Remapping Capslock on Wayland

Here’s how to setup remapping CAPSLOCK on Arch/Wayland/Sway using the Dual Function Keys plugin from the Interception Tools library.

More specifically, I’m remapping CAPSLOCK to act as

• ESC when pressed/tapped by itself
• and as the Windows key if in combination with another key

I have the windows key setup as a modifier in the Sway window manager, to be able to position any application.

And I use ESC in vim to exit insert mode.

Previously, I used xcape on X11, however this won’t work on Wayland, and probably won’t be in the near future as per this discussion. Thankfully by intercepting udevmon you can create a mapping that works on both X11 and Wayland.

Setup Dual-function-keys

Installation

1. First install the plugin

sudo pacman -S interception-dual-function-keys

Configuration

2. Create the mapping file i.e in sudo nvim /etc/interception/dual-function-keys/capslock.yaml

• find available keycodes in https://raw.githubusercontent.com/torvalds/linux/master/include/uapi/linux/input-event-codes.h

# config for https://gitlab.com/interception/linux/plugins/dual-function-keys#dual-function-keys
# keycodes from https://raw.githubusercontent.com/torvalds/linux/master/include/uapi/linux/input-event-codes.h
 
MAPPINGS:
    # remap capslock
  - KEY: KEY_CAPSLOCK
    # tap capslock for escape
    TAP: KEY_ESC
    # tap capslock for windows key
    HOLD: KEY_LEFTMETA

3. Create the udevmon configuration sudo nvim /etc/interception/udevmon.d/capslock.yaml

• you can the NAME of your keyboard with sudo libinput list-devices | grep "^Device" | grep -i keyboard

- JOB: "intercept -g $DEVNODE | dual-function-keys -c /etc/interception/dual-function-keys/capslock.yaml | uinput -d $DEVNODE"
  DEVICE:
    # name of your keyboard device
    NAME: ".*"
    # NAME: ".*keyboard"
    # NAME: "SONiX USB DEVICE Keyboard"
    # NAME: "AT Translated Set 2 keyboard"

4. Setup udevmon to boot with your system

sudo systemctl start udevmon
sudo systemctl enable udevmon

Now your keypresses should be remapped.

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I got the gist of working with interception-tools from this blog A Guide to Switching From i3 to Sway - by Scott Gilbertson