WebAIM - Web Accessibility In Mind

E-mail List Archives

Applying 2.5.1 Pointer Gestures to tile sliders in native apps.

for

From: Detlev Fischer
Date: Apr 13, 2023 9:57AM

This is about applying 2.5.1 Pointer Gestures to tile sliders in native
apps.

Very frequently in apps, there is no way to reach tiles in horizontal
sliders that are not in the viewport without what can be considered a
swipe gesture following the 2.5.1 Understanding text (a gesture which
requires an initial directional movement of the pointer). With these
sliders, a (roughly) horizontal movement engages the slider while a
vertical movement would scroll the page instead (vertically). Moving
down-left or down-right would not make the slider follow the pointer -
i.e the gesture has been consumed by the view and  has no effect on the
slider.

This pattern is extremely common: native app examples are Zalando,
Amazon, Ebay, ZDFtivi, and I guess many many more. Usually single
pointer alternatives (like arrows) for activation are absent. Do all
these apps really fail 2.5.1?

This issue is whether the gesture needed really falls into pointer
gestures rather than being classed as a dragging movement (which
incidentally would require similar alternatives for simple tap pointer
input if WCAG 2.2 Success Criterion 2.5.7 Dragging Movements becomes
part of WCAG 2.2).

Differentiating the required gesture from dragging movements is
difficult here, because *any* dragging movement that is more horizontal
than vertical (i.e., not just a movement in the desired direction) does
not scroll the view vertically, but lets the slider follow the
horizontal pointer position in the same way as in dragging movements.
Therefore it is unclear whether tappable controls like arrows are really
required for such slider areas in order to meet 2.5.1 Pointer Gestures.

I'd be very keen to see how others auditing native apps treat this
situation.

best,
Detlev

--
Detlev Fischer
DIAS GmbH
(Testkreis is now part of DIAS GmbH)

Mobil +49 (0)157 57 57 57 45

http://www.dias.de
Beratung, Tests und Schulungen für barrierefreie Websites