Re: [mediaqueries4] - Pointer size/accuracy


Sorry for the previous message. Now once again but more readable ...

10px and 40px are nice values. But if you have full HD on 5 inch (like
HTC one), your pointer size can have over 150px (very thick fingers).
Other users with motoric handicaps (like multiple sclerosis or
spasticity ... or using eyes to move the pointer) can use the web at
moment only by using keys (as I know) because it is too hard to hit
"our usual" links or buttons by using the pointer.

I think, 150px will also be very good in this cases. But this value
can also be to small for 4k displays (in few years)... It's not easy
to look in the future. A "pointer-accuracy-max(100px)" is flexible...
and can be interesting for game developers (I think so).

The three lexical values are ok for me.

Best regards

2013/4/17 Tab Atkins Jr. <>
> On Tue, Apr 16, 2013 at 12:44 AM, Robert Kk <> wrote:
> > Querying for pointer can be very usable. But it is not exact enough for
> > me...
> >
> > When I use an android mobile with a resolution higher the 400dpi I can draw
> > many things on the view port. But it will not be very usable for the user.
> > His pointer is in real live about 1cm2 and on the viewport over 150px. On a
> > desktop|notebook I have a small resolution (like 1280px or 1024px) but a
> > very exact pointer. I can click on a 5x5 pixel field....
> >
> > For accessibility reasons it can be also good to know, how exact a user can
> > click. Some people can not hit small fields at all. Other must hard try to
> > do it.
> >
> > For smartphones we can get a solution like zoom-in on ambiguous clicks (like
> > in chorme). But we must click two times. Real good responsive design should
> > be able to scale the size of action fields based on pointer size info.
> >
> > My submission is: to use (alternatively) numerical values to recognize how
> > exact a user can click.
> I don't see in your examples any good reasons to need more than two
> levels of accuracy.  Can you explain in more detail a situation where
> you'd need 3 or more accuracy levels?
> While it's not explained in the draft, "fine" generally means your
> pointing targets should be at least 10px wide, while "course" means at
> least 40px wide.  I think Florian has noted in the past that it might
> be reasonable to expose a "very-coarse" value, if someone can show
> that they're developing for a device where targets that are 40px or so
> wide are still too small to accurately hit.
> (Exposing precise parameter values is sometimes an anti-pattern, as
> authors then have to guess what the boundaries of exact categories
> are.  Providing the semantic categories up-front can be an important
> and useful simplification.)
> ~TJ

Received on Thursday, 2 May 2013 17:20:41 UTC