HTML Accessibility Task Force Teleconference

21 Feb 2011


See also: IRC log


Chuck_Pritchard, Rich, Gregory_Rosmaita


<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

<Downchuck> hello

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


Outstanding Bugs


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


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

<richardschwerdtfe> yw

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/


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

<trackbot> Sorry... adding notes to ISSUE-131 failed, please let sysreq know about it

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


Summary of Action Items

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Found Scribe: Gregory_Rosmaita
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Default Present: Gregory_Rosmaita, Rich, +1.949.637.aaaa, Chuck_Pritchard
Present: Chuck_Pritchard Rich Gregory_Rosmaita
Agenda: http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0071.html
Found Date: 21 Feb 2011
Guessing minutes URL: http://www.w3.org/2011/02/21-html-a11y-minutes.html
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