kde: enable custom decorations and polish code

modules/kde/hm.nix

@@ -4,27 +4,25 @@
   lib,
   ...
 }:
-
-with config.stylix.fonts;
-with config.lib.stylix.colors;
-
 let
   cfg = config.stylix.targets.kde;
 
+  inherit (config.lib.stylix)
+    colors
+    mkEnableTarget
+    ;
+
   formatValue =
     value:
-    if builtins.isBool value then
-      if value then "true" else "false"
-    else
-      builtins.toString value;
+    if lib.isBool value then if value then "true" else "false" else toString value;
 
   formatSection =
     path: data:
     let
       header = lib.concatStrings (map (p: "[${p}]") path);
       formatChild = name: formatLines (path ++ [ name ]);
       children = lib.mapAttrsToList formatChild data;
-      partitioned = lib.partition builtins.isString children;
+      partitioned = lib.partition lib.isString children;
       directChildren = partitioned.right;
       indirectChildren = partitioned.wrong;
     in
@@ -34,9 +32,9 @@ let
 
   formatLines =
     path: data:
-    if builtins.isAttrs data then
+    if lib.isAttrs data then
       if data ? _immutable then
-        if builtins.isAttrs data.value then
+        if lib.isAttrs data.value then
           formatSection (path ++ [ "$i" ]) data.value
         else
           "${lib.last path}[$i]=${formatValue data.value}"
@@ -58,7 +56,7 @@ let
   # in kebab-case will load when selected manually, but don't work with a
   # look and feel package.
   colorschemeSlug = lib.concatStrings (
-    builtins.filter builtins.isString (builtins.split "[^a-zA-Z]" scheme)
+    lib.filter lib.isString (builtins.split "[^a-zA-Z]" colors.scheme)
   );
 
   colorEffect = {
@@ -70,52 +68,76 @@ let
     IntensityAmount = 0;
   };
 
-  colors = {
-    BackgroundNormal = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-    BackgroundAlternate = "${base01-rgb-r},${base01-rgb-g},${base01-rgb-b}";
-    DecorationFocus = "${base0D-rgb-r},${base0D-rgb-g},${base0D-rgb-b}";
-    DecorationHover = "${base0D-rgb-r},${base0D-rgb-g},${base0D-rgb-b}";
-    ForegroundNormal = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-    ForegroundActive = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-    ForegroundInactive = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-    ForegroundLink = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-    ForegroundVisited = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-    ForegroundNegative = "${base08-rgb-r},${base08-rgb-g},${base08-rgb-b}";
-    ForegroundNeutral = "${base0D-rgb-r},${base0D-rgb-g},${base0D-rgb-b}";
-    ForegroundPositive = "${base0B-rgb-r},${base0B-rgb-g},${base0B-rgb-b}";
+  mkColorTriple =
+    name:
+    lib.concatStringsSep "," (
+      map (color: colors."${name}-rgb-${color}") [
+        "r"
+        "g"
+        "b"
+      ]
+    );
+
+  mkColorMapping =
+    num:
+    let
+      hex = "base0${lib.toHexString num}";
+    in
+    {
+      name = hex;
+      value = mkColorTriple hex;
+    };
+
+  colors' = lib.listToAttrs (map mkColorMapping (lib.range 0 15));
+
+  kdecolors = with colors'; {
+    BackgroundNormal = base00;
+    BackgroundAlternate = base01;
+    DecorationFocus = base0D;
+    DecorationHover = base0D;
+    ForegroundNormal = base05;
+    ForegroundActive = base05;
+    ForegroundInactive = base05;
+    ForegroundLink = base05;
+    ForegroundVisited = base05;
+    ForegroundNegative = base08;
+    ForegroundNeutral = base0D;
+    ForegroundPositive = base0B;
   };
 
   colorscheme = {
     General = {
       ColorScheme = colorschemeSlug;
-      Name = scheme;
+      Name = colors.scheme;
     };
 
     "ColorEffects:Disabled" = colorEffect;
     "ColorEffects:Inactive" = colorEffect;
 
-    "Colors:Window" = colors;
-    "Colors:View" = colors;
-    "Colors:Button" = colors;
-    "Colors:Tooltip" = colors;
-    "Colors:Complementary" = colors;
-    "Colors:Selection" = colors // {
-      BackgroundNormal = "${base0D-rgb-r},${base0D-rgb-g},${base0D-rgb-b}";
-      BackgroundAlternate = "${base0D-rgb-r},${base0D-rgb-g},${base0D-rgb-b}";
-      ForegroundNormal = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      ForegroundActive = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      ForegroundInactive = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      ForegroundLink = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      ForegroundVisited = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-    };
-
-    WM = {
-      activeBlend = "${base0A-rgb-r},${base0A-rgb-g},${base0A-rgb-b}";
-      activeBackground = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      activeForeground = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
-      inactiveBlend = "${base03-rgb-r},${base03-rgb-g},${base03-rgb-b}";
-      inactiveBackground = "${base00-rgb-r},${base00-rgb-g},${base00-rgb-b}";
-      inactiveForeground = "${base05-rgb-r},${base05-rgb-g},${base05-rgb-b}";
+    "Colors:Window" = kdecolors;
+    "Colors:View" = kdecolors;
+    "Colors:Button" = kdecolors;
+    "Colors:Tooltip" = kdecolors;
+    "Colors:Complementary" = kdecolors;
+    "Colors:Selection" =
+      kdecolors
+      // (with colors'; {
+        BackgroundNormal = base0D;
+        BackgroundAlternate = base0D;
+        ForegroundNormal = base00;
+        ForegroundActive = base00;
+        ForegroundInactive = base00;
+        ForegroundLink = base00;
+        ForegroundVisited = base00;
+      });
+
+    WM = with colors'; {
+      activeBlend = base0A;
+      activeBackground = base00;
+      activeForeground = base05;
+      inactiveBlend = base03;
+      inactiveBackground = base00;
+      inactiveForeground = base05;
     };
   };
 
@@ -138,7 +160,7 @@ let
   };
 
   lookAndFeelDefaults = {
-    kwinrc."org.kde.kdecoration2".library = "org.kde.breeze";
+    kwinrc."org.kde.kdecoration2".library = cfg.decorations;
     plasmarc.Theme.name = "default";
 
     kdeglobals = {
@@ -212,7 +234,7 @@ let
   kdeglobals = {
     KDE.LookAndFeelPackage = makeImmutable "stylix";
 
-    General = rec {
+    General = with config.stylix.fonts; rec {
       font = makeImmutable "${sansSerif.name},${toString sizes.applications},-1,5,50,0,0,0,0,0";
       fixed = makeImmutable "${monospace.name},${toString sizes.terminal},-1,5,50,0,0,0,0,0";
       desktopFont = makeImmutable "${sansSerif.name},${toString sizes.desktop},-1,5,50,0,0,0,0,0";
@@ -251,36 +273,44 @@ let
   # might be installed, and look there. The ideal solution would require
   # changes to KDE to make it possible to update the wallpaper through
   # config files alone.
-  activator = pkgs.writeShellScriptBin "stylix-set-kde-wallpaper" ''
+  activator' = pkgs.writeShellScriptBin "stylix-activate-kde" ''
     set -eu
-    global_path() {
+    get_exe() {
       for directory in /run/current-system/sw/bin /usr/bin /bin; do
         if [[ -f "$directory/$1" ]]; then
           printf '%s\n' "$directory/$1"
           return 0
         fi
       done
-
+      echo "Skipping `$1`: command not found"
       return 1
     }
 
-    if wallpaper_image="$(global_path plasma-apply-wallpaperimage)"; then
+    if wallpaper_image="$(get_exe plasma-apply-wallpaperimage)"; then
       "$wallpaper_image" "${themePackage}/share/wallpapers/stylix"
-    else
-      echo "Skipping plasma-apply-wallpaperimage: command not found"
     fi
 
-    if look_and_feel="$(global_path plasma-apply-lookandfeel)"; then
+    if look_and_feel="$(get_exe plasma-apply-lookandfeel)"; then
       "$look_and_feel" --apply stylix
-    else
-      echo "Skipping plasma-apply-lookandfeel: command not found"
     fi
   '';
-
-  activateDocs = "https://stylix.danth.me/options/hm.html#stylixtargetskdeservice";
+  activator = lib.getExe activator';
 in
 {
-  options.stylix.targets.kde.enable = config.lib.stylix.mkEnableTarget "KDE" true;
+  options.stylix.targets.kde = {
+    enable = mkEnableTarget "KDE" true;
+
+    decorations = lib.mkOption {
+      type = lib.types.str;
+      default = "org.kde.breeze";
+      description = ''
+        The library for the window decorations theme. Decorations other than default
+        `org.kde.breeze` may not be compatible with stylix. To view all available
+        values, see the `library` key in the `org.kde.kdecoration2` section of `$HOME/.config/kwinrc`
+        after imperatively applying the window decoration via the System Settings app.
+      '';
+    };
+  };
 
   config =
     lib.mkIf
@@ -290,10 +320,9 @@ in
           packages = [ themePackage ];
 
           # This activation entry will run the theme activator when the homeConfiguration is activated
-          # Note: This only works in an already running Plasma session.
           activation.stylixLookAndFeel = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
-            ${lib.getExe activator} || verboseEcho \
-              "KDE theme setting failed. See `${activateDocs}`"
+            ${activator} || verboseEcho \
+              "Stylix KDE theme setting failed. This only works in a running Plasma session."
           '';
         };
 
@@ -305,7 +334,7 @@ in
           configFile."autostart/stylix-activator.desktop".text = ''
             [Desktop Entry]
             Type=Application
-            Exec=${lib.getExe activator}
+            Exec=${activator}
             Name=Stylix Activator
             X-KDE-AutostartScript=true
           '';