ags: implement per-monitor brightness control

.config/ags/services/brightness.js

@@ -1,10 +1,11 @@
+import Hyprland from 'resource:///com/github/Aylur/ags/service/hyprland.js';
 import Service from 'resource:///com/github/Aylur/ags/service.js';
 import * as Utils from 'resource:///com/github/Aylur/ags/utils.js';
 const { exec, execAsync } = Utils;
 
 import { clamp } from '../modules/.miscutils/mathfuncs.js';
 
-class BrightnessService extends Service {
+class BrightnessServiceBase extends Service {
     static {
         Service.register(
             this,
@@ -23,7 +24,7 @@ class BrightnessService extends Service {
         percent = clamp(percent, 0, 1);
         this._screenValue = percent;
 
-        Utils.execAsync(`brightnessctl s ${percent * 100}% -q`)
+        Utils.execAsync(this.setBrightnessCmd(percent))
             .then(() => {
                 // signals has to be explicity emitted
                 this.emit('screen-changed', percent);
@@ -35,13 +36,6 @@ class BrightnessService extends Service {
             .catch(print);
     }
 
-    constructor() {
-        super();
-        const current = Number(exec('brightnessctl g'));
-        const max = Number(exec('brightnessctl m'));
-        this._screenValue = current / max;
-    }
-
     // overwriting connectWidget method, lets you
     // change the default event that widgets connect to
     connectWidget(widget, callback, event = 'screen-changed') {
@@ -49,11 +43,70 @@ class BrightnessService extends Service {
     }
 }
 
+class BrightnessCtlService extends BrightnessServiceBase {
+    static {
+        Service.register(this);
+    }
+
+    constructor() {
+        super();
+        const current = Number(exec('brightnessctl g'));
+        const max = Number(exec('brightnessctl m'));
+        this._screenValue = current / max;
+    }
+
+    setBrightnessCmd(percent) {
+        return `brightnessctl s ${percent * 100}% -q`;
+    }
+}
+
+class BrightnessDdcService extends BrightnessServiceBase {
+    static {
+        Service.register(this);
+    }
+
+    constructor(monitor = 0) {
+        super();
+        // don't use Hyprland.getMonitor(id), Hyprland monitor id isn't consistent
+        // with Gdk, but the Array ordering is (magically)
+        this._sn = Hyprland.monitors[monitor].serial;
+        Utils.execAsync(`ddcutil --sn ${this._sn} getvcp 10 --brief`)
+            .then((out) => {
+                // only the last line is useful
+                out = out.split('\n');
+                out = out[out.length - 1];
+
+                out = out.split(' ');
+                const current = Number(out[3]);
+                const max = Number(out[4]);
+                this._screenValue = current / max;
+            })
+            .catch(print);
+    }
+
+    setBrightnessCmd(percent) {
+        return `ddcutil --sn ${this._sn} setvcp 10 ${Math.round(percent * 100)}`;
+    }
+}
+
 // the singleton instance
-const service = new BrightnessService();
+const numMonitors = Hyprland.monitors.length;
+const service = Array(numMonitors);
+switch (userOptions.brightness.controller) {
+    case "brightnessctl":
+        service.fill(new BrightnessCtlService());
+        break;
+    case "ddcutil":
+        for (let i = 0; i < numMonitors; i++) {
+            service[i] = new BrightnessDdcService(i);
+        }
+        break;
+    default:
+        throw new Error(`Unknown brightness controller ${userOptions.brightness.controller}`);
+}
 
 // make it global for easy use with cli
-globalThis.brightness = service;
+globalThis.brightness = service[0];
 
 // export to use in other modules
-export default service;
+export default service;