nix/module/Wayland.nix

{
  pkgs,
  lib,
  config,
  ...
}:
with lib;
let
  cfg = config.module.desktop.wayland;
in
{
  options = {
    module.desktop.wayland.enable = mkEnableOption "Wayland.";
  };

  config = {
    programs.xwayland.enable = true;

    environment = {
      systemPackages = with pkgs; [
        wl-clipboard # CLI clipboard support.
      ];

      variables = {
        # Compatibility variables.
        ECORE_EVAS_ENGINE = "wayland_egl";
        ELM_ENGINE = "wayland_egl";
        GDK_BACKEND = "wayland";
        MOZ_ENABLE_WAYLAND = "1";
        QT_QPA_PLATFORM = "wayland-egl;wayland;xcb";
        QT_WAYLAND_DISABLE_WINDOWDECORATION = "1";
        SAL_USE_VCLPLUGIN = "gtk3";
        SDL_VIDEODRIVER = "wayland";
        _JAVA_AWT_WM_NONREPARENTING = "1";
      };
    };
  };
}