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User Agent Working Group Minutes, 10 Feb 2011

From: Simon Harper <simon.harper@manchester.ac.uk>
Date: Thu, 10 Feb 2011 19:37:10 +0000
Message-ID: <4D543E66.3060001@manchester.ac.uk>
To: UAWG list <w3c-wai-ua@w3.org>
- DRAFT -
User Agent Accessibility Guidelines Working Group Teleconference
10 Feb 2011

IRC log http://www.w3.org/2011/02/10-ua-irc
HTML Minutes: http://www.w3.org/2011/02/10-ua-minutes.html

Summary of Action Items
[NEW] ACTION: jallan to rewrite 2.9.1 ier for next week. [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action03]
[NEW] ACTION: JAllan to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action02]
[NEW] ACTION: JimA to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action01]
[NEW] ACTION: JR to With JA to consider how multimedia and executable 
requirements in 2.9 might be improved? [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action04]

Attendees

Present
     [Microsoft], +1.512.206.aaaa, JAllan, +1.425.895.aabb, Greg, 
Jeanne, Jan, sharper, phlauke, +1.617.435.aacc, MarkH, Kim
Regrets
Chair
     Jim Allan, Kelly Ford
Scribe
     greg

Contents

     * Topics
          1. Review Media autoplay - beginning of thread 
http://lists.w3.org/Archives/Public/w3c-wai-ua/2011JanMar/0022.html
          2. 2.9.1 Background Image Toggle
          3. 2.9.3 Execution Placeholder
     * Summary of Action Items

<trackbot> Date: 10 February 2011

<JAllan> 
http://www.w3.org/WAI/UA/2011/ED-IMPLEMENTING-UAAG20-20110202/#gl-control-inaccessible-content

<kford> zakim code?

<patrickhlauke> (sorry, code isn't working on the call-in system)

<sharper> member:zakim, ??P3 is member:sharper

<JAllan> patrick try http://www.w3.org/2006/tools/wiki/Zakim-SIP

<JAllan> simon is calling in using it.

<patrickhlauke> can that be done via skype?

<JAllan> no, but you can call in using skype

<JAllan> Mark is using that

<JAllan> patrick, what is your skype name or phone number, Jan will 
conference you in

<patrickhlauke> patrick_h_lauke

<JAllan> scribe: greg
Review Media autoplay - beginning of thread 
http://lists.w3.org/Archives/Public/w3c-wai-ua/2011JanMar/0022.html

Here's the draft Jim sent in email this morning:

AutoPlay

2.9.2 Time-Based Media Load-Only:

The user can load time-based media content such that the first frame

is displayed (if video), but the content is not played until explicit

user request. (Level A)

Intent:

Essentially, autoplay for media is off/paused, until the user

activates 'play'. Prevent media from playing without explicit request

from the user. For example, Uart, a screen reader user, opens a page

with an audio element that starts playing immediately. The user cannot

hear the screen reader because of the noise from the audio element,

and must search through the page to find the 'noisy' element to turn

it off (or pause). Once the screen reader is the sole source of audio

the user can read the page and determine if the audio is important and

choose to play it.

Examples:

1. one could use the same techniques that are used for pop-up blockers

to see if the play() request was from user interaction or a background

script. If isn't from direct user interaction, one could ask the user

to explicitly allow the media to play, perhaps remembering the choice

for the site.

2. playback of a <video> or <audio> element can only be triggered in

response to a user gesture on a touch screen device with no keyboard

(like pop-up blockers). This has caused no end of bug reports because

it is impossible to differentiate script originated "auto play" from

playback triggered by a script after a delay,

3. user global control in the UA, that calls "paused for user

interaction" for all media.

Resources:

1. HTML5 4.8.10.8 Playing the media resource

(http://dev.w3.org/html5/spec/Overview.html#playing-the-media-resource)

Opera is adding support for the HTML5 4.8.10.8 "Paused for user 
interaction" event.

I recommend changing the first sentence of the Intent to make it clear 
it can be opt-in. E.g. "autoplay for media can be off/paused..."

In example 2, taking out the sentence starting "this has caused no end".

Kim suggests adding recommendation of a visual or audible cue.

<JAllan> ACTION: JimA to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action01]

<trackbot> Sorry, couldn't find user - JimA

<JAllan> ACTION: JAllan to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action02]

<trackbot> Created ACTION-503 - Rewrite IER for 2.9.2 for next week Feb 
17 [on Jim Allan - due 2011-02-17].

<JAllan> note: take example out of the intent or reword.
2.9.1 Background Image Toggle

<JAllan> Background Image Toggle:

<JAllan> The user has the global option to hide/show background images. 
(Level A)

In many other SC we changed phrasing about global options to "the user can".

2.9.1 (former 4.9.1) Background Image Toggle: The user can have 
background images hidden or shown. (Level A)

2.9.1 (former 4.9.1) Background Image Toggle: The user can have all 
background images shown or hidden. (Level A)

Intent: It can be difficult for some people to read text or identify 
images when the background is complex or doesn't contrast well with the 
foreground.

Allowing users to disable the display of background images helps ensure 
that foreground content remains easy to read.

This can also help remove distractions, which is important for some users.

This can also help remove purely decorative distractions, which is 
important for some users.

Examples:

<JAllan> 1. If background images are turned off, make available to the 
user associated conditional content.

<JAllan> 2. In CSS, background images may be turned on/off with the 
background and background-image properties ([CSS2], section 14.2.1).

<kford> possible exampe:

<kford> James has a reading disability where he needs text to be clear 
from distractions that are not related to the text. He configures his 
user agent not to load background images and navigates to a web page. 
James then gets only the text from the web page without any images 
interfering with what he is reading.

Add the first example there to the Intent paragraph as: "Because 
background images occasionally convey important information, when their 
display is turned off the user agent should give users access to any 
alternative content associated with them."

<patrickhlauke> HTML doesn't let you define alternate content for 
images, but then again authors following WCAG shouldn't rely on images alone

We'll move Jim's example #2 into the Related Resources.

Question: do we expect user agents to recognize cases where CSS is used 
to place an image behind text, rather than using a background property?

Relevant definitions:

background images

Images that are rendered on the base background.

base background

The background of the content as a whole, such that no content may be 
layered behind it. In graphics applications, the base background is 
often referred to as the canvas.).

<patrickhlauke> i think the css positioned case would be non-trivial / 
difficult to detect

So our SC wording above does not apply to things arranged using CSS, 
only to things set with the background property.

<patrickhlauke> this will only apply to images set as a background. 
there are other ways - such as with css positioning - in which images 
may be placed behind text. these will not be covered...

<JAllan> This checkpoint does not address issues of multi-layered 
renderings and does not require the user agent to change background 
rendering for multi-layer renderings (refer, for example, to the z-index 
property in Cascading Style Sheets, level 2 ([CSS2], section 9.9.1)

<patrickhlauke> ability to force/override soild bg colour for text

Jan suggests that users have the option to, rather than turning off 
background images, have non-transparent backgrounds of a solid color of 
their choice drawn behind text.

That is another approach to getting text to be legible, and would 
address the problem of backgrounds above the canvas, rather than on the 
base background.

Patrick notes some browsers allow the user to specify foreground and 
background colors for text.

This approach would not address the problem of backgrounds providing 
distractions, or obscuring non-text such as lines and borders.

Discussion of whether blinking backgrounds are already covered by the SC 
about time-based media. (Recognized blinking only.)

<mhakkinen> Browsers should also honor user's OS a11y settings for 
foreground/background color of text. Does the OS setting override the UA 
settings?

Jan notes that backgrounds are often used in ways that are required for 
use of the page, so is reluctant to encourage omitting them.

Jim would prefer not to have another SC.

<JAllan> case for background image vs background color

Jan notes that text foreground and background colors are covered in 
1.4.1 Configure Text.

Re Mark's comment, we note that in Windows, the colors specified by the 
user in Control Panel only override author-specified colors if the user 
explicitly requests it.

Jan will write another sentence for the Intent of 1.4.1 Configure Text 
to make this use clear.

I think this is what we have so far:

2.9.1 (former 4.9.1) Background Image Toggle: The user can have all 
background images shown or hidden. (Level A)

Intent:

It can be difficult for some people to read text or identify images when 
the background is complex or doesn't contrast well with the foreground. 
Allowing users to disable the display of background images helps ensure 
that foreground content remains easy to read. This can also help remove 
purely decorative distractions, which is important for some users.

Because background images occasionally convey important information, 
when their display is turned off the user agent should give users access 
to any alternative content associated with them.

This checkpoint does not address issues of multi-layered renderings and 
does not require the user agent to change background rendering for 
multi-layer renderings (refer, for example, to the z-index property in 
Cascading Style Sheets, level 2 ([CSS2], section 9.9.1)

Examples:

James has a reading disability where he needs text to be clear from 
distractions that are not related to the text. He configures his user 
agent not to load background images and navigates to a web page. James 
then gets only the text from the web page without any images interfering 
with what he is reading.

Related Resources:

In CSS, background images may be turned on/off with the background and 
background-image properties ([CSS2], section 14.2.1).

Because background images occasionally convey important information, 
when their display is turned off the user agent should give users access 
to any alternative content associated with them. (At the time of this 
writing, HTML does not support alternative content for background 
images, but this may be supported in other technologies or future versions.)

<JAllan> ACTION: jallan to rewrite 2.9.1 ier for next week. [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action03]

<trackbot> Created ACTION-504 - Rewrite 2.9.1 ier for next week. [on Jim 
Allan - due 2011-02-17].

<Zakim> Jan, you wanted to say I wonder if we might target the 
background of text instead...eg. ability to make the background of text 
a sold, non transparent colour?
2.9.3 Execution Placeholder

2.9.3 (former 4.9.3) Execution Placeholder: The user can render a 
placeholder instead of executable content that would normally be 
contained within an on-screen area (e.g., Applet, Flash), until explicit 
user request to execute. (Level A)

2.9.3 (former 4.9.3) Execution Placeholder: The user can have 
placeholders rendered instead of executable content that would normally 
be contained within an on-screen area (e.g., Applet, Flash), until 
explicit user request to execute. (Level A)

Patrick asks would this cover native video? Jim thinks not, so Patrick 
suggests using word like plug-in or embedded.

2.9.3 (former 4.9.3) Execution Placeholder: The user can have 
placeholders rendered instead of embedded executable content until 
explicit user request to execute. (Level A)

2.9.3 (former 4.9.3) Execution Placeholder: The user can have 
placeholders rendered instead of embedded executable content (e.g. 
applets/plug-ins) until explicit user request to execute. (Level A)

Jan notes these apply to the authors of plug-ins as well as browsers.

Jan suggests combining 2.9.3 Execution Placeholder and 2.9.4 Execution 
Toggle.

They are both Level A.

No, it turns out 2.9.4 Execution Toggle applies to executable content 
that is NOT contained in a specific on-screen area (e.g. Javascript).

Discussion of changing the titles to more clearly differentiate between 
the two.

Jan asks, what would the authors of a Flash player make of 2.9.3 and 2.9.4?

<JAllan> need to clarify that the UA should have the control of what is 
turned on/off/paused

Jan is concerned that even though some users prefer to turn off some 
technologies, he prefers not to "bake in" in this document technologies 
that are not currently accessible.

<JAllan> JR: we have autoplay. stop/play/resume

<JAllan> ...also flash blocker. don't want to get to prescriptive. want 
to stay general to cover new technologies

<JAllan> PL: want flash to load and then start it playing.

<JAllan> JR: should cover all playable items (movies, plugins, etc)

<patrickhlauke> suggestion for 2.9.4 - can we just go with: "Scripting 
toggle: The user can turn on/off the execution of scripts (e.g. 
JavaScript). (Level A)"

<Jan> ACTION: JR to With JA to consider how multimedia and executable 
requirements in 2.9 might be improved? [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action04]

<trackbot> Created ACTION-505 - With JA to consider how multimedia and 
executable requirements in 2.9 might be improved? [on Jan Richards - due 
2011-02-17].

<JAllan> gl: embedded object is the key to making this work
Summary of Action Items
[NEW] ACTION: jallan to rewrite 2.9.1 ier for next week. [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action03]
[NEW] ACTION: JAllan to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action02]
[NEW] ACTION: JimA to rewrite IER for 2.9.2 for next week Feb 17 
[recorded in http://www.w3.org/2011/02/10-ua-minutes.html#action01]
[NEW] ACTION: JR to With JA to consider how multimedia and executable 
requirements in 2.9 might be improved? [recorded in 
http://www.w3.org/2011/02/10-ua-minutes.html#action04]

[End of minutes]
Received on Thursday, 10 February 2011 19:37:40 GMT

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