Report accurate state of * lock keys

[boppreh]

Report accurate state of * lock keys

[boppreh]

https://msdn.microsoft.com/en-us/library/ms646301(VS.85).aspx

http://jwilk.net/software/python-keyboardleds

[glitchassassin]

Taking a poke at this tonight to see what it will take. The Windows piece looks easy.

On OSX, caps lock is the only relevant "lock" as num/scroll don't actually have corresponding keyboard states.

The xset command does identify num lock state, e.g. with xset q | grep LED, at least on OSX and I believe on Linux as well. But I'll play around with the keyboardleds sample and try to poll the device itself instead to see if that will work reliably.

edit: xset is installed with XQuartz and isn't part of the standard OSX distribution, so this is not a viable solution on non-Linux platforms.

[glitchassassin]

Incidentally, investigating this, I've discovered that the current code for OSX doesn't actually toggle the capslock state - it just functions like a shift modifier. A quirk of the API, there's probably another way to actually toggle the state for the device.

[glitchassassin]

Aha. Carbon.GetCurrentKeyModifiers() will do the trick on OSX.

[glitchassassin]

Opened PR #263 to track this work. I have Windows and OSX drafted, and I'm spinning up a Linux VM to test the snippets I've found for Linux.

[glitchassassin]

I was not able to get the keyboardleds sample working consistently in non-TTY terminals (e.g., Gnome Terminal). Instead, I opted to call xset and parse the reported LED Flags. This should work at least for any X-based Linux GUI.