Factor out common desktop services

Most of the code for setting desktop layouts is common between machines.

Also, make the blueman-applet service reusable.

1 files changed, 130 insertions, 0 deletions

diff --git a/tw/services/desktop.scm b/tw/services/desktop.scm
new file mode 100644
index 00000000..b0bb4e8a
--- /dev/null
+++ b/tw/services/desktop.scm
@@ -0,0 +1,130 @@
+(define-module (tw services desktop)
+  #:use-module (gnu)
+  #:use-module (gnu home services)
+  #:use-module (gnu home services shepherd)
+  #:use-module ((gnu packages networking) #:select (blueman))
+  #:use-module ((gnu packages wm) #:select (polybar))
+  #:use-module ((gnu packages xdisorg) #:select (numlockx hsetroot))
+  #:use-module ((gnu packages xorg) #:select (xrandr xset))
+  #:use-module (gnu services configuration)
+  #:use-module (guix gexp)
+  #:use-module (guix packages)
+  #:use-module ((guix records) #:select (match-record))
+  #:use-module (srfi srfi-1)
+  #:use-module ((tw theme) #:select (catppuccin-polybar))
+  #:export (home-desktop-layout-configuration
+            home-monitor-configuration
+            home-desktop-layout-service-type
+            home-blueman-service-type))
+
+
+;; Monitor layout and polybars
+
+(define (list-of-strings? thing)
+  (and (list? thing) (every string? thing)))
+
+(define-configuration/no-serialization home-monitor-configuration
+  (name string "The monitor's name in X11.")
+  (xrandr-options (list-of-strings '()) "Options to pass to xrandr to
+configure this monitor."))
+
+(define (list-of-monitors? thing)
+  (and (list? thing) (every home-monitor-configuration? thing)))
+
+(define-configuration/no-serialization home-desktop-layout-configuration
+  (desktop-background string "Path to an image that will be set as the desktop
+background.  An initial @code{~/} is replaced with $HOME/.")
+  (monitors list-of-monitors "List of monitor declarations to apply."))
+
+(define (polybar-config monitors)
+  `(("polybar/config.ini" ,(local-file "files/polybar.ini"))
+    ("polybar/catppuccin.ini" ,catppuccin-polybar)))
+
+(define polybar-wrapper
+  (program-file "polybar-wrapper"
+    #~(begin
+        ;; This wrapper program checks that the monitor we want to start
+        ;; polybar on is actually connected.
+        (use-modules (ice-9 popen)
+                     (ice-9 rdelim))
+        (let* ((connected-str (string-append (getenv "POLYBAR_MONITOR") " connected"))
+               (xrandr (open-pipe* OPEN_READ #$(file-append xrandr "/bin/xrandr") "-q"))
+               (monitor-connected?
+                (let loop ((line (read-line xrandr)))
+                  (cond
+                   ((eof-object? line) #f)                   ; we didn't find our monitor connected
+                   ((string-prefix? connected-str line) #t)  ; the monitor we want is connected
+                   (else (loop (read-line xrandr)))))))      ; keep looking
+          (close-pipe xrandr)
+          (when monitor-connected?
+            (execl #$(file-append polybar "/bin/polybar")))))))
+
+(define (polybar-service monitor)
+  (shepherd-service
+   (documentation (string-append "Polybar desktop bar for monitor " monitor "."))
+   (provision (list (symbol-append 'polybar- (string->symbol monitor))))
+   (requirement '(xorg-setup))
+   (start #~(make-forkexec-constructor
+             (list #$polybar-wrapper)
+             #:environment-variables
+             (cons #$(string-append "POLYBAR_MONITOR=" monitor)
+                   (default-environment-variables))))
+   (stop #~(make-kill-destructor))))
+
+(define (desktop-layout-services config)
+  (match-record config <home-desktop-layout-configuration>
+    (desktop-background monitors)
+    (cons* (shepherd-service
+            (documentation "Set up X displays on login.")
+            (provision '(xorg-setup))
+            (one-shot? #t)
+            (start #~(lambda _
+                       (define (replace-home path)
+                         (if (string-prefix? "~/" path)
+                             (string-replace path (getenv "HOME") 0 1)
+                             path))
+                       (system* #$(file-append numlockx "/bin/numlockx") "on")
+                       ;; Turn off the monitors if there is no input for 10 minutes.
+                       (system* #$(file-append xset "/bin/xset") "dpms" "600" "600" "600")
+                       ;; TODO: may need one xrandr invocation per monitor; this is
+                                        ; ;what tw/home/cern.scm had before.
+                       (system* #$(file-append xrandr "/bin/xrandr")
+                                #$@(append-map (lambda (monitor)
+                                                 (match-record monitor <home-monitor-configuration>
+                                                   (name xrandr-options)
+                                                   `("--output" ,name ,@xrandr-options)))
+                                               monitors))
+                       ;; Set the desktop background picture. Hopefully doing this just after
+                       ;; xrandr works and sets it for both screens.
+                       (system* #$(file-append hsetroot "/bin/hsetroot")
+                                "-cover" (replace-home #$desktop-background)))))
+           (map (compose polybar-service home-monitor-configuration-name) monitors))))
+
+(define home-desktop-layout-service-type
+  (service-type
+   (name 'desktop-layout)
+   (extensions
+    (list (service-extension home-shepherd-service-type desktop-layout-services)
+          (service-extension home-xdg-configuration-files-service-type polybar-config)))
+   (description
+    "Configure the desktop background, monitor layout and polybar.")))
+
+
+;; Blueman
+
+(define (blueman-services config)
+  (list (shepherd-service
+         (documentation "Blueman applet; provides a GUI for connection to bluetooth devices.")
+         (provision '(blueman-applet))
+         (start #~(make-forkexec-constructor
+                   (list #$(file-append blueman "/bin/blueman-applet"))))
+         (stop #~(make-kill-destructor)))))
+
+(define home-blueman-service-type
+  (service-type
+   (name 'blueman)
+   (default-value #f)
+   (extensions
+    (list (service-extension home-shepherd-service-type blueman-services)))
+   (description
+    "Run the Blueman applet for graphical Bluetooth control.")))