xidlehook: add module (#1761)

Co-authored-by: Nicolas Berbiche <nic.berbiche@gmail.com>

.github/CODEOWNERS

@@ -300,6 +300,8 @@
 
 /modules/services/xembed-sni-proxy.nix                @rycee
 
+/modules/services/xidlehook.nix                       @dschrempf
+
 /modules/services/xscreensaver.nix                    @rycee
 
 /modules/services/xsuspender.nix                      @offlinehacker

modules/misc/news.nix

@@ -2061,6 +2061,14 @@ in
           A new module is available: 'programs.piston-cli'.
         '';
       }
+
+      {
+        time = "2021-06-02T04:24:10+00:00";
+        condition = hostPlatform.isLinux;
+        message = ''
+          A new module is available: 'services.xidlehook'.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -219,6 +219,7 @@ let
     (loadModule ./services/wlsunset.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xcape.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xembed-sni-proxy.nix { condition = hostPlatform.isLinux; })
+    (loadModule ./services/xidlehook.nix { condition = hostPlatform.isLinux; })
     (loadModule ./services/xscreensaver.nix { })
     (loadModule ./services/xsuspender.nix { condition = hostPlatform.isLinux; })
     (loadModule ./systemd.nix { })

modules/services/xidlehook.nix

@@ -0,0 +1,149 @@
+# Wrapper around xidlehook.
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.xidlehook;
+
+  notEmpty = list: filter (x: x != "" && x != null) (flatten list);
+
+  timers = let
+    toTimer = timer:
+      "--timer ${toString timer.delay} ${
+        escapeShellArgs [ timer.command timer.canceller ]
+      }";
+  in map toTimer (filter (timer: timer.command != null) cfg.timers);
+
+  script = pkgs.writeShellScript "xidlehook" ''
+    ${concatStringsSep "\n"
+    (mapAttrsToList (name: value: "export ${name}=${value}")
+      cfg.environment or { })}
+    ${concatStringsSep " " (notEmpty [
+      "${cfg.package}/bin/xidlehook"
+      (optionalString cfg.once "--once")
+      (optionalString cfg.not-when-fullscreen "--not-when-fullscreen")
+      (optionalString cfg.not-when-audio "--not-when-audio")
+      timers
+    ])}
+  '';
+in {
+  meta.maintainers = [ maintainers.dschrempf ];
+
+  options.services.xidlehook = {
+    enable = mkEnableOption "xidlehook systemd service";
+
+    package = mkOption {
+      type = types.package;
+      default = pkgs.xidlehook;
+      defaultText = "pkgs.xidlehook";
+      description = "The package to use for xidlehook.";
+    };
+
+    environment = mkOption {
+      type = types.attrsOf types.str;
+      default = { };
+      example = literalExample ''
+        {
+          "primary-display" = "$(xrandr | awk '/ primary/{print $1}')";
+        }
+      '';
+      description = ''
+        Extra environment variables to be exported in the script.
+        These options are passed unescaped as <code>export name=value</code>.
+      '';
+    };
+
+    not-when-fullscreen = mkOption {
+      type = types.bool;
+      default = false;
+      example = true;
+      description = "Disable locking when a fullscreen application is in use.";
+    };
+
+    not-when-audio = mkOption {
+      type = types.bool;
+      default = false;
+      example = true;
+      description = "Disable locking when audio is playing.";
+    };
+
+    once = mkEnableOption "running the program once and exiting";
+
+    timers = mkOption {
+      type = types.listOf (types.submodule {
+        options = {
+          delay = mkOption {
+            type = types.ints.unsigned;
+            example = 60;
+            description = "Time before executing the command.";
+          };
+          command = mkOption {
+            type = types.nullOr types.str;
+            example = literalExample ''
+              ''${pkgs.libnotify}/bin/notify-send "Idle" "Sleeping in 1 minute"
+            '';
+            description = ''
+              Command executed after the idle timeout is reached.
+              Path to executables are accepted.
+              The command is automatically escaped.
+            '';
+          };
+          canceller = mkOption {
+            type = types.str;
+            default = "";
+            example = literalExample ''
+              ''${pkgs.libnotify}/bin/notify-send "Idle" "Resuming activity"
+            '';
+            description = ''
+              Command executed when the user becomes active again.
+              This is only executed if the next timer has not been reached.
+              Path to executables are accepted.
+              The command is automatically escaped.
+            '';
+          };
+        };
+      });
+      default = [ ];
+      example = literalExample ''
+        [
+          {
+            delay = 60;
+            command = "xrandr --output \"$PRIMARY_DISPLAY\" --brightness .1";
+            canceller = "xrandr --output \"$PRIMARY_DISPLAY\" --brightness 1";
+          }
+          {
+            delay = 120;
+            command = "''${pkgs.writeShellScript "my-script" '''
+              # A complex script to run
+            '''}";
+          }
+        ]
+      '';
+      description = ''
+        A set of commands to be executed after a specific idle timeout.
+        The commands specified in <literal>command</literal> and <literal>canceller</literal>
+        are passed escaped to the script.
+        To use or re-use environment variables that are script-dependent, specify them
+        in the <literal>environment</literal> section.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.user.services.xidlehook = {
+      Unit = {
+        Description = "xidlehook service";
+        PartOf = [ "graphical-session.target" ];
+        After = [ "graphical-session.target" ];
+        ConditionEnvironment = [ "DISPLAY" ];
+      };
+      Service = {
+        Type = if cfg.once then "oneshot" else "simple";
+        ExecStart = "${script}";
+      };
+      Install.WantedBy = [ "graphical-session.target" ];
+    };
+  };
+}