feat: add a basic configuration system

ags/bar/widgets/workspaces.ts

@@ -1,3 +1,4 @@
+import { config } from "lib/settings.js";
 import { BarWidget } from "../bar-widget.js";
 
 const hyprland = await Service.import("hyprland");
@@ -22,9 +23,10 @@ export const Workspaces = (monitor: number) =>
         (workspaces, active) => {
           // Workspaces start with ID 1. It is limited to 25 to keep it reasonable should hyprland
           // return anything unexpected.
-          const workspaces_num = Math.min(
-            25,
-            Math.max(...workspaces.map((workspace) => workspace.id)),
+          const workspaces_num = Math.max(
+            // Always prioritize the value from the config as a minimum amount.
+            config.minWorkspaces,
+            Math.min(25, Math.max(...workspaces.map((workspace) => workspace.id))),
           );
           const children = new Array(workspaces_num);
 

ags/lib/settings.ts

@@ -0,0 +1,46 @@
+import GLib from "gi://GLib";
+
+/** The folder where this program's config files are found. */
+export let config_root = "";
+
+const xdg_config_home = GLib.getenv("XDG_CONFIG_HOME");
+if (xdg_config_home !== null) {
+  config_root = `${xdg_config_home}/mithril-shell`;
+} else {
+  config_root = `${Utils.HOME}/.config/mithril-shell`;
+}
+
+/** The program configuration. */
+export let config = {
+  minWorkspaces: opt<number>(3),
+  lockCommand: opt<string | null>(null),
+};
+
+/**
+ * Reads the program configuration from the config file and updates the configuration.
+ *
+ * For the sake of simplicity this expects all keys to be set in the config file (home-manager will
+ * set missing keys). If no config file is found, the default configuration is used.
+ */
+export function readConfig() {
+  try {
+    const config_str = Utils.readFile(`${config_root}/settings.json`);
+    if (config_str === "") {
+      // Use the default config when no configuration file is found.
+      print("No configuration file found.");
+      return;
+    }
+
+    // The configuration should be type checked in the home-manager module, so it is not too big of
+    // a deal to just do this.
+    config = JSON.parse(config_str);
+  } catch (e) {
+    print(`Failed to read configuration: ${e}`);
+    return;
+  }
+}
+
+/** Helper function to define a config value with a type in a nice manner. */
+function opt<T>(fallback: T): T {
+  return fallback;
+}

ags/main.ts

@@ -2,6 +2,7 @@ import Gdk from "gi://Gdk";
 import type Gtk from "gi://Gtk?version=3.0";
 
 import { Bar } from "./bar/bar.js";
+import { readConfig } from "./lib/settings.js";
 import { Quicksettings } from "./quicksettings/quicksettings.js";
 
 function forMonitors(widget: (monitor: number) => Gtk.Window) {
@@ -10,6 +11,7 @@ function forMonitors(widget: (monitor: number) => Gtk.Window) {
 }
 
 export function main(dest: string): void {
+  readConfig();
   App.config({
     style: `${dest}/style.css`,
     windows: [...forMonitors(Bar), Quicksettings()],

ags/quicksettings/quicksettings.ts

@@ -1,3 +1,4 @@
+import { config } from "lib/settings";
 import type { Icon } from "lib/types";
 import type { Binding } from "types/service";
 import { PopupWindow, showModal } from "window";
@@ -82,11 +83,14 @@ export const Quicksettings = () => {
     Button({
       icon: "system-lock-screen-symbolic",
       onClick() {
-        // TODO: implement this when a configuration system is introduced.
-        Utils.execAsync(
-          `notify-send -a System "Unable to lock" "Locking via the bar is not yet implemented."`,
-        );
         App.closeWindow("quicksettings");
+
+        if (config.lockCommand === null) {
+          Utils.execAsync(`notify-send -a System "Unable to lock" "No lock command configured."`);
+          return;
+        }
+
+        Utils.execAsync(config.lockCommand);
       },
     }),
     Button({

modules/mithril-shell.nix

@@ -64,6 +64,28 @@ in
       surface0 = mkHexColorOption "#313244";
     };
 
+    settings = {
+      minWorkspaces = mkOption {
+        type = types.int;
+        default = 3;
+        example = 10;
+        description = ''
+          The minimum amount of workspaces to show regardless of if they are empty or not.
+        '';
+      };
+
+      lockCommand = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = ''
+          ''${pkgs.hyprlock}/bin/hyprlock --immediate
+        '';
+        description = ''
+          The command used to lock the screen. Set to null to disable.
+        '';
+      };
+    };
+
     integrations = {
       hyprland.enable = mkOption {
         type = types.bool;
@@ -109,6 +131,10 @@ in
       };
     };
 
+    xdg.configFile = {
+      "mithril-shell/settings.json".text = builtins.toJSON cfg.settings;
+    };
+
     services.mithril-shell.finalPackage =
       let
         generateThemeScss = colors: ''