Mobile VO does't synchronize DOM focus and virtual cursor

[jessegreenberg]

I just noticed that recent versions of mobile VO don't synchronize DOM focus with the virtual cursor. And I could not find any device settings to change this in accessibility or Safari settings. I couldn't find anything about this in online searches either. This isn't the case for iPad2 with iOS 9.3, but is for iPad Pro with iOS 12.

This means that we generally don't get any focus events with mobile VoiceOver. So we don't see any of our pink focus highlights on this platform, and won't get any special behavior we add to the focus event (like reading an alert when focus lands on something).

The good news is that since PDOM elements are positioned correctly, the black VO focus highlight correctly surrounds sim elements instead of our pink focus highlight.

But this may still create design constraints for us. It would be good to discuss this constraint with the a11y team.

[jessegreenberg]

and won't get any special behavior we add to the focus event (like reading an alert when focus lands on something).

Maybe we should add documentation in "How to instrument a sim with a11y" documents that describe this problem and recommend to generally not add listeners to focus and use aria-describedby instead of aria-live (utteranceQueue) when focus changes?

[jessegreenberg]

recommend to generally not add listeners to focus

This is really unfortunate. Should we send a bug report to Apple?

[jessegreenberg]

We get focus events correctly if we call element.focus(). We just don't get them when reading through content with the virtual cursor. Maybe that isn't so bad.

[jessegreenberg]

After discussing with @emily-phet, an immediate next step is to send a bug report/feature request to apple. This isn't an immediate issue but will be a problem when working on sims with a black background (like molecules-and-light and coulombs-law) because the VoiceOver highlight is black.

[jessegreenberg]

Duplicate now of #138, closing.