# Evince. { config, pkgs, lib, ... }: let cfg = config.programs.evince; in { ###### interface options = { programs.evince = { enable = lib.mkEnableOption "Evince, the GNOME document viewer"; package = lib.mkPackageOption pkgs "evince" { }; }; }; ###### implementation config = lib.mkIf config.programs.evince.enable { environment.systemPackages = [ cfg.package ]; services.dbus.packages = [ cfg.package ]; systemd.packages = [ cfg.package ]; }; }