RE: Enabling Zoom on Mobile Devices

Gregg,
See my comments below marked as [jda].

Jonathan

On Jan 15, 2015, at 8:37 PM, Jonathan Avila <jon.avila@ssbbartgroup.com<mailto:jon.avila@ssbbartgroup.com>> wrote:

Gregg, go to m.wjla.com<http://m.wjla.com/> on an iPhone.    The page when viewed on the phone contains this meta tag.
<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=0">

See a discussion of this setting below or anywhere else on the web.  This is a very common setting for reasons discussed in the thread.
http://stackoverflow.com/questions/6397748/whats-the-point-of-meta-viewport-user-scalable-no-in-the-google-maps-api



The page works fine with the magnify feature on IOS.    just went there and zoomed to 800%.       (with and without voiceover)

(you can’t  pinch-zoom the page but you can three finger zoom it to what looks like 800%. )

[jda] I do not consider three finger zoom to be a user agent zoom feature as discussed in SC 1.4.4.  Three finger zoom is a platform feature that is not part of the user agent.


This raises an interesting question though.
Are access features that are built into a browser considered AT  or just universal design?
[jda] IMO generally universal design but it depends on the target audience per the WCAG definition and notes on AT.

Are access features built into an OS that has a built in browser considered AT or UD?
[jda] IMO I consider them assistive technology based on the definition of AT in WCAG because they are targeted to specific audiences.

I have always considered access features that are built in as UD and access features that you must buy separately and install would be AT.     At least for the context of this discussion.
[jda] With that approach Narrator and Windows Magnifier would not be assistive technology and neither would VoiceOver, switch control, assistive touch or three finger zoom – Talkback wouldn’t be either.  Saying these items are not assistive technology has far reaching consequences.  G142 says that IE6 can’t be used to meet the sufficient technique – if Windows Magnifier which has been part of the Windows OS since XP can be used to magnify page content then g142 could be met by the Windows XP provided magnifier – I don’t agree with that in regards to WCAG.    In the land of CVAA sure – platform level features are like third party technologies that can be used to meet the functional requirements I agree.

Some definitions of AT call anything that would be used to offset a persons impairments  so that they don’t experience a disability — (or experience less of a disability) — as being at.  So a pencil, and a lazy susan, and   lever door handles are all AT.   This was done to allow broad funding of things to help a person.    So are computers and any web page and a typewriter or word processor (for those who can’t handwrite) etc.  And that clearly is not the meaning of AT in this discussion.      So there are many definitions of AT.      So I don’t want to get into a discussion about all of them.

[jda] We should look to the definition of assistive technology in WCAG.

From WCAG: assistive technology (as used in this document)
hardware and/or software that acts as a user agent, or along with a mainstream user agent, to provide functionality to meet the requirements of users with disabilities that go beyond those offered by mainstream user agents

[jda] The three finger zoom goes beyond the zoom that is offered in mainstream agents.  It:

·          magnifies the whole screen not just the web page contents.  This may include the on-screen keyboard, address bar, etc.

·         Offers additional features such as tracking focus

·         Offers features such as lens magnification


Note 2: Assistive technologies often communicate data and messages with mainstream user agents by using and monitoring APIs.
[jda] This is true to some extent with Three finger Zoom as it follows focus using the frame information and tracks caret.  It has accessibility API level functions that indicate whether it is on/off, etc.

Note 3: The distinction between mainstream user agents and assistive technologies is not absolute. Many mainstream user agents provide some features to assist individuals with disabilities. The basic difference is that mainstream user agents target broad and diverse audiences that usually include people with and without disabilities.  Assistive technologies target narrowly defined populations of users with specific disabilities.

[jda] My point exactly, the zoom feature targets a large audience of people with and without disabilities while the three finger zoom feature is not targeted at a large audience but is targeted at people with low vision.

[jda] More to my point, three finger zoom requires three fingers.  It is not targeted to a large audience or people with motor impairments.  Pinch zoom can be activated with one finger double tap and is available to people with motor impairments.   This helps to separate out the two types of Zoom – Three finger Zoom is designed for a specific population that has the ability to use three fingers despite it being clunky.

But it think you raise some interesting practices that I think may be violations of the SC.   Not necessarily on mobile devices like the iPhone — where you do have a zoom/magnify feature that works fine on all these pages,  but on regular browsers where fixing boundaries or position of images or blocks could cause the page to be non-functional (or semi-non-functional) when the browser zoom is applied.    I think that might be a violation if it does this for all major browsers and the fixed position cannot be turned off by the user. (without needing to reprogram the page or stack style sheets etc that is beyond the typical user).







For another different but related issue visit www.cnn.com<http://www.cnn.com/> on an iPhone.  You will see that the site does enlarge but fixed positioned portions of the page cause the magnified main area of the page content to be very small.  While in this case you can technically get to everything and it would appear to pass, however, I can envision situations where some fixed positioned content might prevent access to the zoomed page because it overlaps when magnified to 200%.






Best Regards,

Jonathan


--
Jonathan Avila
Chief Accessibility Officer
SSB BART Group
jon.avila@ssbbartgroup.com<mailto:jon.avila@ssbbartgroup.com>

703-637-8957 (o)
Follow us: Facebook<http://www.facebook.com/#%21/ssbbartgroup> | Twitter<http://twitter.com/#%21/SSBBARTGroup> | LinkedIn<http://www.linkedin.com/company/355266?trk=tyah> | Blog<http://www.ssbbartgroup.com/blog> | Newsletter<http://eepurl.com/O5DP>

From: Gregg Vanderheiden [mailto:gregg@raisingthefloor.org]
Sent: Thursday, January 15, 2015 8:14 PM
To: Jonathan Avila
Cc: Mike Elledge; GLWAI Guidelines WG org
Subject: Re: Enabling Zoom on Mobile Devices

The zoom feature has nothing to do with the site.

the web page has no idea that it is being zoomed.   Think of it as using a magnifying glass.   There is simply nothing that the web page can do to keep you from using a magnifying glass — or a  mobile zoom feature on the phone.

You wrote:
The zoom feature in Safari on iOS for example does not function when user scaling is blocked so as a person with a visual impairment I am prevented from zooming in on the page with browser zoom.

I know of no way to block the zoom feature.    I don’t know what you mean by ‘scaling’  but I never mentioned scaling.  I’m talking about zoom or magnify.
You cannot block magnify/zoom that I know of — so you cannot fail the SC.

Can you show me a page (send me a URL) of any page that you think has magnification blocked?
I’ll give it a try.    There is always a chance that I am wrong… so willing to look if you think you have something that can block a magnification function.   don’t see how it can be done but willing to look.

Thanks

gregg

On Jan 15, 2015, at 5:44 PM, Jonathan Avila <jon.avila@ssbbartgroup.com<mailto:jon.avila@ssbbartgroup.com>> wrote:

>  Also, please note that the normal ZOOM feature in all browsers is sufficient to meet this requirement.   It is therefore virtually impossible today to not meet this SC unless you either

Greg, I have to disagree, if a site designed for mobile blocks user scaling then how can I use the browser zoom feature.  The zoom feature in Safari on iOS for example does not function when user scaling is blocked so as a person with a visual impairment I am prevented from zooming in on the page with browser zoom.  Can you please explain how this does not fail WCAG – the situation described above is assuming they don’t have another in-page or apple-system-xxx font techniques as discussed earlier..

In my experience most mobile browsers do not have a zoom capability when user scaling is turned off.   Only a few offer an option to override the setting.  IMO there is an accessibility support issue on mobile for this success criteria – there is not sufficient support in browser to override the setting and therefore it’s a failure.

Jonathan

--
Jonathan Avila
Chief Accessibility Officer
SSB BART Group
jon.avila@ssbbartgroup.com<mailto:jon.avila@ssbbartgroup.com>

703-637-8957 (o)
Follow us: Facebook<http://www.facebook.com/#%21/ssbbartgroup> | Twitter<http://twitter.com/#%21/SSBBARTGroup> | LinkedIn<http://www.linkedin.com/company/355266?trk=tyah> | Blog<http://www.ssbbartgroup.com/blog> | Newsletter<http://eepurl.com/O5DP>

From: CAE-Vanderhe [mailto:gregg@raisingthefloor.org]
Sent: Thursday, January 15, 2015 6:05 PM
To: Mike Elledge
Cc: GLWAI Guidelines WG org
Subject: Re: Enabling Zoom on Mobile Devices

the width does not determine the enlargement.

with responsive design you can have a fixed width and be able to enlarge the content 300% or more.

Also, please note that the normal ZOOM feature in all browsers is sufficient to meet this requirement.   It is therefore virtually impossible today to not meet this SC unless you either

  1.  find some way to shrink your text to the same degree that someone zooms the browser  so that it doesn’t change size as you zoom’
  2.  you create content that can ONLY be viewed by a certain browser and that browser has no zoom.


The problems being cited in the other posts are assuming things that are not required by WCAG.


Gregg




On Jan 15, 2015, at 2:08 PM, Mike Elledge <melledge@yahoo.com<mailto:melledge@yahoo.com>> wrote:

Hi All--

Is it required under WCAG 2.0 AA that users can enlarge mobile sites to 200%? The question came up during our monthly accessibility forum, and I haven't been able to find anything about it online.

Apparently it is not uncommon for designers to set a fixed width for Responsive Web Designs, which, it seems to me, would be a violation of 1.4.4.

Your thoughts?

Mike