RE: Enabling Zoom on Mobile Devices

OK, so you have baseline code conformance, e.g. if you unilaterally disable zoom you are not sufficient for some combinations of browsers.  If you for some odd reason built that to be browser aware, so it would allow zoom for some agents and disable it for others—which I can’t think of a rationale for, you could possibly be sufficient.  Just out of curiosity what would the rationale for disallowing overriding of the zoom setting in code be for a browser creator?



Allen Hoffman
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From: Jonathan Avila [mailto:jon.avila@ssbbartgroup.com]
Sent: Friday, January 16, 2015 9:12 AM
To: Katie Haritos-Shea GMAIL; 'Gregg Vanderheiden'
Cc: 'Mike Elledge'; 'GLWAI Guidelines WG org'
Subject: RE: Enabling Zoom on Mobile Devices


Ø  When I go this page/site, m.wjla.com, on an Android device though – it zooms in and out just fine.

In this case Chrome on Android has a “force enable zoom” option that when turned on will allow pinch zoom to work.  So in that user agent the technique is accessibility supported.  However, Firefox on Android blocks pinch zoom when userscale is set to no and I am not aware of a setting to override it.  In addition, I notice that the text size feature in Firefox also appears to be blocked when the viewport userscale is set to no.  As Alistair noted – sites have user agent detection and so different code may be present or not on different platforms.

So, yes, there is an accessibility support issue when it comes to mobile. But no, I don’t consider this a user agent bug – just as you wouldn’t consider assistive technology that doesn’t support ARIA as an AT bug.  But IMO a sufficient technique such as G142 couldn’t be used for mobile sites that are intended for iOS because the technique does not pass the check.  Yes, you could argue that you met the success criteria some other way – you could argue that for every success criteria -- but when it comes done to the conformance requirements the issue would rear its head and site could not conform unless the technologies relied upon were narrowed – such as in an internally within an organization.

Jonathan

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From: Katie Haritos-Shea GMAIL [mailto:ryladog@gmail.com]
Sent: Friday, January 16, 2015 7:54 AM
To: Jonathan Avila; 'Gregg Vanderheiden'
Cc: 'Mike Elledge'; 'GLWAI Guidelines WG org'
Subject: RE: Enabling Zoom on Mobile Devices

Jonathan,

JA wrote: Gregg, go to 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">

When I go this page/site, m.wjla.com, on an Android device though – it zooms in and out just fine.

So doesn’t that make it not an author problem, but rather a mobile browser user agent (on a specific device) support problem?



* katie *

Katie Haritos-Shea
Senior Accessibility SME (WCAG/Section 508/ADA/AODA)

Cell: 703-371-5545 | ryladog@gmail.com<mailto:ryladog@gmail.com> | Oakton, VA | LinkedIn Profile<http://www.linkedin.com/in/katieharitosshea/> | Office: 703-371-5545

From: Jonathan Avila [mailto:jon.avila@ssbbartgroup.com]
Sent: Thursday, January 15, 2015 9:37 PM
To: Gregg Vanderheiden
Cc: Mike Elledge; GLWAI Guidelines WG org
Subject: RE: Enabling Zoom on Mobile Devices

Gregg, go to 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


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


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Jonathan Avila
Chief Accessibility Officer
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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

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Jonathan Avila
Chief Accessibility Officer
SSB BART Group
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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