Navigation Treeview Example - Keyboard navigation breaks when a node is collapsed with expanded children

[casselc]

Example attached. Using keyboard navigation to expand About, expand Facts, collapse About leads to inability to navigate past About using the down arrow until the Facts element is collapsed. Example captured with Edge 107.0.1418.52, also experienced in Firefox 107 on Windows 11.

treeview.issue.mp4

[JAWS-test]

https://www.w3.org/WAI/ARIA/apg/example-index/treeview/treeview-navigation.html

The problem also occurs in Chrome.

And more generally can be formulated: Whenever a closed submenu contains an open submenu, then it is no longer possible to navigate downwards

[mcking65]

To reproduce:

1. Expand about
2. Press down arrow to navigate to Facts
3. Press right arrow to expand facts
4. Press up arrow to focus About
5. Press left arrow to collapse about
6. Press down arrow to navigate to admissions

Expected result: admissions is focused

Actual result: focus does not move when down arrow is pressed

[css-meeting-bot]

The ARIA Authoring Practices (APG) Task Force just discussed Issue 2544 - Bug in treeview navigation.

The full IRC log of that discussion

<jugglinmike> Topic: Issue 2544 - Bug in treeview navigation
<jugglinmike> github: https://github.com//issues/2544
<jugglinmike> Matt_King: I couldn't figure out what the issue was from the text alone
<jugglinmike> jugglinmike: The critical step to reproduce is to open a sub-menu, leave the sub-menu open, and then close the parent. After that, it becomes impossible to navigate to the parent's siblings
<jugglinmike> jugglinmike: This isn't just about the very first item in the list, either. It can be reproduced using the second item in the list, as well
<jugglinmike> Matt_King: I'll write up a more explicit set of steps to reproduce
<jugglinmike> Zakim, end the meeting