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Native Apps: dealing with auto-updating conten in webviews


From: Detlev Fischer
Date: Sep 23, 2022 1:42AM

In an audit of a native public transport app employing auto-updating
webviews, I am wondering how to deal with the issue that screen reader
users, having moved down a scolling list of available transport services
(blocks with departure time, station, service), suddenly lose their
focus when the webview content updates (every minute). Focus seems to be
reset not to the top of the webview, but to some other service located
at the approximate offset of prior (scrolled) location in the list and
upper viewport edge. (Whether this is determined by the OS or default
behaviour of VoiceOver or some behavior defined by the app, I don't
know.) The result: the screen reader output of the service the user has
moved to is suddenly interrupted by the output of some other service
higher up in the list.

The blind tester does not think it a good idea to have a control to stop
auto-updating (wanting to have the current info as anyone else) - so it
feels odd to fail such content for violation of 2.2.1 "Timing
adjustable" (and demand a control to pause auto-updating). In a sense,
this can be seen as a focus management issue (focus is not restored to
previous location) and thus may be seen to fail 2.4.3 "Focus order", but
I wonder whether in the given implementation it would actually be
possible to restore the focus precisely after the auto-update of content
in a webview. And then, since it is the SR focus that is lost, it may
rather fall under 1.3.2 "Meaningful sequence" - only that the sequence
itself is not the issue here. It actually resembles issues falling under
3.2.1 "On Focus" due to the disorienting behavior, but what happens has
nothing to do with the user activity of focussing.

It may be a behaviour that currently fails nothing and has to be
accepted. It could point to a need for something like 3.2.7 "On
Auto-update", with a draft SC text of "When content is updated
automatically, it does not initiate a change of context."  - but I am
not sure whether there would be practical and reliable ways of securing
that (especially in a design context using web views).

So is this behavior a WCAG (or rather EN 301 549 clause 11) failure? (I
know WCAG is for web, not native.) An if so, what SC do you see failing?

Any input would be greatly appreciated.

Detlev Fischer
(Testkreis is now part of DIAS GmbH)

Mobil +49 (0)157 57 57 57 45

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