W3C home > Mailing lists > Public > public-html@w3.org > July 2011

Re: hit testing and retained graphics

From: Richard Schwerdtfeger <schwer@us.ibm.com>
Date: Fri, 8 Jul 2011 12:19:38 -0500
To: Charles Pritchard <chuck@jumis.com>
Cc: paniz alipour <alipourpaniz@gmail.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>
Message-ID: <OF5C10ABB2.90B52EA0-ON862578C7.005F1703-862578C7.005F2E25@us.ibm.com>

IE9's ARIA support is improved over IE8.

Rich Schwerdtfeger
CTO Accessibility Software Group



From:	Charles Pritchard <chuck@jumis.com>
To:	paniz alipour <alipourpaniz@gmail.com>
Cc:	Richard Schwerdtfeger/Austin/IBM@IBMUS,
            "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>
Date:	07/08/2011 12:17 PM
Subject:	Re: hit testing and retained graphics
Sent by:	public-canvas-api-request@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>
      wrote:
        IE8 does not support canvas; it shows the fallback content.



        On Jul 7, 2011, at 11:18 PM, paniz alipour <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> 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 element represents embedded content, the user
               can still focus descendants of the canvas element (in the
               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. (Focus has no
               effect on mouse interaction events.) [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>
               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> 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>
                     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-html@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




                     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> 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>
                           To: Richard Schwerdtfeger/Austin/IBM@IBMUS
                           Cc: chuck@jumis.com, franko@microsoft.com,
                           Mike@w3.org, david.bolter@gmail.com,
                           cyns@exchange.microsoft.com,
                           public-canvas-api@w3.org,
                           public-html-a11y@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> 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





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Received on Friday, 8 July 2011 17:20:12 UTC

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