This looks good to me, is there a reason it is still a draft?

It currently says for toggle buttons
Toggle button not pressed half checked
apart from the negative state bug, I'm asking if that's ok as is or a new state would be better to be consistent with pressed and not pressed of toggle buttons.

Please ensure that you test with how this affects the reporting of "indeterminate progress bars" which may use the same state, but a different role.

We don't want them to be reported as "progress bar half checked".

See implementation of "busy indicator": #13428
and issues:

• Indeterminate Progress bars reported as "half-checked" #10644
• NVDA announces indeterminate progressbar as half checked #13910

This does not effect progress bars as the indeterminate state is fetched using the UIA toggle pattern, which is either on, off, or indeterminate. It's specific to toggle buttons and checkboxes. UIA doesn't seem to have a way to fetch if a progress bar is indeterminate.

Half pressed for toggle sounds good to me. I cannot tell if it conveys the way it looks visually, but conveys the meaning.

@Mazen428, please mark this pull request as ready for review.

I don't have a braille display so can't add or test the state in braille, so if someone could that'd be great

@cary-rowen, would you test this on your braille display?

Answer what you care about first:
Yes, I tested with Seika Notetaker, the checkbox can render three states in braille.

The sample I tested is as follows(Enchantment table checkBox):
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/checkbox

Also, I don't know if it will be off topic.
Still using the sample given above, But with UIA enabled NVDA doesn't report checkbox checked status in time.

NVDA can report the checked state of a checkbox in time when UIA is disabled, but Braille can only have two states, checked or unchecked.

Thank you. Could you test with braille using this WPF application?
Simply unpack the archive and you can find the exe inside the bin folder.
You might need the dot net 6 runtime to run it if it fails to launch.
the app just have 3 state toggle button and a 3 state checkbox.
wpftest.zip
Alternatively, the code is included so you could run it if you have the SDK.

WPF example:

The checkbox works as expected for both speech and Braille. the indeterminate state is represented in Braille with the appropriate symbol for the halfchecked state.
The toggle button reports the three states as expected in speech, but the halfpressed state is represented in braille with the whole state instead of the symbol (half pressed).
Edge with the UIA flag set to Yes:

Checkboxes work as expected for both speech and braille. The half checked checkbox is represented in braille with the appropriate symbol for the halfchecked state.
I also observed that NVDA sometimes fails to report the state change for the checkboxes with UIA enabled, but I believe that should be handled outside this PR.

Ok, I think the half pressed braille state is fixed.
By NVDA not announcing UIA checkbox state, is that with WPF or just chromium UIA?

• Build (for testing PR): https://ci.appveyor.com/api/buildjobs/fr2rrje9iayat84c/artifacts/output/nvda_snapshot_pr13980-26151,cbede09d.exe
• FAIL: System tests. See test results for more information.
• PASS: Translation comments check.
• PASS: Lint check.
• PASS: Unit tests.

See test results for failed build of commit cbede09d0e

By NVDA not announcing UIA checkbox state, is that with WPF or just chromium UIA?
The issue only exists in Edge's web pages.
If you want to reproduce it, you must enable NVDA's UIA support for Edge in Advanced Settings Panel.

I can reproduce this on 2022.2, I'm not sure how to fix it and I agree it should be fixed in another PR.
I've also noticed if you go into focus mode it reports the state changes, so it might be a UIA browse mode state change issue, so it's unrelated to what's done here.

Ok, I think the half pressed braille state is fixed.

Yes it is. Thanks @Mazen428 for your work on this PR. It has also helped me in my journey to understand NVDA internals.

I don't have a braille display so can't add or test the state in braille, so if someone could that'd be great

In the future, testing using Braille Viewer should be sufficient.