11.stylix/docs/src/tricks.md

Tips and tricks

Adjusting the brightness and contrast of a background image

If you want to use a background image for your desktop but find it too bright or distracting, you can use the imagemagick package to dim the image, or adjust its brightness and contrast to suit your preference.

Here's an example Nix expression that takes an input image, applies a brightness/contrast adjustment to it, and saves the result as a new image file:

{ pkgs, ... }:

let
  inputImage = ./path/to/image.jpg;
  brightness = -30;
  contrast = 0;
  fillColor = "black"
in
{
  stylix.image = pkgs.runCommand "dimmed-background.png" { } ''
    ${pkgs.imagemagick}/bin/convert "${inputImage}" -brightness-contrast ${brightness},${contrast} -fill ${fillColor} $out
  '';
}

Dynamic wallpaper generation based on selected theme

With imagemagick, you can also dynamically generate wallpapers based on the selected theme. Similarly, you can use a template image and repaint it for the current theme.

{ pkgs, ... }:

let
  theme = "${pkgs.base16-schemes}/share/themes/catppuccin-latte.yaml";
  wallpaper = pkgs.runCommand "image.png" {} ''
        COLOR=$(${pkgs.yq}/bin/yq -r .base00 ${theme})
        COLOR="#"$COLOR
        ${pkgs.imagemagick}/bin/magick convert -size 1920x1080 xc:$COLOR $out
  '';
in {
  stylix = {
    image = wallpaper;
    base16Scheme = theme;
  };
}

Which is neatly implemented as a single function in lib.stylix.pixel:

{ pkgs, config, ... }:

{
  stylix = {
    image = config.lib.stylix.pixel "base0A";
    base16Scheme = "${pkgs.base16-schemes}/share/themes/catppuccin-latte.yaml";
  };
}

Completely disabling some stylix targets

Nixpkgs module system sometimes works in non-intuitive ways, e.g. parts of the configuration guarded by lib.mkIf are still being descended into. This means that every loaded (and not enabled) module must be compatible with others - in the sense that every option that is mentioned in the disabled parts of the configuration still needs to be defined somewhere.

Sometimes that can be a problem, when your particular configuration diverges enough from what stylix expects. In that case you can try stubbing all the missing options in your configuration.

Or in a much clearer fashion you can just disable offending stylix targets by adding the following disableModules line next to importing stylix itself:

imports = [ flake.inputs.stylix.nixosModules.stylix ];
disabledModules = [ "${flake.inputs.stylix}/modules/<some-module>/nixos.nix" ];