
>>               accessibility API. This is what we have been
>>               discussing. We have been discussing creating a drawing
>>               path on canvas that represents the bounds of the
>>               object, binding it to the canvas subtree element (which
>>               is in the keyboard navigation order). In doing so we
>>               would have the user agent to do hit testing on the
>>               drawing objects in canvas and pass the pointing event
>>               to the corresponding object in the accessibility
>>               subtree. The bounds of the object used for hit testing
>>               would be passed to the corresponding accessible object
>>               (corresponding the to the DOM element in the subtree).
>>               Now a magnifier would know how to zoom to the
>>               corresponding 70x70 checkbox on the canvas.
>>
>>               To be honest, this is not new. This is how desktops
>>               like Windows work. You have a graphic on the screen
>>               bound to a COM object which supports MSAA. The MSAA
>>               bounding rectangle is retrieved from the retained mode
>>               graphic.
>>               We are arguing for putting this capability into canvas.
>>
>>               Rich
>>
>>
>>               Rich Schwerdtfeger
>>               CTO Accessibility Software Group
>>
>>               <graycol.gif>paniz alipour ---07/07/2011 08:42:16
>>               AM---Hi Richard, I mean for example I have an
>>               interaction UI on canvas as like web pages,
>>
>>
>>
>>               From: paniz alipour <_alipourpaniz@gmail.com_
>>               <mailto:alipourpaniz@gmail.com>>
>>               To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>>               Cc: _chuck@jumis.com_ <mailto:chuck@jumis.com>,
>>               _cyns@exchange.microsoft.com_
>>               <mailto:cyns@exchange.microsoft.com>,
>>               _david.bolter@gmail.com_
>>               <mailto:david.bolter@gmail.com>, _franko@microsoft.com_
>>               <mailto:franko@microsoft.com>, _Mike@w3.org_
>>               <mailto:Mike@w3.org>, _public-canvas-api@w3.org_
>>               <mailto:public-canvas-api@w3.org>, _public-html@w3.org_
>>               <mailto:public-html@w3.org>, _public-html-a11y@w3.org_
>>               <mailto:public-html-a11y@w3.org>
>>               Date: 07/07/2011 08:42 AM
>>
>>               Subject: Re: hit testing and retained graphics
>>               Sent by: _public-canvas-api-request@w3.org_
>>               <mailto:public-canvas-api-request@w3.org>
>>               ------------------------------------------------------------------------
>>
>>
>>
>>
>>               Hi Richard,
>>
>>               I mean for example I have an interaction UI on canvas
>>               as like web pages,
>>
>>               textbox,radiobutton ,checkbox,.... .I want to know
>>               these elements that are drawn or are images on canvas
>>
>>               could be incredible,Of course they can but in your
>>               opinion how many percent it is possible(forexample
>>               checkbox with height 70 and width 70)
>>
>>               Best Regards
>>
>>               On Thu, Jul 7, 2011 at 6:02 PM, Richard Schwerdtfeger
>>               <_schwer@us.ibm.com_ <mailto:schwer@us.ibm.com>> wrote:
>>                     Hi Paniz,
>>
>>                     I am not quite following you. Could you please
>>                     provide more detail?
>>
>>                     Thanks,
>>
>>                     Rich
>>
>>
>>                     Rich Schwerdtfeger
>>                     CTO Accessibility Software Group
>>
>>                     <graycol.gif>paniz alipour ---07/07/2011 06:32:18
>>                     AM---Hello to all, Maybe you think that this
>>                     question is not related to this discussion,
>>
>>
>>                     From: paniz alipour <_alipourpaniz@gmail.com_
>>                     <mailto:alipourpaniz@gmail.com>>
>>                     To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>>                     Cc: _chuck@jumis.com_ <mailto:chuck@jumis.com>,
>>                     _franko@microsoft.com_
>>                     <mailto:franko@microsoft.com>, _Mike@w3.org_
>>                     <mailto:Mike@w3.org>, _david.bolter@gmail.com_
>>                     <mailto:david.bolter@gmail.com>,
>>                     _cyns@exchange.microsoft.com_
>>                     <mailto:cyns@exchange.microsoft.com>,
>>                     _public-canvas-api@w3.org_
>>                     <mailto:public-canvas-api@w3.org>,
>>                     _public-html-a11y@w3.org_
>>                     <mailto:public-html-a11y@w3.org>,
>>                     _public-html@w3.org_ <mailto:public-html@w3.org>
>>                     Date: 07/07/2011 06:32 AM
>>
>>                     Subject: Re: hit testing and retained graphics
>>                     ------------------------------------------------------------------------
>>
>>
>>
>>
>>                     Hello to all,
>>
>>                     Maybe you think that this question is not related
>>                     to this discussion,
>>
>>                     But I want to know whether the web widget that
>>                     are located on canvas,
>>
>>                     are they incredible .I mean a check box with
>>                     height 70,weight 70,
>>
>>                     or no it will design as the common web widget on
>>                     websites?
>>
>>                     Thanks
>>
>>                     On Fri, Jun 17, 2011 at 11:11 PM, Richard
>>                     Schwerdtfeger <_schwer@us.ibm.com_
>>                     <mailto:schwer@us.ibm.com>> wrote:
>>                           Charles, Frank, Mike,
>>
>>                           I am back from vacation. How far do we need
>>                           to go with hit testing? Right now I am
>>                           looking at associating a closed draw path
>>                           with a DOM object in the canvas subtree. We
>>                           would then need to address the routing of
>>                           pointing device input events to the DOM
>>                           object. The drawing path can be used to
>>                           provide bound information to platform
>>                           accessibility API.
>>
>>                           Do we need to bind any other drawing
>>                           properties to the canvas object - similar
>>                           to the way device context's are handled on
>>                           graphic subsystems like Windows?
>>
>>                           Mike, I am including you as before I went
>>                           on vacation you indicated that a number of
>>                           developers desired this feature and wanted
>>                           to be involved.
>>
>>                           Rich
>>
>>
>>                           Rich Schwerdtfeger
>>                           CTO Accessibility Software Group 
>>
>>
>>
>>                     -- 
>>                     Paniz Alipour
>>
>>
>>
>>
>>
>>               -- 
>>               Paniz Alipour
>>
>>
>>
>>
>>
>>         -- 
>>         Paniz Alipour
>>
>>
>>
>>
>>     -- 
>>     Paniz Alipour
>
>
>
>
> -- 
> Paniz Alipour
Received on Friday, 8 July 2011 17:16:55 UTC

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