Semantics polish meta bug

[abarth]

• Crashes
  • Resuming accessibility while stocks is up crashes stocks #2333
• Modality
  • Accessibility: When menu is up, you can still navigate the stuff behind it #1705
  • Expose modality to iOS accessibility #3821
  • Overlay hit detection reports hits on obscured elements #3819
• AX doesn't work if already enabled
• Be able to turn off Once _semanticsEnabled, no way to disable them (can't turn off accessibility) #3342
• hasSemantics -> isSemanticBoundary
• Move TestSemanticsClient to flutter_test
• SemanticsNode.addListener needs a "remove" companion
• Value for adjustable

[goderbauer]

@abarth @Hixie Do you remember what was meant by these points:

• AX doesn't work if already enabled
• Move TestSemanticsClient to flutter_test (TestSemanticsClient doesn't have any hits in the code base)
• Value for adjustable

[goderbauer]

I am closing this bug for now as I can't put it in the new accessibility project as is. Feel free to open new bugs for the unresolved issues and label them with accessibility.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.