services: Add LXQt desktop service.

* gnu/services/desktop.scm (lxqt-desktop-service-type): New variable.
(<lxqt-desktop-configuration>): New record type.
(lxqt-desktop-configuration?): New procedure.
* doc/guix.texi (Desktop Services): Document this.

Co-authored-by: Oleg Pykhalov <go.wigust@gmail.com>

doc/guix.texi

@@ -17606,27 +17606,27 @@ field of an @code{operating-system} declaration (@pxref{operating-system
 Reference, @code{services}}).
 
 Additionally, the @code{gnome-desktop-service-type},
-@code{xfce-desktop-service}, @code{mate-desktop-service-type} and
+@code{xfce-desktop-service}, @code{mate-desktop-service-type},
-@code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
+@code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
-and/or Enlightenment to a system.  To ``add GNOME'' means that system-level
+procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system.  To
-services like the backlight adjustment helpers and the power management
+``add GNOME'' means that system-level services like the backlight adjustment
-utilities are added to the system, extending @code{polkit} and @code{dbus}
+helpers and the power management utilities are added to the system, extending
-appropriately, allowing GNOME to operate with elevated privileges on a
+@code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
-limited number of special-purpose system interfaces.  Additionally,
+elevated privileges on a limited number of special-purpose system interfaces.
-adding a service made by @code{gnome-desktop-service-type} adds the GNOME
+Additionally, adding a service made by @code{gnome-desktop-service-type} adds
-metapackage to the system profile.  Likewise, adding the Xfce service
+the GNOME metapackage to the system profile.  Likewise, adding the Xfce
-not only adds the @code{xfce} metapackage to the system profile, but it
+service not only adds the @code{xfce} metapackage to the system profile, but
-also gives the Thunar file manager the ability to open a ``root-mode''
+it also gives the Thunar file manager the ability to open a ``root-mode'' file
-file management window, if the user authenticates using the
+management window, if the user authenticates using the administrator's
-administrator's password via the standard polkit graphical interface.
+password via the standard polkit graphical interface.  To ``add MATE'' means
-To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
+that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
-appropriately, allowing MATE to operate with elevated privileges on a
+to operate with elevated privileges on a limited number of special-purpose
-limited number of special-purpose system interfaces.  Additionally,
+system interfaces.  Additionally, adding a service of type
-adding a service of type @code{mate-desktop-service-type} adds the MATE
+@code{mate-desktop-service-type} adds the MATE metapackage to the system
-metapackage to the system profile.  ``Adding Enlightenment'' means that
+profile.  ``Adding Enlightenment'' means that @code{dbus} is extended
-@code{dbus} is extended appropriately, and several of Enlightenment's binaries
+appropriately, and several of Enlightenment's binaries are set as setuid,
-are set as setuid, allowing Enlightenment's screen locker and other
+allowing Enlightenment's screen locker and other functionality to work as
-functionality to work as expected.
+expected.
 
 The desktop environments in Guix use the Xorg display server by
 default.  If you'd like to use the newer display server protocol
@@ -17694,6 +17694,24 @@ The MATE package to use.
 @end table
 @end deftp
 
+@deffn {Scheme Variable} lxqt-desktop-service-type
+This is the type of the service that runs the @uref{https://lxqt.github.io,
+LXQt desktop environment}.  Its value is a @code{lxqt-desktop-configuration}
+object (see below).
+
+This service adds the @code{lxqt} package to the system
+profile.
+@end deffn
+
+@deftp {Data Type} lxqt-desktop-configuration
+Configuration record for the LXQt desktop environment.
+
+@table @asis
+@item @code{lxqt} (default: @code{lxqt})
+The LXQT package to use.
+@end table
+@end deftp
+
 @deffn {Scheme Variable} enlightenment-desktop-service-type
 Return a service that adds the @code{enlightenment} package to the system
 profile, and extends dbus with actions from @code{efl}.

gnu/services/desktop.scm

@@ -11,6 +11,7 @@
 ;;; Copyright © 2019 Tim Gesthuizen <tim.gesthuizen@yahoo.de>
 ;;; Copyright © 2019 David Wilson <david@daviwil.com>
 ;;; Copyright © 2020 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2020 Reza Alizadeh Majd <r.majd@pantherx.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -53,6 +54,7 @@
   #:use-module (gnu packages suckless)
   #:use-module (gnu packages linux)
   #:use-module (gnu packages libusb)
+  #:use-module (gnu packages lxqt)
   #:use-module (gnu packages mate)
   #:use-module (gnu packages nfs)
   #:use-module (gnu packages enlightenment)
@@ -127,6 +129,11 @@
             mate-desktop-service
             mate-desktop-service-type
 
+            lxqt-desktop-configuration
+            lxqt-desktop-configuration?
+            lxqt-desktop-service
+            lxqt-desktop-service-type
+
             xfce-desktop-configuration
             xfce-desktop-configuration?
             xfce-desktop-service
@@ -1009,6 +1016,36 @@ system as root from within a user session, after the user has authenticated
 with the administrator's password."
   (service xfce-desktop-service-type config))
 
++
+;;;
+;;; Lxqt desktop service.
+;;;
+
+(define-record-type* <lxqt-desktop-configuration> lxqt-desktop-configuration
+  make-lxqt-desktop-configuration
+  lxqt-desktop-configuration?
+  (lxqt lxqt-package
+        (default lxqt)))
+
+(define (lxqt-polkit-settings config)
+  "Return the list of LXQt dependencies that provide polkit actions and
+rules."
+  (let ((lxqt (lxqt-package config)))
+    (map (lambda (name)
+           ((package-direct-input-selector name) lxqt))
+         '("lxqt-admin"))))
+
+(define lxqt-desktop-service-type
+  (service-type
+   (name 'lxqt-desktop)
+   (extensions
+    (list (service-extension polkit-service-type
+                             lxqt-polkit-settings)
+          (service-extension profile-service-type
+                             (compose list lxqt-package))))
+   (default-value (lxqt-desktop-configuration))
+   (description "Run LXQt desktop environment.")))
+
 
 ;;;
 ;;; X11 socket directory service