nixos/lxqt: add options iconThemePackage and extraPackages (#439536)

nixos/modules/services/x11/desktop-managers/lxqt.nix

···
 with lib;
 
 let
-  xcfg = config.services.xserver;
-  cfg = xcfg.desktopManager.lxqt;
+  cfg = config.services.xserver.desktopManager.lxqt;
 
 in
 
···
 
   options = {
 
-    services.xserver.desktopManager.lxqt.enable = mkOption {
-      type = types.bool;
-      default = false;
-      description = "Enable the LXQt desktop manager";
+    services.xserver.desktopManager.lxqt.enable = mkEnableOption "the LXQt desktop manager";
+
+    services.xserver.desktopManager.lxqt.iconThemePackage =
+      lib.mkPackageOption pkgs [ "kdePackages" "breeze-icons" ] { }
+      // {
+        description = "The package that provides a default icon theme.";
+      };
+
+    services.xserver.desktopManager.lxqt.extraPackages = lib.mkOption {
+      type = with lib.types; listOf package;
+      default = [ ];
+      defaultText = lib.literalExpression "[ ]";
+      example = lib.literalExpression "with pkgs; [ xscreensaver ]";
+      description = "Extra packages to be installed system wide.";
     };
 
     environment.lxqt.excludePackages = mkOption {
+      type = with lib.types; listOf package;
       default = [ ];
-      example = literalExpression "[ pkgs.lxqt.qterminal ]";
-      type = types.listOf types.package;
+      defaultText = lib.literalExpression "[ ]";
+      example = lib.literalExpression "with pkgs; [ lxqt.qterminal ]";
       description = "Which LXQt packages to exclude from the default environment";
     };
 
···
     environment.systemPackages =
       pkgs.lxqt.preRequisitePackages
       ++ pkgs.lxqt.corePackages
-      ++ (utils.removePackagesByName pkgs.lxqt.optionalPackages config.environment.lxqt.excludePackages);
+      ++ [ cfg.iconThemePackage ]
+      ++ (utils.removePackagesByName pkgs.lxqt.optionalPackages config.environment.lxqt.excludePackages)
+      ++ cfg.extraPackages;
 
     # Link some extra directories in /run/current-system/software/share
     environment.pathsToLink = [ "/share" ];
···
     programs.gnupg.agent.pinentryPackage = mkDefault pkgs.pinentry-qt;
 
     # virtual file systems support for PCManFM-QT
-    services.gvfs.enable = true;
+    services.gvfs.enable = mkDefault true;
 
     services.upower.enable = config.powerManagement.enable;