Re: Graphics contrast comments overview

1.3 covers Adaptable. It measures the ability of the content to be adapted 
without losing meaning, hence the need for:
programmatic determinability for any content that has sequence, 
relationships and information visually shown
a non-reliance on sensory characteristics (that can't be adapted)

1.4 covers Distinguishable. It ensures that information that is intended 
to be distinguishable continues to be so for users with reduced abilities 
to distinguish. It covers:
contrast
use of color
images of text
text resizing (which I'll admit has always seemed to me like 1.3)

There may come a time when a user who cannot distinguish at the minimums 
we specify needs to use an AT or otherwise transform the content using the 
requirements in 1.3 to adapt the content. But the point of Graphics 
contrast is to ensure more content is distinguishable. That's why it comes 
in the same section as Contrast (Minimum).

In short, 1.3 and 1.4 SCs are complementary and address different use 
cases.

Michael Gower
IBM Accessibility
Research

1803 Douglas Street, Victoria, BC  V8T 5C3
gowerm@ca.ibm.com
voice: (250) 220-1146 * cel: (250) 661-0098 *  fax: (250) 220-8034



From:   Sailesh Panchang <sailesh.panchang@deque.com>
To:     James Nurthen <james.nurthen@oracle.com>, WCAG <w3c-wai-gl@w3.org>
Cc:     Alastair Campbell <acampbell@nomensa.com>, Michael Gower 
<michael.gower@ca.ibm.com>, Jonathan Avila <jon.avila@levelaccess.com>
Date:   2017-11-22 06:50 PM
Subject:        Re: Graphics contrast comments overview



As per the note to SC 1.4.1, one needs to take recourse to Guideline
1.3 which I interpret to mean 1.3.1 here when a presentation mechanism
other than color is relied to convey info-relationships.
So if contrast is used to distinguish the state of an element, is it
not covered by 1.3.1 requiring programmatic determination?
Thanks and regards,
Sailesh


On 11/15/17, James Nurthen <james.nurthen@oracle.com> wrote:
>
> On Nov 15, 2017, 8:46 AM -0800, Michael Gower 
<michael.gower@ca.ibm.com>,
> wrote:
>> There is no language requiring a contrast minimum between the states
>> themselves. I would really like that to at least be captured in the
>> Understanding doc, if it can't be part of the SC, because being unable 
to
>> differentiate between states is as much of a problem as not being able 
to
>> differentiate between controls.
> I always fail this on 1.4.1 Use of Color: Color is not used as the only
> visual means of conveying information, indicating an action, prompting a
> response, or distinguishing a visual element. (Level A)
>
> If the ratio is 3:1 or greater then it is no longer color alone (hue and
> lightness) so no longer fails 1.4.1. As such I don’t think this needs to 
be
> in this SC.
>
>> The same concern applies for disabled versus enabled controls.
>>
>> Speaking of disabled controls, we exclude disabled controls from 
contrast
>> considerations completely, but I've always felt that if a designer 
bothers
>> to put a disabled element in the UI, that element's visual presence is
>> important, and should be discernible with some minimum contrast (even 
if
>> it is reduced). Every designer balks when I say 'Okay, if it's not
>> important, why not remove it from your design entirely until it is
>> active?'
>>
>> At the least, can we work disabled controls into the AAA SC discussed?
>> Alastair, I'd be happy to help try to craft that.
>>
>> Michael Gower
>> IBM Accessibility
>> Research
>>
>> 1803 Douglas Street, Victoria, BC  V8T 5C3
>> gowerm@ca.ibm.com
>> voice: (250) 220-1146 * cel: (250) 661-0098 *  fax: (250) 220-8034
>>
>>
>>
>> From:        Alastair Campbell <acampbell@nomensa.com>
>> To:        Jonathan Avila <jon.avila@levelaccess.com>, WCAG
>> <w3c-wai-gl@w3.org>
>> Date:        2017-11-15 08:28 AM
>> Subject:        Re: Graphics contrast comments overview
>>
>>
>>
>> Hi Jon,
>>
>> > if the author uses a border to communicate the role of something
>> > then the aspect has to meet the contrast requirements.
>>
>> Agree. Also, I noticed we missed out the default-appearance exception, 
so
>> I’ve updated that to say:
>> “Visual information used to indicate state for active user interface
>> components, except where the appearance of the component is determined 
by
>> the user agent and not modified by the author.”
>>
>> > It doesn't require an author provide that affordance if they didn't. 
So
>> > if I choose to make a piece of text blue and have it function like a
>> > button nothing needs to be done other than the contrast of the blue 
text
>> > in the non-focused state or non-pressed state of that button.
>>
>> Agree.
>>
>> > If I use a solid background to make something look like a button then 
I
>> > have to make sure the edge of the background has sufficient contrast
>> > from the surrounding pixels outside of the focused or pressed state.
>>
>> Agree.
>>
>> > If I have multiple buttons with some in pressed and others in
>> > non-pressed states the difference between the colors used for the
>> > pressed states need to have a 3:1 ratio as well.
>>
>> Agree. It is also worth considering the ‘adjacent’ aspect, if buttons 
are
>> not immediately adjacent, then they do not have to contrast with each
>> other.
>>
>> > Focus indicators need to provide 3:1 contrast as well.  Is that 
right?
>>
>> Yes, although with-what depends on what they are adjacent to.
>>
>> Cheers,
>>
>> -Alastair
>>
>>
>>
>>
>


-- 
Sailesh Panchang
Principal Accessibility Consultant
Deque Systems Inc
Phone 703-225-0380 ext 105
Mobile: 571-344-1765