minutes: Canvas Subteam weekly telecon 2011-02-21 [draft]

aloha!

minutes from the Canvas Subteam of the HTML Accessibility Task Force's 
21 February 2011 weekly meeting can be accessed as hypertext from:

http://www.w3.org/2011/02/21-html-a11y-minutes.html

as an IRC log from:

http://www.w3.org/2011/02/21-html-a11y-irc

and as plain text following this announcement -- as usual, please log
any errors, omissions, clarifications and the like by replyiing-to 
this announcement on-list...

note that the following RESOLUTION was agreed to at today's Canvas
meeting:

   RESOLUTION: Submit 
   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection 
   Change Proposal to HTML WG as it has been available for review 
   and individuals have been asked to review it specifically

     _________________________________________________________

                               - DRAFT -

             HTML Accessibility Task Force Teleconference

21 Feb 2011

Agenda
http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0071.html

   See also: IRC log - http://www.w3.org/2011/02/21-html-a11y-irc

Attendees

   Present
          Chuck_Pritchard, Rich, Gregory_Rosmaita

   Regrets
   Chair
          Rich

   Scribe
          Gregory_Rosmaita

Contents

     * Topics
         1. Getting Started/Updates
         2. Outstanding Bugs
         3. Strategy for positioning fallback content relative to
            corresponding canvas UI drawing counterparts.
     * Summary of Action Items
     _________________________________________________________

   <trackbot> Date: 21 February 2011

   <richardschwerdtfe> Meeting: HTML Canvas Accessibility Subteam

   <scribe> scribe: Gregory_Rosmaita

   <scribe> scribenick: oedipus

   Google Web Toolkit (GWT) 2.2 released this week now includes support
   for the HTML5 Canvas tag, which enables building "dynamic
   images/animations/transitions all in HTML with GWT."

   <richardschwerdtfe> Agenda is here:

   <richardschwerdtfe>
   http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0071.html


Getting Started/Updates

   RS: if FrankO doesn't join, will submit proposal as last circulated
   to the list

   <Downchuck> http://mugtug.com/darkroom/

   RS: chuck, do you have an example?

   CP: still bug-fixing

   canvas 2d API change proposal cover letter:
   http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0070.html

   canvas 2d API change proposal:
   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection

   CanvasEditor.html:
  
http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/att-0071/CanvasEditor.html

   HTML_Canvas_2DContext20110217.html:
  
http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/att-0071/HTML_Canvas_2DContext20110217.html

   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection


Outstanding Bugs

   http://www.w3.org/Bugs/Public/show_bug.cgi?id=11328

   RS: pixel resolutoin -- what happened with that?

   CP: hixie and mozilla against that kind of work -- is a problem --
   MS already exposes it
   ... hixie handed over to CSS WG where it sits

   RS: what to do?

   CP: "slip in" via CSS
   ... for FF can do collectoin of media queries
   ... problem because vetoed by mozilla -- do have a workaround, but
   don't know what to do other than to bring to webkit'

   RS: close this bug?

   CP: assigned to CSS OM
   ... CSS resopnse "backlog is huge" -- sitting for at least a month

   resize event during zoom:
   http://www.w3.org/Bugs/Public/show_bug.cgi?id=11329

   CP: everyone in agreement -- needs to be added to specs

   <richardschwerdtfe>
   http://www.w3.org/Bugs/Public/show_bug.cgi?id=11329

   <Downchuck> #canvas.CompatibilityMozScreen { width: 1px; } @media
   all and (min--moz-device-pixel-ratio: .3) {
   #canvas.CompatibilityMozScreen { width: .3px; } }

   <Downchuck> that's the trick for Firefox zoom

   CP: asignee in bug tracker, don't need to do ourselves

   http://www.w3.org/Bugs/Public/show_bug.cgi?id=11342

   RS: addressed in latest drafts and change proposal
   ... in change proposal under "Positive Effects"
   ... text metrics in Canvas 2D API
  
http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/att-0071/HTML_Canvas_2DContext20110217.html

   CP: setCaretSelection API -- if selection not in focus, still works

   RS: changed that to accomodate that


Strategy for positioning fallback content relative to corresponding
canvas UI drawing counterparts.

   RS: will take a lot longer than we have -- create issue for LC next
   step -- either accept or not
   ... strategies for positioning content
   ... first, imagemap provides coordinate info -- can do that or use
   javascript according to FrankO

   CP: imagemap proposal been struck down

   RS: not doing imagemap, but interesting that elements with imagemap
   can take coordinates, so can fallback content for CANVAS provide
   coordinates through fallback

   CP: might be able to track positions via jscript object or can stick
   directly into DOM -- doesn't harm anything
   ... may have an effect --- no one uses fallback content to toggle on
   and off -- not available, but supposed to be a long-term option

   RS: reasonable strategy for doing this? get width and height, right?

   CP: yes, full CSS spectrum of adding info to elements
   ... keeping eye out for use case for exposing all of that data --

   \CP: not addressed yet in CSS Transformations

   CP: CSS Transformations don't provide AT with updates that screen
   has moved; if canvas animated, as soon as move over few pixels, have
   to update a lot of elements -- complexity we need to keep in mind

   RS: imagemap -- coordinates relative to context they are in?

   CP: yes

   RS: if UA moved, UA would update coordinates; app author only has to
   worry to extent that are visible on screen
   ... can't scroll and imagemap

   CP: could get same using SVG to define all shapes and z-index in
   relation to each other
   ... allowed to use transparent SVG elements to do these things (get
   a whole lot of data to AT) -- use DrawFocusRing and CaretSelection
   and telling it only what caret is on

   RS: could use x,y coordinate to move magnifier to whereever one
   wants -- not tied to caret in A11y API -- could position wherever
   one wants -- zoom to drawning object, put caret there
   ... second issue: what other ways can we set positioning other than
   x,y coordinates -- javascript?

   CP: not sure what FrankO means just by "javascript"

   RS: can do via CSS

   CP: may be referring to CSS absolute positioning
   ... in demo i have on darkroom site, am able to use our semantics
   (DrawFocusRing and CaretSelection) -- have TTS via google translate
   API running -- alternating via Mac and PC so can recreate each step
   on each platform -- works as well in my browser as in their apps --
   when scroll, some events don't get set up the way they should so
   accessibiolity focus ring gets stuck until type something in

   RS: if scroll window, position moves -- drawFocusRing around object
   is necessary step for retaining focus when scrolled

   CP: doesn't actually update where FocusRingSelection is on element
   -- does update in some cases, but only if change between 2 elements
   ... if send focus event on same element, will ignore repeated calls
   to update x,y position
   ... using our semantics, trying to get same result as apple

   note: CP referring to http://mugtug.com/darkroom/

   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection

   RS: add something to references in Chanqe Proposal so that
   http://mugtug.com/darkroom/ cited
   ... what to call this? canvas focus tracking simulation?

   CP: good -- focus management too

   RS: put under "development"

   CP: fine with me

   RS: now under "references" in change proposal

   CP: JAWS doesn't work as well in IE9

   GJR: RC beta of IE9 very sporadic with speech--problem updating info
   when switch tab to tab; forms controls often don't respond to
   keyboard input, but need routing of JAWS cursor to PC cursor, etc.
   -- very unstable

   CP: shift-based part necessary at moment -- every UA has different
   method to get focus
   ... working through a lot of quirks to get same result on the
   software combos we discussed

   GJR: am running FF so can use Chatzilla so can't check using IE9
   right now -- will do when CP alerts us that bug-fixing de-quirking
   done for testing

   <Downchuck> I'm using "shift+space" to turn a11y on the app at the
   moment

   <Downchuck> yes, will dequirk

   <richardschwerdtfe>
   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection#References

   RS: propose we adjourn

   CP: ok

   GJR: ok

   ISSUE-131: Should we add a caret location API to canvas, or is the
   focus API sufficient?
   http://www.w3.org/html/wg/tracker/issues/131

   GJR: we have done our due dilligence in notifiying others

   RS: barring no objections at this time from Microsoft or Mozilla
   does Canvas Subgroup agree to submit change proposal for HTML WG
   ISSUE-131?

   CP: no objection

   GJR: no objection

   proposed RESOLUTION: Submit
   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection
   Change Proposal to HTML WG as has been available for review

   RESOLUTION: Submit
   http://www.w3.org/html/wg/wiki/ChangeProposals/CaretSelection
   Change Proposal to HTML WG as it has been available for review and
   individuals have been asked to review it specifically

   RS: will send email to Sam Ruby, Paul Cotton and Maciej to alert
   that change proposal for HTML WG Issue 131 complete and vetted by
   subteam

   [adjournded]

Summary of Action Items

   [End of minutes]
     _________________________________________________________

Received on Monday, 21 February 2011 21:06:50 UTC