Re: Comments on the discussion about target size and accidental activation (was Re: Minutes: AGWG meeting April 4, 2017)

On 04/04/2017 19:56, John Foliot wrote:

> To that, I remain concerned that we are in effect mandating a very
> specific page element size to designers, rather than supporting a basic
> principle (all targets should be large enough to activate via touch
> input).

So how would you define "large enough" other than by giving a size?

> ​Next,
>  (and I know you've pointed this to me before) I have
> ​additional
> concerns over referencing a W3C Working Draft that has not yet reached
> consensus and Rec status, which is where things
> ​ appear to​
> stand with the Media Queries Working Draft (which
> ​seems
> to be in flight as
> well, https://drafts.csswg.org/mediaqueries-4/#pointer).

And once again, we're not referencing the technology, we're referencing 
the human-readable definition of what "coarse" and "fine" pointers are. 
If you're worried about that, we can wholesale copy the definition. 
We're not relying on Media Queries Level 4 here, only on the way they 
described what a coarse and fine pointer are.

> I'll also note
> that this Draft has some things to note about "accessibility" and how
> UI's and User Agents may deal with the concept of course and fine pointers:
>
>     For accessibility reasons, even on devices whose pointing device can
>     be described as fine
>     <https://drafts.csswg.org/mediaqueries-4/#valdef-media-pointer-fine>, the
>     UA may give a value of coarse
>     <https://drafts.csswg.org/mediaqueries-4/#valdef-media-pointer-coarse> or none
>     <https://drafts.csswg.org/mediaqueries-4/#valdef-media-pointer-none> to
>     this media query, to indicate that the user has difficulties
>     manipulating the pointing device accurately or at all.
>
>
> If I am to understand that correctly, the notion of "Fine" pointer may
> or may-not be universally supported, which suggests to me another can of
> worms if we try and build upon media-queries and pointer properties.

As we're not relying on the technology (though you may wish to reference 
it in one of the non-normative techniques), this point is mostly moot 
for the normative SC.

> Finally, how will we square the issue with native inputs and other
> "clickable" elements that currently do not meet the minimum?

By native I assume you mean "unstyled"? Authors that wish to comply with 
the proposed SC will have to explicitly style things (in terms of size) 
to ensure they match the required size.

> What about native
> on-screen 'virtual' keyboards - does each letter on the keyboard need to
> be a minimum of 44 px square?

We are not concerned with native in the sense of browser UI. The same 
way we don't talk about "how can we square our requirement for 
accessible web content with the fact that browser X's interface is not 
accessible?"

Whether UA/OS developers follow their own human interface guidance or 
not, or whether their native controls would pass the web content 
accessibility guidelines, is arguably none of our concern?

P
-- 
Patrick H. Lauke

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Received on Tuesday, 4 April 2017 19:10:21 UTC