nixos/plotinus: add module to enable plotinus

nixos/modules/programs/plotinus.nix

@@ -0,0 +1,36 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.programs.plotinus;
+in
+{
+  meta = {
+    maintainers = pkgs.plotinus.meta.maintainers;
+    doc = ./plotinus.xml;
+  };
+
+  ###### interface
+
+  options = {
+    programs.plotinus = {
+      enable = mkOption {
+        default = false;
+        description = ''
+          Whether to enable the Plotinus GTK+3 plugin.  Plotinus provides a
+          popup (triggered by Ctrl-Shift-P) to search the menus of a
+          compatible application.
+        '';
+        type = types.bool;
+      };
+    };
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+    environment.variables.XDG_DATA_DIRS = [ "${pkgs.plotinus}/share/gsettings-schemas/${pkgs.plotinus.name}" ];
+    environment.variables.GTK3_MODULES = [ "${pkgs.plotinus}/lib/libplotinus.so" ];
+  };
+}

nixos/modules/programs/plotinus.xml

@@ -0,0 +1,25 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         version="5.0"
+         xml:id="module-program-plotinus">
+
+<title>Plotinus</title>
+
+<para><emphasis>Source:</emphasis> <filename>modules/programs/plotinus.nix</filename></para>
+
+<para><emphasis>Upstream documentation:</emphasis> <link xlink:href="https://github.com/p-e-w/plotinus"/></para>
+
+<para>Plotinus is a searchable command palette in every modern GTK+ application.</para>
+
+<para>When in a GTK+3 application and Plotinus is enabled, you can press <literal>Ctrl+Shift+P</literal> to open the command palette.  The command palette provides a searchable list of of all menu items in the application.</para>
+
+<para>To enable Plotinus, add the following to your <filename>configuration.nix</filename>:
+
+<programlisting>
+programs.plotinus.enable = true;
+</programlisting>
+
+</para>
+
+</chapter>