remap capslock

common/default.nix

@@ -36,6 +36,7 @@ if !builtins.elem vacuModuleType expectedModuleTypes then builtins.throw "error:
     ./minimal-nixos.nix
     ./acmeDependencies.nix
     ./nix-on-droid.nix
+    ./remapCapsLock.nix
   ];
   options = {
     vacu.rootCAs = mkOption { type = types.listOf types.str; };

common/remapCapsLock.nix

@@ -0,0 +1,35 @@
+{
+  pkgs,
+  lib,
+  config,
+  vacuModuleType,
+  ...
+}:
+let
+  inherit (lib) mkOption types;
+in
+lib.optionalAttrs (vacuModuleType == "nixos") {
+  options.vacu.enableCapsLockRemap = mkOption {
+    type = types.bool;
+    default = config.vacu.systemKind == "desktop";
+  };
+  config = lib.mkIf config.vacu.enableCapsLockRemap {
+    # https://discourse.nixos.org/t/best-way-to-remap-caps-lock-to-esc-with-wayland/39707/6
+    services.interception-tools =
+    let
+      itools = pkgs.interception-tools;
+      itools-caps = pkgs.interception-tools-plugins.caps2esc;
+    in
+    {
+      enable = true;
+      plugins = [ itools-caps ];
+      # requires explicit paths: https://github.com/NixOS/nixpkgs/issues/126681
+      udevmonConfig = pkgs.lib.mkDefault ''
+        - JOB: "${itools}/bin/intercept -g $DEVNODE | ${itools-caps}/bin/caps2esc -m 1 | ${itools}/bin/uinput -d $DEVNODE"
+          DEVICE:
+            EVENTS:
+              EV_KEY: [KEY_CAPSLOCK, KEY_ESC]
+      '';
+    };
+  };
+}