[TCLCORE] Update - tka11y/

[Kevin W. <kw...@co...>]

Hi all,

I've received quite a bit of feedback on TIP 733, screen reader support 
for Tk. Thank you. I wanted to provide an update on how I am taking 
action on the input:

1. Language issues / macOS: I have committed a fix that appears to 
address the issue. Please test and let me know if it works.

2. Adding "set" command prefixes to balance out "get" - done.

3. Verbalizing each keypress and prior word in text/entry widgets - In 
process.

4. Wrong error on progress bars - Need to investigate further. The 
intended behavior at this point for active progress bars is simply to 
return "busy" as the value to indicate it is running. If we are getting 
"0.0," does that mean it is inactive?

5. Microsoft Narrator support - Mixed results. Narrator now correctly 
reads button labels. But overall, support for Narrator is proving very 
difficult to implement. After spending months perfecting the Microsoft 
Active Accessibility implementation, which works very well, I do not 
want to have to reinvent the wheel with a full UI Automation 
implementation to support Narrator. After a lot of work, I have settled 
on using the LegacyIAccessible pattern for UIA, which theoretically 
allows MSAA data to drive UIA queries. However, there are significant 
differences in some aspects of the two API's, and the impedance mismatch 
may make it difficult to provide robust support for Narrator. I 
understand that this is the screen reader bundled with Windows, but 
Narrator generally is regarded as inferior to NVDA and JAWS, the two 
major apps in this area. I will keep working on this, but ultimately may 
have to defer perfection in this area to someone who might have more 
expertise with these API's.

6. Crash reports in test suite - on my to-do list once Narrator is 
addressed.

Let me know if you have any questions.

Thanks,

Kevin