Optionally play sounds when toggling screen curtain

[leonardder]

Note: filed against beta.

Link to issue number:

Fixes #10602
Closes #10476

Summary of the issue:

There is currently no audible indication of the screen curtain turning on/off due to a configuration profile change.

Description of how this pull request fixes the issue:

Add screen curtain on/off sounds, provided by Andre Louis. Also make sure that the screen curtain is only activated once (i.e not reinitialized) when enabling permanently.

Testing performed:

Tested enabling/disabling the curtain using a config profile and the global command script.

Known issues with pull request:

While this strictly spoken does not fix #10476, I think having the ability to enable screen curtain in one profile while disabling it in another has too much benefits to justify making it a global setting. Specifying what settings should be global is a different issue.

Change log entry:

None needed

[josephsl]

Eh? Sorry, but this review approval didn’t count. I’ll take care of it in just a few moments. Thanks. From: Ozancan Karataş <notifications@github.com> Sent: Saturday, December 14, 2019 6:56 PM To: nvaccess/nvda <nvda@noreply.github.com> Cc: Subscribed <subscribed@noreply.github.com> Subject: Re: [nvaccess/nvda] Optionally play sounds when toggling screen curtain (#10611) @OzancanKaratas approved this pull request. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#10611?email_source=notifications&email_token=AB4AXEHX2D6PDWIMFQWD4BDQYWMC3A5CNFSM4JZUWSQKYY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCPGZPZQ#pullrequestreview-332240870> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB4AXEHGD54MBGRLLUP5EV3QYWMC3ANCNFSM4JZUWSQA> .

[josephsl]

Hi,

Two important things, both in user guide:

1. Vision/screen curtain section: can you add a brief note about sounds to indicate screen curtain toggle?
2. In line 1399: screen curtain is misspelled.

A minor thing about Andre's sounds: the "on" sound is heard predominantly from the left side. I think we should compensate for that somehow (or it could be my hearing or my headset).

Thanks.

[josephsl]

Thanks.

[davidacm]

is just my mind or is the sound (ON / OFF) not clear enough?
I can identify it, but it could be difficult for people with hearing loss.