[Astal] Add battery low notification

config/astal/components/bar/modules/QuickView.tsx

@@ -1,4 +1,5 @@
 import { bind } from "astal";
+import { execAsync } from "astal";
 import AstalBattery from "gi://AstalBattery";
 import AstalBluetooth from "gi://AstalBluetooth";
 import AstalNetwork from "gi://AstalNetwork";
@@ -120,6 +121,8 @@ const BluetoothWidget = () => {
     );
 };
 
+
+let hasSentNotification = false;
 const BatteryWidget = () => {
     const battery = AstalBattery.get_default();
     if (battery.get_is_present()) {
@@ -127,7 +130,14 @@ const BatteryWidget = () => {
             <image
                 iconName={bind(battery, "batteryIconName").as(icon => icon)}
                 cssClasses={["quick-view-symbol"]}
-                tooltipText={bind(battery, 'percentage').as(p => `Battery Level: ${Math.round(p * 100)}%`)}
+                tooltipText={bind(battery, 'percentage').as(p => {
+                    const level = Math.round(p * 100)
+                    if ( level < 20 && !hasSentNotification ) {
+                        hasSentNotification = true;
+                        execAsync( 'bash -c "notify-send \'Battery level below 20%\'"' );
+                    }
+                    return `Battery Level: ${level}%`
+                })}
             ></image>
         );
     } else {