Re: CFC - Target Size (Min)

On 17/03/2021 22:53, Patrick H. Lauke wrote:

> I'd say we should pick an actual desired outcome of either:
> 
> 1) user has a sufficiently large target that they can always confidently 
> hit/activate (suggesting we always want a minimum size); or
> 2) each target has at least a minimum sized exclusion/exclusive area 
> that, if the user taps anywhere within that, they may or may not manage 
> to hit that target but at least they won't run the risk of activating 
> some other target.

Expanding on this, it's probably worth taking a step back and trying to 
see what the SC actually aims to achieve in practice. To my mind at 
least, it's along the lines of:

- a touchscreen user or mouse user needs to be able to activate a target
- they're going to be aiming their finger/mouse to the center of the 
control (or whatever the "thickest" part of the control is, if we 
imagine some weird SVG clickable shape that's not rectangular)
- we want to make sure that there's sufficient clearance in this control 
(at least a 24x24 area, centered around this central/fattest point of 
the control) that, even if they aren't accurate with their finger/mouse, 
they don't risk accidentally triggering something else.

Maybe the point of contention/that I'm not getting is that the SC tries 
to account for the fact that the smaller the target is below 24x24, the 
harder it is for a user to determine the center/where they want to 
tap/click? It does seem (unless I'm getting myself confused), that the 
smaller the target gets below 24x24, the larger the "exclusive 
area"/spacing effectively becomes. Taking a 24x24 target, its overall 
exclusive area is literally 24x24. At the extreme end, a 1x1 target 
needs 23 px spacing on all sides, making its exclusive area 47x47 px. If 
that's intentional, it should be very clearly spelled out as well and 
diagrammed.

Speaking of diagrams, isn't the middle case of Figure 5 in 
https://w3c.github.io/wcag/understanding/target-size-minimum.html a Fail 
rather than a Pass? If we're going from the top of the magnifying glass 
icon to the closest adjacent bit of the underlying picture, which is 
20px away since it butts up against the bottom of the magnifying glass 
control which is 20px tall?)

P
-- 
Patrick H. Lauke

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Received on Thursday, 18 March 2021 00:18:50 UTC