Add Swaylock overlay ✨

Fixes #8

flake.nix

@@ -61,6 +61,7 @@
           ./modules/plymouth
           ./modules/qutebrowser.nix
           ./modules/sway.nix
+          ./modules/swaylock.nix
           ./modules/vim.nix
           (import ./stylix/palette.nix {
             inherit (self.packages.${pkgs.system}) palette-generator;

modules/swaylock.nix

@@ -0,0 +1,46 @@
+{ config, lib, ... }:
+
+with config.lib.stylix.colors;
+
+let
+  inside = base01-hex;
+  ring = base05-hex;
+  text = base05-hex;
+  positive = base0B-hex;
+  negative = base08-hex;
+
+in {
+  # mkAfter is important for those who use nixpkgs-wayland,
+  # as otherwise it could overwrite our wrapper
+  nixpkgs.overlays = lib.mkAfter [
+    (final: prev: {
+      swaylock = final.writeShellScriptBin "swaylock" ''
+        exec ${prev.swaylock}/bin/swaylock \
+          --image ${config.stylix.image} \
+          --scaling fill \
+          --inside-color ${inside} \
+          --inside-clear-color ${inside} \
+          --inside-caps-lock-color ${inside} \
+          --inside-ver-color ${inside} \
+          --inside-wrong-color ${inside} \
+          --key-hl-color ${positive} \
+          --layout-bg-color ${inside} \
+          --layout-border-color ${ring} \
+          --layout-text-color ${text} \
+          --line-uses-inside \
+          --ring-color ${ring} \
+          --ring-clear-color ${negative} \
+          --ring-caps-lock-color ${ring} \
+          --ring-ver-color ${positive} \
+          --ring-wrong-color ${negative} \
+          --separator-color 00000000 \
+          --text-color ${text} \
+          --text-clear-color ${text} \
+          --text-caps-lock-color ${text} \
+          --text-ver-color ${text} \
+          --text-wrong-color ${text} \
+          "$@"
+      '';
+    })
+  ];
+}