feat: Support for PowerManager.BatteryStatus on WASM

src/SamplesApp/UITests.Shared/Windows_System/Power/PowerManager.xaml.cs

@@ -31,10 +31,23 @@ public PowerManager()
 			UwpPowerManager.EnergySaverStatusChanged += UwpPowerManager_EnergySaverStatusChanged;
 			UwpPowerManager.RemainingChargePercentChanged += UwpPowerManager_RemainingChargePercentChanged;
 			UwpPowerManager.PowerSupplyStatusChanged += UwpPowerManager_PowerSupplyStatusChanged;
-			BatteryStatusOutput.Text = UwpPowerManager.BatteryStatus.ToString();
-			EnergySaverStatusOuptut.Text = UwpPowerManager.EnergySaverStatus.ToString();
-			RemainingChargePercentOutput.Text = UwpPowerManager.RemainingChargePercent.ToString();
-			PowerSupplyStatusOuptut.Text = UwpPowerManager.PowerSupplyStatus.ToString();
+			BatteryStatusOutput.Text = SafeGetter(() => UwpPowerManager.BatteryStatus.ToString());
+			EnergySaverStatusOuptut.Text = SafeGetter(() => UwpPowerManager.EnergySaverStatus.ToString());
+			RemainingChargePercentOutput.Text = SafeGetter(() => UwpPowerManager.RemainingChargePercent.ToString());
+			PowerSupplyStatusOuptut.Text = SafeGetter(() => UwpPowerManager.PowerSupplyStatus.ToString());
+		}
+
+		private string SafeGetter(Func<string> action)
+		{
+			try
+			{
+				return action();
+			}
+			catch (Exception)
+			{
+				// Ignore
+				return "Not implemented";
+			}
 		}
 
 		private async void UwpPowerManager_PowerSupplyStatusChanged(object sender, object e)

src/Uno.UI/ts/Windows/System/Power/PowerManager.ts

@@ -0,0 +1,32 @@
+declare class BatteryManager {
+	charging: boolean;
+}
+
+interface Navigator {
+	getBattery(): Promise<BatteryManager>;
+}
+
+
+namespace Windows.System.Power {
+
+	export class PowerManager {
+
+		private static battery: BatteryManager;
+
+		public static async initializeAsync(): Promise<string> {
+			if (!PowerManager.battery) {
+				PowerManager.battery = await navigator.getBattery();
+			}
+
+			return null;
+		}
+
+		public static getBatteryStatus(): string {
+			if (PowerManager.battery) {
+				return PowerManager.battery.charging ? "Charging" : "Discharging";
+			}
+
+			return "Idle";
+		}
+	}
+}

src/Uno.UWP/System/Power/PowerManager.cs

@@ -1,4 +1,4 @@
-#if __ANDROID__ || __IOS__
+#if __ANDROID__ || __IOS__ || __WASM__
 using System;
 using System.Collections.Generic;
 using System.Text;
@@ -7,6 +7,7 @@ namespace Windows.System.Power
 {
 	public partial class PowerManager
 	{
+#if !__WASM__
 		private static object _syncLock = new object();
 
 		private static PowerSupplyStatus? _lastPowerSupplyStatus;
@@ -18,9 +19,10 @@ public partial class PowerManager
 		private static EventHandler<object> _energySaverStatusChanged;
 		private static EventHandler<object> _remainingChargePercentChanged;
 		private static EventHandler<object> _batteryStatusChanged;
-
+#endif
 		public static BatteryStatus BatteryStatus => GetBatteryStatus();
 
+#if !__WASM__
 		public static EnergySaverStatus EnergySaverStatus => GetEnergySaverStatus();
 
 		public static PowerSupplyStatus PowerSupplyStatus => GetPowerSupplyStatus();
@@ -173,6 +175,7 @@ internal static void RaiseEnergySaverStatusChanged()
 				_energySaverStatusChanged?.Invoke(null, null);
 			}
 		}
+#endif
 	}
 }
 #endif

src/Uno.UWP/System/Power/PowerManager.wasm.cs

@@ -0,0 +1,22 @@
+#nullable enable
+
+using System;
+using Uno.Foundation;
+
+namespace Windows.System.Power;
+
+public partial class PowerManager
+{
+	private const string JsType = "Windows.System.Power.PowerManager";
+
+	private static BatteryStatus GetBatteryStatus()
+	{
+		WebAssemblyRuntime.InvokeAsync($"{JsType}.initializeAsync()");
+		var batteryStatusString = WebAssemblyRuntime.InvokeJS($"{JsType}.getBatteryStatus()");
+		if (Enum.TryParse<BatteryStatus>(batteryStatusString, out var batteryStatus))
+		{
+			return batteryStatus;
+		}
+		return BatteryStatus.NotPresent;
+	}
+}