Manage AltGr on Windows

[Geobert]

Fixes #820

Tested with local build of Yazi and Broot

[fnuttens]

Tested with local build of Helix, this solves related issues (helix-editor/helix#5718 and helix-editor/helix#7129) 🎉

Thank you so much for your work @Geobert!

[TimonPost]

Do you have a link to some documentation that this is the correct way to check if altgr is pressed? Like some resource from Microsoft, since I have difficulties looking up the spec for this and no keyboard to try on.

[Geobert]

Do you have a link to some documentation that this is the correct way to check if altgr is pressed? Like some resource from Microsoft, since I have difficulties looking up the spec for this and no keyboard to try on.

Hi, thanks for looking at this.

I don’t have such spec unfortunately, but this is from one of MS team https://github.com/microsoft/Terminal/blob/660d31ac522186e615ec243de2a434c273464828/src/terminal/input/terminalInput.cpp#L400-L419

and other sources quoted in the issue have similar code to manage AltGr :)

Let me know if you need more :)

[joshka]

This is also related to #917 and comments in #685 (comment)

[joshka]

Is this the wrong thing to do for non-AltGr enabled keyboards? Will this swallow the specific combination of Alt+Ctrl keys?

[Geobert]

It might for combinations using Right alt+Ctrl keys I guess