[bug#44354] [PATCH] gnu: gnome-deskop-service-type: Set GUIX_GTK*_IM_MODULE_FILE.

[Leo Prikler]

This makes it, so that GNOME can handle system-wide input methods installed
by adding them to the gnome package, to the operating system packages, or
to some other profile-service.  An example would be a system-wide installation
of ibus along with input methods like ibus-anthy or ibus-rime.

* gnu/services/desktop.scm (gnome-environment): New variable.
(gnome-desktop-service-type)[extensions]: Use it here.
---
 gnu/services/desktop.scm | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/gnu/services/desktop.scm b/gnu/services/desktop.scm
index 265cf9f35f..8a571aacb0 100644
--- a/gnu/services/desktop.scm
+++ b/gnu/services/desktop.scm
@@ -918,12 +918,43 @@ rules."
            "gnome-system-monitor"
            "gvfs"))))
 
+(define (gnome-environment config)
+  (let* ((lib "/run/current-system/profile/lib")
+         (im-module-files
+          `(("3"
+             "GUIX_GTK3_IM_MODULE_FILE"
+             .
+             ,(string-append lib "/gtk-3.0/3.0.0/immodules-gtk3.cache"))
+            ("2"
+             "GUIX_GTK2_IM_MODULE_FILE"
+             .
+             ,(string-append lib "/gtk-2.0/2.10.0/immodules-gtk2.cache"))))
+         (versions
+          (filter-map
+           (match-lambda
+             ((_ pkg)
+              (and (package? pkg)
+                   (string=? (package-name pkg) "gtk+")
+                   (version-major (package-version pkg))))
+             ((_ pkg "out")
+              (and (package? pkg)
+                   (string=? (package-name pkg) "gtk+")
+                   (version-major (package-version pkg))))
+             (_ #f))
+           (package-transitive-inputs (gnome-package config)))))
+    (filter-map
+     (lambda (version)
+       (assoc-ref im-module-files version))
+     (delete-duplicates versions))))
+
 (define gnome-desktop-service-type
   (service-type
    (name 'gnome-desktop)
    (extensions
     (list (service-extension polkit-service-type
                              gnome-polkit-settings)
+          (service-extension session-environment-service-type
+                             gnome-environment)
           (service-extension profile-service-type
                              (compose list
                                       gnome-package))))
-- 
2.29.1