Add support for the HID Protocol.

[CrazyH2]

Summary of changes

This PR adds a new protocol called Hid which works over BLE and USB.
Other protocols can't be used over BLE which this aims to solve.

Closes 1693

Pull Request Checklist

• HID protocol added.
• HID protocol documented.

[user202729]

If I understood correctly this is just copy pasted from the plugin https://github.com/dnaq/plover-machine-hid/blob/main/plover_machine_hid.py (with the goal to make it available by default in Plover).

Technically nothing wrong (the original repository uses MIT license which allows code to be used in HID)

The motivation is to use a custom protocol over Bluetooth to allow using the standard keyboard… but this may be better off just implementing keyboard selection into Plover in the first place.

#1187

[petercpark]

I support this PR. Let's get this merged!

[dnaq]

This PR needs adding the hidapi libraries to the release files as well for it to work.

[user202729]

The possible problem with merging it here is whether it would be more convenient for @dnaq / @lynn to maintain it here compared to the original repository.

Plus if we merge it here it would be best for the original repository to have a disclaimer like "archived, refer to Plover main repository"

[morinted]

What about adding the plugin to the default plugins and shipping it with releases? Same effect, but keeps the code ownership and parallel development intact?

[dnaq]

Sounds like a perfectly good plan, then the only thing to do in mainline plover would be to make sure hidapi is bundled in the release images (and also to make sure that the machine type is defined so we can set a default keymap).

[morinted]

Yes, if I remember correctly, that was the original plan. I was having trouble bundling HID with the Mac release—someone would need to take that on.

[lynn]

You'll also want to copy over hid_option.py, so that you can configure things like repeat delay from the Plover UI. It'll look like this:

[petercpark]

Yes, if I remember correctly, that was the original plan. I was having trouble bundling HID with the Mac release—someone would need to take that on.

@morinted I have a Mac, is there any way I can help?