Send different key codes for Tab and Ctrl+I (READ: support modifyOtherKeys)

[ghillb]

Description of the new feature/enhancement

When using ms-terminal, Tab and Ctrl+I send the same key codes. This makes it impossible to map them differently, for example in vim or nvim (which support this functionality: neovim/neovim#17932 (comment)).

If ms-terminal sent different key codes (like for example kitty or alacritty terminal), then it would be possible to map these keys to different functionalities in software running inside the terminal. This would enhance user experience and make it easier to migrate from the aforementioned terminals.

Proposed technical implementation details (optional)

[zadjii-msft]

Okay this sounds like we just need to support modifyOtherKeys. There was previous discussion in

• Terminal should support libtickit style input #8719
• Add keyboard protocol support (the kitty one) #11509

From the docs

When modifyOtherKeys is set, ordinary keys may be sent as escape
sequences:

• When modifyOtherKeys is set to 1, only the alt- and meta-modifiers
  apply. For example, alt-Tab sends CSI 2 7 ; 3 ; 9 ~ (the second
  parameter is "3" for alt, and the third parameter is the ASCII value
  of tab, "9").
• When modifyOtherKeys is set to 2, all of the modifiers apply. For
  example, shift-Tab sends CSI 2 7 ; 2 ; 9 ~ rather than CSI Z (the
  second parameter is "2" for shift).

[matthewgrossman]

Does anyone have a workaround for this problem in the interim?

My concrete issue: I have different mappings for <TAB> and <C-i> in neovim. In macOS, Kitty can differentiate just fine, but in Terminal on Windows (ubuntu wsl2) it seems to view them as the same input.

[AH-Merii]

Hi @zadjii-msft,

As the comment above mentioned, is there a temporary workaround that we can use while this issue is being worked on?

[zadjii-msft]

You could probably manually add a sendInput action in the Terminal settings, bound to ctrl+I, that sends ~ some escape sequence ~, and then configure your editor to be bound to that escape sequence instead of just C-i.

What ~ some escape sequence ~ actually is would depend on the rest of your config, I'd reckon. I'm not super familiar with keybinding editing for neovim, so I don't really have a good end-to-end recommendation here, I'm afraid.

[AH-Merii]

No worries, thanks for pointing me in the right direction, I will look into it!

[AntonC9018]

It doesn't work by default for me on alacritty. In fact, it straight up ignores those key combos altogether.

If anyone has a working hack to fix this, making all of these keys be sent correctly, please share. It's a really draining issue for me