[bug#75270] [PATCH v3 3/3] services: greetd: Add new gtkgreet greeter.

[muradm <mail@muradm.net>]

* gnu/services/base.scm (<greetd-gtkgreet-sway-session>): New record,
represents `gtkgreet` greeter session configuration.
* doc/guix.texi (Base Services): Document new `gtkgreet` greeter.

Change-Id: Idb226862bb0fc57404ebb8bd46e2192d7d4e57c6
---
 doc/guix.texi         | 48 +++++++++++++++++++++++++++++++++++++++++--
 gnu/services/base.scm | 33 +++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index ba7b1761c3..28f94901ab 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -20592,8 +20592,9 @@ Base Services
 The user to use for running the greeter.
 
 @item @code{default-session-command} (default: @code{(greetd-agreety-session)})
-Can be either @code{greetd-agreety-session}, @code{greetd-wlgreet-sway-session} or
-@code{gexp->script} like object to use as greeter.
+Can be either @code{greetd-agreety-session}, @code{greetd-wlgreet-sway-session},
+@code{greetd-gtkgreet-sway-session} or @code{gexp->script} like object to use
+as greeter.
 
 @end table
 @end deftp
@@ -20730,6 +20731,49 @@ Base Services
 @end lisp
 @end deftp
 
+@deftp {Data Type} greetd-gtkgreet-sway-session
+Configuration record for the gtkgreet greetd greeter.  Can be used as
+following:
+
+@lisp
+  (greetd-configuration
+   ;; Graphical greeter require additional group membership.
+   (greeter-supplementary-groups (list "video" "input" "seat"))
+   (terminals
+    (list (greetd-terminal-configuration
+           (terminal-vt "1")
+           (terminal-switch #t)
+           (default-session-command
+            (greetd-gtkgreet-sway-session
+             ;; optionally use Adwaita:dark configured version
+             (gtkgreet gtkgreet-adwaita-dark)
+             (command
+              (greetd-user-session
+               ;; signal to our .bashrc that we want wayland compositor
+               (xdg-session-type "wayland")))))))))
+@end lisp
+
+@table @asis
+@item @code{sway} (default: @code{sway})
+The package with @command{/bin/sway} and @command{/bin/swaymsg} commands.
+
+@item @code{sway-config} (default: @code{(plain-file "greetd-gtkgreet-sway-config" "")})
+Extra configuration for sway to be included before executing greeter.
+
+@item @code{gtkgreet} (default: @code{gtkgreet})
+The package with @command{/bin/gtkgreet} command.
+
+@item @code{gtkgreet-style} (default: @code{(plain-file "greetd-gtkgreet-sway-gtkgreet-style.css" "")})
+Extra CSS stylesheet to customize GTK look.
+
+@item @code{command} (default: @code{(greetd-user-session)})
+Command to be started by @command{/bin/agreety} on successful login.
+Normally should be a variation of @code{greetd-user-session}, but could
+be any @code{gexp->script} like object.
+
+@end table
+@end deftp
+
 @node Scheduled Job Execution
 @subsection Scheduled Job Execution
 
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index b6d5e104a2..58f233770e 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -279,6 +279,7 @@ (define-module (gnu services base)
             greetd-wlgreet-color
             greetd-wlgreet-configuration
             greetd-wlgreet-sway-session
+            greetd-gtkgreet-sway-session
 
             %base-services))
 
@@ -3560,6 +3561,38 @@ (define-gexp-compiler (greetd-wlgreet-sway-session-compiler
       sway
       (make-greetd-wlgreet-sway-session-sway-config session)))))
 
+(define-record-type* <greetd-gtkgreet-sway-session>
+  greetd-gtkgreet-sway-session make-greetd-gtkgreet-sway-session
+  greetd-gtkgreet-sway-session?
+  (sway greetd-gtkgreet-sway-session-sway (default sway))
+  (sway-config greetd-wlgreet-sway-session-sway-config
+               (default (plain-file "greetd-gtkgreet-sway-config" "")))
+  (gtkgreet greetd-gtkgreet-sway-session-gtkgreet (default gtkgreet))
+  (gtkgreet-style greetd-gtkgreet-sway-session-gtkgreet-style
+                  (default (plain-file "greetd-gtkgreet-sway-gtkgreet-style.css" "")))
+  (command greetd-gtkgreet-sway-session-command (default (greetd-user-session))))
+
+(define make-greetd-gtkgreet-sway-session-sway-config
+  (match-lambda
+    (($ <greetd-gtkgreet-sway-session> sway sway-config gtkgreet gtkgreet-style command)
+     (let ((gtkgreet-bin (file-append gtkgreet "/bin/gtkgreet"))
+           (swaymsg-bin (file-append sway "/bin/swaymsg")))
+       (mixed-text-file
+        "gtkgreet-sway-config"
+        "include " sway-config "\n"
+        "xwayland disable\n"
+        "exec \"" gtkgreet-bin " -l -s " gtkgreet-style " -c " command "; " swaymsg-bin " exit\"\n")))))
+
+(define-gexp-compiler (greetd-gtkgreet-sway-session-compiler
+                       (session <greetd-gtkgreet-sway-session>)
+                       system target)
+  (match-record session <greetd-gtkgreet-sway-session>
+    (sway)
+    (lower-object
+     (make-greetd-sway-greeter-command
+      sway
+      (make-greetd-gtkgreet-sway-session-sway-config session)))))
+
 (define-record-type* <greetd-terminal-configuration>
   greetd-terminal-configuration make-greetd-terminal-configuration
   greetd-terminal-configuration?
-- 
2.47.1