repo: move everything gtk into modules

This is mostly so that applications like ReGreet, which are managed by
NixOS instead of HM, can also use the same GTK settings. It reduces
repeating code by a lot and allows changing themes way more easily now.

home/programs/fuzzel.nix

@@ -15,7 +15,7 @@
         font = "monospace:size=14";
       };
       colors = let
-        inherit (inputs.basix.schemeData.base16.${nixosConfig.theme.scheme}) palette;
+        inherit (inputs.basix.schemeData.base16.${nixosConfig.style.scheme}) palette;
       in {
         background = "${palette.base00}ff";
         text = "${palette.base05}ff";

home/programs/gtk.nix

@@ -1,12 +1,11 @@
 {
   pkgs,
   config,
+  nixosConfig,
   ...
 }: {
   home.pointerCursor = {
-    package = pkgs.bibata-cursors;
-    name = "Bibata-Modern-Classic";
-    size = 24;
+    inherit (nixosConfig.style.cursorTheme) name package size;
     gtk.enable = true;
     x11.enable = true;
   };
@@ -30,21 +29,11 @@
     gtk2.configLocation = "${config.xdg.configHome}/gtk-2.0/gtkrc";
 
     iconTheme = {
-      name = "Papirus-Dark";
-      package = pkgs.papirus-icon-theme;
+      inherit (nixosConfig.style.gtk.iconTheme) name package;
     };
 
-    theme = let
-      accent = "lavender";
-      variant = "frappe";
-      size = "standard";
-    in {
-      name = "catppuccin-${variant}-${accent}-${size}";
-      package = pkgs.catppuccin-gtk.override {
-        # https://github.com/NixOS/nixpkgs/blob/nixos-23.05/pkgs/data/themes/catppuccin-gtk/default.nix
-        accents = [accent];
-        inherit variant size;
-      };
+    theme = {
+      inherit (nixosConfig.style.gtk.theme) name package;
     };
   };
 }

home/programs/swaybg.nix

@@ -11,7 +11,7 @@
       PartOf = ["graphical-session.target"];
     };
     Service = {
-      ExecStart = builtins.trace nixosConfig.theme.wallpaper "${lib.getExe pkgs.swaybg} -i ${nixosConfig.theme.wallpaper} -m fill";
+      ExecStart = "${lib.getExe pkgs.swaybg} -i ${nixosConfig.style.wallpaper} -m fill";
       Restart = "on-failure";
     };
     Install.WantedBy = ["graphical-session.target"];

home/programs/swaylock.nix

@@ -4,7 +4,7 @@
   nixosConfig,
   ...
 }: let
-  inherit (inputs.basix.schemeData.base16.${nixosConfig.theme.scheme}) palette;
+  inherit (inputs.basix.schemeData.base16.${nixosConfig.style.scheme}) palette;
 in {
   # requires `security.pam.services.swaylock = { };` at the system level or else
   # unlock will not work.

home/terminal/emulators/foot.nix

@@ -11,8 +11,7 @@
         font = "monospace:size=14";
       };
       colors = let
-        inherit (nixosConfig.theme) scheme;
-        schemeData = inputs.basix.schemeData.base16.${scheme};
+        schemeData = inputs.basix.schemeData.base16.${nixosConfig.style.scheme};
       in {
         background = schemeData.palette.base00;
         foreground = schemeData.palette.base05;

hosts/default.nix

@@ -23,13 +23,15 @@
           ../system/services/regreet.nix
           "${mod}/programs/niri"
 
-          self.nixosModules.theme
+          self.nixosModules.style
 
           {
-            theme.wallpaper = lib.mkDefault ../wallpapers/lucy-edgerunners-wallpaper.jpg;
-            theme.scheme = lib.mkDefault "catppuccin-frappe";
+            style = {
+              gtk.enable = true;
+              wallpaper = lib.mkDefault ../wallpapers/lucy-edgerunners-wallpaper.jpg;
+              scheme = lib.mkDefault "catppuccin-frappe";
+            };
           }
-
           {
             home-manager = {
               users.nezia.imports = homeImports.vamos;

modules/default.nix

@@ -1,5 +1,5 @@
 {
   flake.nixosModules = {
-    theme = import ./theme;
+    style = import ./style;
   };
 }

modules/style/default.nix

@@ -0,0 +1,48 @@
+{
+  lib,
+  pkgs,
+  ...
+}: let
+  inherit (lib) mkOption;
+  inherit (lib.types) string path package;
+in {
+  imports = [./gtk.nix];
+  options.style = {
+    scheme = mkOption {
+      description = ''
+        Name of the tinted-scheming color scheme to use.
+      '';
+      type = string;
+      example = lib.literalExpression "catppuccin-frappe";
+    };
+    wallpaper = mkOption {
+      description = ''
+        Location of the wallpaper that will be used throughout the system.
+      '';
+      type = path;
+      example = lib.literalExpression "./wallpaper.png";
+    };
+
+    cursorTheme = {
+      name = mkOption {
+        description = ''
+          Name of the cursor theme.
+        '';
+        default = "Bibata-Modern-Classic";
+      };
+      package = mkOption {
+        type = package;
+        description = ''
+          Package providing the cursor theme.
+        '';
+        default = pkgs.bibata-cursors;
+      };
+      size = mkOption {
+        description = ''
+          Size of the cursor.
+        '';
+        default = 24;
+      };
+    };
+  };
+}

modules/style/gtk.nix

@@ -0,0 +1,66 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  inherit (builtins) pathExists;
+  inherit (lib) mkOption mkEnableOption;
+  inherit (lib.types) package str;
+
+  cfg = config.style.gtk;
+in {
+  options.style.gtk = {
+    enable = mkEnableOption "enable GTK theming options";
+    theme = {
+      name = mkOption {
+        type = str;
+        description = "Name for the GTK theme";
+        default = "catppuccin-frappe-lavender-standard";
+      };
+      package = mkOption {
+        type = package;
+        description = "Package providing the GTK theme";
+
+        default = pkgs.catppuccin-gtk.override {
+          # https://github.com/NixOS/nixpkgs/blob/nixos-23.05/pkgs/data/themes/catppuccin-gtk/default.nix
+          variant = "frappe";
+          accents = ["lavender"];
+          size = "standard";
+        };
+      };
+    };
+    iconTheme = {
+      name = mkOption {
+        type = str;
+        description = "The name for the icon theme that will be used for GTK programs";
+        default = "Papirus-Dark";
+      };
+
+      package = mkOption {
+        type = package;
+        description = "The GTK icon theme to be used";
+        default = pkgs.catppuccin-papirus-folders.override {
+          accent = "lavender";
+          flavor = "frappe";
+        };
+      };
+    };
+  };
+  config = {
+    assertions = [
+      (let
+        themePath = cfg.theme.package + /share/themes + "/${cfg.theme.name}";
+      in {
+        assertion = cfg.enable -> pathExists themePath;
+        message = ''
+          ${toString themePath} set by the GTK module does not exist!
+
+          To suppress this message, make sure that
+          `config.modules.style.gtk.theme.package` contains
+          the path `${cfg.theme.name}`
+        '';
+      })
+    ];
+  };
+}

modules/theme/default.nix

@@ -1,18 +0,0 @@
-{lib, ...}: {
-  options.theme = {
-    scheme = lib.mkOption {
-      description = ''
-        Name of the tinted-scheming color scheme to use.
-      '';
-      type = lib.types.string;
-      example = lib.literalExpression "catppuccin-frappe";
-    };
-    wallpaper = lib.mkOption {
-      description = ''
-        Location of the wallpaper that will be used throughout the system.
-      '';
-      type = lib.types.path;
-      example = lib.literalExpression "./wallpaper.png";
-    };
-  };
-}

system/services/regreet.nix

@@ -1,19 +1,29 @@
 {
-  inputs,
+  lib,
+  pkgs,
   config,
   ...
-}: {
+}: let
+  inherit (lib) mkForce;
+in {
+  environment.systemPackages = [
+    config.style.gtk.theme.package
+    config.style.gtk.iconTheme.package
+    config.style.cursorTheme.package
+  ];
+
   programs.regreet = {
     enable = true;
+    package = pkgs.greetd.regreet;
     cageArgs = [
       "-s"
       "-d"
     ];
     settings = {
-      GTK = let
-        schemeData = inputs.basix.schemeData.base16.${config.theme.scheme};
-      in {
-        application_prefer_dark_theme = schemeData.variant == "dark";
+      GTK = {
+        cursor_theme_name = mkForce config.style.cursorTheme.name;
+        icon_theme_name = mkForce config.style.gtk.iconTheme.name;
+        theme_name = mkForce config.style.gtk.theme.name;
       };
     };
   };