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Re: hit testing and retained graphics

From: paniz alipour <alipourpaniz@gmail.com>
Date: Fri, 8 Jul 2011 10:48:32 +0430
Message-ID: <CADfq16ikMnphVv-tJrvdPsA-qt0bvXo_b9cHGOe5kZX3-DSXtQ@mail.gmail.com>
To: Richard Schwerdtfeger <schwer@us.ibm.com>
Cc: chuck@jumis.com, cyns@exchange.microsoft.com, david.bolter@gmail.com, franko@microsoft.com, Mike@w3.org, public-canvas-api@w3.org, public-canvas-api-request@w3.org, public-html@w3.org, public-html-a11y@w3.org
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>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
>
> [image: Inactive hide details for paniz alipour ---07/07/2011 09:04:12
> AM---Hi Richard, Yes I get your purpose,except one part :]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>
> To: Richard Schwerdtfeger/Austin/IBM@IBMUS
> Cc: chuck@jumis.com, cyns@exchange.microsoft.com, david.bolter@gmail.com,
> franko@microsoft.com, Mike@w3.org, public-canvas-api@w3.org,
> public-canvas-api-request@w3.org, public-html@w3.org,
> 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
> ------------------------------
>
>
>
> 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*<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
>
>    [image: Inactive hide details for paniz alipour ---07/07/2011 08:42:16
>    AM---Hi Richard, I mean for example I have an interaction UI on]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* <alipourpaniz@gmail.com>>
>    To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>    Cc: *chuck@jumis.com* <chuck@jumis.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-html@w3.org* <public-html@w3.org>, *public-html-a11y@w3.org*<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*<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* <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
>
>       [image: Inactive hide details for paniz alipour ---07/07/2011
>       06:32:18 AM---Hello to all, Maybe you think that this question is not rel]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*<alipourpaniz@gmail.com>
>       >
>       To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>       Cc: *chuck@jumis.com* <chuck@jumis.com>, *franko@microsoft.com*<franko@microsoft.com>,
>       *Mike@w3.org* <Mike@w3.org>, *david.bolter@gmail.com*<david.bolter@gmail.com>,
>       *cyns@exchange.microsoft.com* <cyns@exchange.microsoft.com>, *
>       public-canvas-api@w3.org* <public-canvas-api@w3.org>, *
>       public-html-a11y@w3.org* <public-html-a11y@w3.org>, *
>       public-html@w3.org* <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* <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

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Received on Friday, 8 July 2011 06:19:15 UTC

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