swayosd: add module

modules/misc/news.nix

@@ -1157,6 +1157,14 @@ in
           A new module is available: 'programs.pyenv'.
         '';
       }
+
+      {
+        time = "2023-07-08T09:44:56+00:00";
+        condition = hostPlatform.isLinux;
+        message = ''
+          A new module is available: 'services.swayosd'
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -312,6 +312,7 @@ let
     ./services/stalonetray.nix
     ./services/status-notifier-watcher.nix
     ./services/swayidle.nix
+    ./services/swayosd.nix
     ./services/sxhkd.nix
     ./services/syncthing.nix
     ./services/systembus-notify.nix

modules/services/swayosd.nix

@@ -0,0 +1,58 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  cfg = config.services.swayosd;
+
+in {
+  meta.maintainers = [ hm.maintainers.pltanton ];
+
+  options.services.swayosd = {
+    enable = mkEnableOption ''
+      swayosd, a GTK based on screen display for keyboard shortcuts like
+      caps-lock and volume'';
+
+    package = mkPackageOption pkgs "swayosd" { };
+
+    maxVolume = mkOption {
+      type = types.nullOr types.ints.unsigned;
+      default = null;
+      example = 120;
+      description = ''
+        Sets the maximum volume.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    assertions = [
+      (hm.assertions.assertPlatform "services.swayosd" pkgs platforms.linux)
+    ];
+
+    home.packages = [ cfg.package ];
+
+    systemd.user = {
+      services.swayosd = {
+        Unit = {
+          Description = "Volume/backlight OSD indicator";
+          PartOf = [ "graphical-session.target" ];
+          After = [ "graphical-session.target" ];
+          ConditionEnvironment = "WAYLAND_DISPLAY";
+          Documentation = "man:swayosd(1)";
+        };
+
+        Service = {
+          Type = "simple";
+          ExecStart = "${cfg.package}/bin/swayosd"
+            + (optionalString (cfg.maxVolume != null)
+              " --max-volume ${toString cfg.maxVolume}");
+          Restart = "always";
+        };
+
+        Install = { WantedBy = [ "graphical-session.target" ]; };
+      };
+    };
+  };
+}

tests/default.nix

@@ -222,6 +222,7 @@ import nmt {
     ./modules/services/redshift-gammastep
     ./modules/services/screen-locker
     ./modules/services/swayidle
+    ./modules/services/swayosd
     ./modules/services/sxhkd
     ./modules/services/syncthing/linux
     ./modules/services/trayer

tests/modules/services/swayosd/default.nix

@@ -0,0 +1 @@
+{ swayosd = ./swayosd.nix; }

tests/modules/services/swayosd/swayosd.nix

@@ -0,0 +1,35 @@
+{ config, ... }:
+
+{
+  services.swayosd = {
+    enable = true;
+    package = config.lib.test.mkStubPackage {
+      name = "swayosd";
+      outPath = "@swayosd@";
+    };
+    maxVolume = 10;
+  };
+
+  nmt.script = ''
+    assertFileContent \
+      home-files/.config/systemd/user/swayosd.service \
+      ${
+        builtins.toFile "swayosd.service" ''
+          [Install]
+          WantedBy=graphical-session.target
+
+          [Service]
+          ExecStart=@swayosd@/bin/swayosd --max-volume 10
+          Restart=always
+          Type=simple
+
+          [Unit]
+          After=graphical-session.target
+          ConditionEnvironment=WAYLAND_DISPLAY
+          Description=Volume/backlight OSD indicator
+          Documentation=man:swayosd(1)
+          PartOf=graphical-session.target
+        ''
+      }
+  '';
+}