gnu: services: Add MATE desktop service.

* gnu/services/desktop.scm (<mate-desktop-configuration>,
mate-desktop-service-type): New variable.
(mate-desktop-service): New public variable.

* doc/guix.texi (Desktop Services): Document the service.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

doc/guix.texi

@@ -26,7 +26,7 @@ Copyright @copyright{} 2016 Ben Woodcroft@*
 Copyright @copyright{} 2016, 2017 Chris Marusich@*
 Copyright @copyright{} 2016, 2017 Efraim Flashner@*
 Copyright @copyright{} 2016 John Darrington@*
-Copyright @copyright{} 2016 ng0@*
+Copyright @copyright{} 2016, 2017 ng0@*
 Copyright @copyright{} 2016, 2017 Jan Nieuwenhuizen@*
 Copyright @copyright{} 2016 Julien Lepiller@*
 Copyright @copyright{} 2016 Alex ter Weele@*
@@ -12106,7 +12106,7 @@ The @code{(gnu services desktop)} module provides services that are
 usually useful in the context of a ``desktop'' setup---that is, on a
 machine running a graphical display server, possibly with graphical user
 interfaces, etc.  It also defines services that provide specific desktop
-environments like GNOME and XFCE.
+environments like GNOME, XFCE or MATE.
 
 To simplify things, the module defines a variable containing the set of
 services that users typically expect on a machine with a graphical
@@ -12131,9 +12131,10 @@ The @var{%desktop-services} variable can be used as the @code{services}
 field of an @code{operating-system} declaration (@pxref{operating-system
 Reference, @code{services}}).
 
-Additionally, the @code{gnome-desktop-service} and
+Additionally, the @code{gnome-desktop-service},
-@code{xfce-desktop-service} procedures can add GNOME and/or XFCE to a
+@code{xfce-desktop-service} and @code{mate-desktop-service}
-system.  To ``add GNOME'' means that system-level services like the
+procedures can add GNOME, XFCE and/or MATE to a system.
+To ``add GNOME'' means that system-level services like the
 backlight adjustment helpers and the power management utilities are
 added to the system, extending @code{polkit} and @code{dbus}
 appropriately, allowing GNOME to operate with elevated privileges on a
@@ -12144,6 +12145,11 @@ not only adds the @code{xfce} metapackage to the system profile, but it
 also gives the Thunar file manager the ability to open a ``root-mode''
 file management window, if the user authenticates using the
 administrator's password via the standard polkit graphical interface.
+To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
+appropriately, allowing MATE to operate with elevated privileges on a
+limited number of special-purpose system interfaces.  Additionally,
+adding a service made by @code{mate-desktop-service} adds the MATE
+metapackage to the system profile.
 
 @deffn {Scheme Procedure} gnome-desktop-service
 Return a service that adds the @code{gnome} package to the system
@@ -12158,9 +12164,15 @@ file system as root from within a user session, after the user has
 authenticated with the administrator's password.
 @end deffn
 
-Because the GNOME and XFCE desktop services pull in so many packages,
+@deffn {Scheme Procedure} mate-desktop-service
+Return a service that adds the @code{mate} package to the system
+profile, and extends polkit with the actions from
+@code{mate-settings-daemon}.
+@end deffn
+
+Because the GNOME, XFCE and MATE desktop services pull in so many packages,
 the default @code{%desktop-services} variable doesn't include either of
-them by default.  To add GNOME or XFCE, just @code{cons} them onto
+them by default.  To add GNOME, XFCE orMATE, just @code{cons} them onto
 @code{%desktop-services} in the @code{services} field of your
 @code{operating-system}:
 

gnu/services/desktop.scm

@@ -4,6 +4,7 @@
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2016 Sou Bunnbu <iyzsong@gmail.com>
 ;;; Copyright © 2017 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2017 ng0 <ng0@infotropique.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -42,6 +43,7 @@
   #:use-module (gnu packages suckless)
   #:use-module (gnu packages linux)
   #:use-module (gnu packages libusb)
+  #:use-module (gnu packages mate)
   #:use-module (guix records)
   #:use-module (guix packages)
   #:use-module (guix store)
@@ -82,6 +84,11 @@
             gnome-desktop-service
             gnome-desktop-service-type
 
+            mate-desktop-configuration
+            mate-desktop-configuration?
+            mate-desktop-service
+            mate-desktop-service-type
+
             xfce-desktop-configuration
             xfce-desktop-configuration?
             xfce-desktop-service
@@ -817,6 +824,32 @@ rules."
 and extends polkit with the actions from @code{gnome-settings-daemon}."
   (service gnome-desktop-service-type config))
 
+;; MATE Desktop service.
+;; TODO: Add mate-screensaver.
+
+(define-record-type* <mate-desktop-configuration> mate-desktop-configuration
+  make-mate-desktop-configuration
+  mate-desktop-configuration
+  (mate-package mate-package (default mate)))
+
+(define mate-desktop-service-type
+  (service-type
+   (name 'mate-desktop)
+   (extensions
+    (list (service-extension polkit-service-type
+                             (compose list
+                                      (package-direct-input-selector
+                                       "mate-settings-daemon")
+                                      mate-package))
+          (service-extension profile-service-type
+                             (compose list
+                                      mate-package))))))
+
+(define* (mate-desktop-service #:key (config (mate-desktop-configuration)))
+  "Return a service that adds the @code{mate} package to the system profile,
+and extends polkit with the actions from @code{mate-settings-daemon}."
+  (service mate-desktop-service-type config))
+
 
 ;;;
 ;;; XFCE desktop service.