config/guix/config: Add touchpad configuration

.config/guix/config.scm

@@ -59,13 +59,27 @@
 ;;        (sha256
 ;;         (base32 "127nghkfd4dl5mkf5xl1mij2ylxhkgg08nlh912xwrrjyjv4y9sa"))))))
 
-(define my-xorg-modules
+(define %mimimi/xorg-modules
   ;; Everything but Nouveau.
   (delete xf86-video-nouveau %default-xorg-modules))
 
+(define %mimimi/xorg-touchpad
+  "Section \"InputClass\"
+  Identifier \"Touchpads\"
+  Driver \"libinput\"
+  MatchDevicePath \"/dev/input/event*\"
+  MatchIsTouchpad \"on\"
+
+  Option \"DisableWhileTyping\" \"on\"
+  Option \"MiddleEmulation\" \"on\"
+  Option \"ClickMethod\" \"clickfinger\"
+  Option \"ScrollMethod\" \"twofinger\"
+  Option \"NaturalScrolling\" \"true\"
+EndSection")
+
 ;; Use the "desktop" services, which include the X11
 ;; log-in service, networking with Wicd, and more.
-(define %my-services
+(define %mimimi/services
   (modify-services
       %desktop-services
     (guix-service-type config =>
@@ -90,7 +104,11 @@
                        (slim-configuration
                         (inherit config)
                         (auto-login? #f)
-                        (startx (xorg-start-command #:modules my-xorg-modules))
+                        (startx (xorg-start-command #:modules %mimimi/xorg-modules
+                                                    #:configuration-file
+                                                    (xorg-configuration-file
+                                                     #:extra-config
+                                                     (list %mimimi/xorg-touchpad))))
                         ;; TODO: Can't slim pre-fill the username?
                         (default-user "ambrevar")))))
 
@@ -185,7 +203,7 @@
                       (extensions
                        (list cups-filters escpr hplip))))
             (tor-service)
-            %my-services))
+            %mimimi/services))
 
  ;; Allow resolution of '.local' host names with mDNS.
  (name-service-switch %mdns-host-lookup-nss))