feat: add theme

shamelessly stolen from github:jnsgruk/nixos-config

Signed-off-by: Lander Van den Bulcke <landervandenbulcke@gmail.com>

lib/theme/colours.nix

@@ -0,0 +1,61 @@
+rec {
+  colours = rec {
+    inherit (catppuccin-macchiato)
+      pink
+      red
+      yellow
+      green
+      ;
+    inherit (catppuccin-macchiato) subtext0 subtext1 text;
+    inherit (catppuccin-macchiato) overlay0 overlay1 overlay2;
+    inherit (catppuccin-macchiato) surface0 surface1 surface2;
+
+    accent = darkBlue;
+    black = catppuccin-macchiato.crust;
+    white = catppuccin-macchiato.rosewater;
+    lightPink = catppuccin-macchiato.flamingo;
+    lightRed = catppuccin-macchiato.maroon;
+    orange = catppuccin-macchiato.peach;
+    cyan = catppuccin-macchiato.teal;
+    blue = catppuccin-macchiato.sapphire;
+    darkBlue = catppuccin-macchiato.blue;
+    lightBlue = catppuccin-macchiato.sky;
+    purple = catppuccin-macchiato.mauve;
+    lightPurple = catppuccin-macchiato.lavender;
+    bg = catppuccin-macchiato.base;
+    bgDark = catppuccin-macchiato.mantle;
+  };
+
+  catppuccin-macchiato = {
+    rosewater = "#f4dbd6";
+    flamingo = "#f0c6c6";
+    pink = "#f5bde6";
+    mauve = "#c6a0f6";
+    red = "#ed8796";
+    maroon = "#ee99a0";
+    peach = "#f5a97f";
+    yellow = "#eed49f";
+    green = "#a6da95";
+    teal = "#8bd5ca";
+    sky = "#91d7e3";
+    sapphire = "#7dc4e4";
+    blue = "#8aadf4";
+    lavender = "#b7bdf8";
+
+    subtext0 = "#a5adcb";
+    subtext1 = "#b8c0e0";
+    text = "#cad3f5";
+
+    overlay0 = "#6e738d";
+    overlay1 = "#8087a2";
+    overlay2 = "#939ab7";
+
+    surface0 = "#363a4f";
+    surface1 = "#494d64";
+    surface2 = "#5b6078";
+
+    base = "#24273a";
+    crust = "#181926";
+    mantle = "#1e2030";
+  };
+}

lib/theme/default.nix

@@ -0,0 +1,69 @@
+{
+  pkgs,
+  ...
+}:
+let
+  inherit ((import ./colours.nix)) colours;
+  libx = import ./lib.nix { inherit (pkgs) lib; };
+in
+rec {
+  inherit (libx) hexToRgb;
+  inherit colours;
+
+  catppuccin = {
+    flavor = "macchiato";
+    accent = "blue";
+    size = "standard";
+  };
+
+  wallpaper = ./wallpapers/norway.png;
+
+  gtkTheme = {
+    name = "catppuccin-macchiato-blue-standard";
+    package = pkgs.catppuccin-gtk.override {
+      size = catppuccin.size;
+      variant = catppuccin.flavor;
+      accents = [ catppuccin.accent ];
+    };
+  };
+
+  qtTheme = {
+    name = "Catppuccin-Macchiato-Blue";
+    package = pkgs.catppuccin-kvantum.override {
+      variant = "Macchiato";
+      accent = "Blue";
+    };
+  };
+
+  iconTheme = rec {
+    name = "Papirus-Dark";
+    package = pkgs.papirus-icon-theme;
+    iconPath = "${package}/share/icons/${name}";
+  };
+
+  cursorTheme = {
+    name = "Adwaita";
+    package = pkgs.adwaita-icon-theme;
+    size = 24;
+  };
+
+  fonts = {
+    default = {
+      name = "Inter";
+      package = pkgs.inter;
+      size = "11";
+    };
+    iconFont = {
+      name = "Inter";
+      package = pkgs.inter;
+    };
+    monospace = {
+      name = "MesloLGSDZ Nerd Font Mono";
+      package = pkgs.nerdfonts.override { fonts = [ "Meslo" ]; };
+    };
+    emoji = {
+      name = "Joypixels";
+      package = pkgs.joypixels;
+    };
+  };
+}

lib/theme/lib.nix

@@ -0,0 +1,68 @@
+{ lib, ... }:
+with lib;
+rec {
+  # color-related functions
+
+  # convert rrggbb hex to #rrggbb
+  x = c: "#${c}";
+
+  # convert #rrggbb -> r, g, b
+  hexToRgb =
+    c:
+    let
+      r = toString (hexToDec (__substring 1 2 c));
+      g = toString (hexToDec (__substring 3 2 c));
+      b = toString (hexToDec (__substring 5 2 c));
+      res = "${r}, ${g}, ${b}";
+    in
+    res;
+
+  # functions copied from https://gist.github.com/corpix/f761c82c9d6fdbc1b3846b37e1020e11
+  # convert a hex value to an integer
+  hexToDec =
+    v:
+    let
+      hexToInt = {
+        "0" = 0;
+        "1" = 1;
+        "2" = 2;
+        "3" = 3;
+        "4" = 4;
+        "5" = 5;
+        "6" = 6;
+        "7" = 7;
+        "8" = 8;
+        "9" = 9;
+        "a" = 10;
+        "b" = 11;
+        "c" = 12;
+        "d" = 13;
+        "e" = 14;
+        "f" = 15;
+        "A" = 10;
+        "B" = 11;
+        "C" = 12;
+        "D" = 13;
+        "E" = 14;
+        "F" = 15;
+      };
+      chars = stringToCharacters v;
+      charsLen = length chars;
+    in
+    foldl (a: v: a + v) 0 (imap0 (k: v: hexToInt."${v}" * (pow 16 (charsLen - k - 1))) chars);
+
+  pow =
+    let
+      pow' =
+        base: exponent: value:
+        # FIXME: It will silently overflow on values > 2**62 :(
+        # The value will become negative or zero in this case
+        if exponent == 0 then
+          1
+        else if exponent <= 1 then
+          value
+        else
+          (pow' base (exponent - 1) (value * base));
+    in
+    base: exponent: pow' base exponent base;
+}