test and improve screen reader accessibility in Preferences

[ronso0]

there was a heads up on Zulip from a blind DJ again:
https://mixxx.zulipchat.com/#narrow/stream/113295-controller-mapping/topic/Problems.20using.20anMC4000.20controller.20with.20Mixxx

[ronso0 (ronso0)]

Findings with Orca in Mixxx 2.3 beta on Ubuntu Studio 20.04

opening Preferences, pressing Tab

=========
Live Broadcasting: (* focused widget [spoken text])
* Help [pushbutton]
* Restore Defaults []
* Apply []
* Cancel []
* Okay []
* (appearantly, now the entire inner Pref page has focus (up/down cause scroll moves)
(pressing Tab a few times, no feedback)
= stuck. neither Tab nor Shift+Tab move the focus

So IMO a necessary first step is to make sure all pages can be navigated with Tab and arrow keys. From a first look, I think this involves restructuring some page layouts by removing all not strictly necessary wrappers, but also review pages that dynamically populated in C++.

Then we need to assign tabstops to generate a predictable Tab order (this would help ALL users btw).

After that, let's look into https://doc.qt.io/qt-5/qaccessible.html ...

[ronso0 (ronso0)]

navigation in Broadcasting is fixed in https://github.com/mixxxdj/mixxx/pull/3156

[ronso0 (ronso0)]

well, have to say my test wasn't very efficient, mostly due to Orca being unreliable I guess.
Some widgets are described, some aren't. When I reverse the cycle with Shift+Tab, some widgets are described while others described earlier aren't anymore.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/10000