steam: init with option to install adwaita theme

This adds the steam module and its adwaitaForSteam.enable option which
installs Adwaita for Steam with the Stylix color palette. Note that
Adwaita for Steam is installed directly on the host system using an
activation script.

This is a slightly modified version of the code linked to in
danth#551 (comment) by
@reedrw.

modules/steam/custom.mustache

@@ -0,0 +1,80 @@
+:root {
+  /* The main accent color and the matching text value */
+  --adw-accent-bg-rbg: {{base0D-rgb-r}}, {{base0D-rgb-g}}, {{base0D-rgb-b}};
+  --adw-accent-fg-rbg: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-accent-rgb: {{base0D-rgb-r}}, {{base0D-rgb-g}}, {{base0D-rgb-b}};
+
+  /* destructive-action buttons */
+  --adw-destructive-bg-rgb: {{base08-rgb-r}}, {{base08-rgb-g}}, {{base08-rgb-b}};
+  --adw-destructive-fg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-destructive-rgb: {{base08-rgb-r}}, {{base08-rgb-g}}, {{base08-rgb-b}};
+
+  /* Levelbars, entries, labels and infobars. These don't need text colors */
+  --adw-success-bg-rgb: {{base0B-rgb-r}}, {{base0B-rgb-g}}, {{base0B-rgb-b}};
+  --adw-success-fg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-success-rgb: {{base0B-rgb-r}}, {{base0B-rgb-g}}, {{base0B-rgb-b}};
+
+  --adw-warning-bg-rgb: {{base0E-rgb-r}}, {{base0E-rgb-g}}, {{base0E-rgb-b}};
+  --adw-warning-fg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-warning-fg-a: 0.8;
+  --adw-warning-rgb: {{base0E-rgb-r}}, {{base0E-rgb-g}}, {{base0E-rgb-b}};
+
+  --adw-error-bg-rgb: {{base08-rgb-r}}, {{base08-rgb-g}}, {{base08-rgb-b}};
+  --adw-error-fg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-error-rgb: {{base08-rgb-r}}, {{base08-rgb-g}}, {{base08-rgb-b}};
+
+  /* Window */
+  --adw-window-bg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-window-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+
+  /* Views - e.g. text view or tree view */
+  --adw-view-bg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-view-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+
+  /* Header bar, search bar, tab bar */
+  --adw-headerbar-bg-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-headerbar-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+  --adw-headerbar-border-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-headerbar-backdrop-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-headerbar-shade-rgb: 0, 0, 0;
+  --adw-headerbar-shade-a: 0.9;
+
+  /* Split pane views */
+  --adw-sidebar-bg-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-sidebar-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+  --adw-sidebar-backdrop-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-sidebar-shade-rgb: 0, 0, 0;
+  --adw-sidebar-shade-a: 0.36;
+
+  --adw-secondary-sidebar-bg-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-secondary-sidebar-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+  --adw-secondary-sidebar-backdrop-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-secondary-sidebar-shade-rgb: 0, 0, 0;
+  --adw-secondary-sidebar-shade-a: 0.36;
+
+  /* Cards, boxed lists */
+  --adw-card-bg-rgb: 0, 0, 0;
+  --adw-card-bg-a: 0.08;
+  --adw-card-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+  --adw-card-shade-rgb: 0, 0, 0;
+  --adw-card-shade-a: 0.36;
+
+  /* Dialogs */
+  --adw-dialog-bg-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-dialog-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+
+  /* Popovers */
+  --adw-popover-bg-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-popover-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+  --adw-popover-shade-rgb: {{base01-rgb-r}}, {{base01-rgb-g}}, {{base01-rgb-b}};
+  --adw-popover-shade-a: 0.36;
+
+  /* Thumbnails */
+  --adw-thumbnail-bg-rgb: {{base00-rgb-r}}, {{base00-rgb-g}}, {{base00-rgb-b}};
+  --adw-thumbnail-fg-rgb: {{base05-rgb-r}}, {{base05-rgb-g}}, {{base05-rgb-b}};
+
+  /* Miscellaneous */
+  --adw-shade-rgb: 0, 0, 0;
+  --adw-shade-a: 0.36;
+}
+

modules/steam/hm.nix

@@ -0,0 +1,39 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.stylix.targets.steam;
+in {
+  options.stylix.targets.steam = {
+    enable = config.lib.stylix.mkEnableTarget "Steam" true;
+    adwaitaForSteam.enable = config.lib.stylix.mkEnableTarget "Adwaita for Steam" false;
+  };
+
+  config = lib.mkIf (config.stylix.enable && cfg.enable) (lib.mkMerge [
+    {
+      # Generic configuration
+    }
+
+    (lib.mkIf cfg.adwaitaForSteam.enable {
+      home.packages = with pkgs; [adwsteamgtk];
+
+      home.activation.adwaitaForSteam = let
+        shellScript = pkgs.writeShellScript "adwaitaForSteam" ''
+          rm -f "$HOME/.cache/AdwSteamInstaller/extracted/custom/custom.css"
+          ${lib.getExe pkgs.adwsteamgtk}  -i
+        '';
+      in
+        config.lib.dag.entryAfter ["writeBoundary" "dconfSettings"] ''
+          run --quiet ${shellScript}
+        '';
+
+      # Use custom.css
+      dconf.settings."io/github/Foldex/AdwSteamGtk".prefs-install-custom-css = true;
+
+      xdg.configFile."AdwSteamGtk/custom.css".source = config.lib.stylix.colors {
+        template = ./custom.mustache;
+        extension = "css";
+      };
+
+    })
+  ]);
+}