feat: Support for PowerManager on WASM

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

@@ -9,7 +9,7 @@
 	d:DesignHeight="2000"
 	d:DesignWidth="400">
 
-	<Grid RowSpacing="8" Padding="20">
+	<Grid RowSpacing="4" Padding="12">
 		<Grid.RowDefinitions>
 			<RowDefinition Height="Auto" />
 			<RowDefinition Height="*" />

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

@@ -112,6 +112,7 @@ public bool IsBatteryStatusChangedSubscribed
 		{
 			if (value)
 			{
+				UwpPowerManager.BatteryStatusChanged += UwpPowerManager_BatteryStatusChanged;
 				_batteryStatusChangedSubscription.Disposable = Disposable.Create(() =>
 					UwpPowerManager.BatteryStatusChanged -= UwpPowerManager_BatteryStatusChanged);
 			}
@@ -131,6 +132,7 @@ public bool IsEnergySaverStatusChangedSubscribed
 		{
 			if (value)
 			{
+				UwpPowerManager.EnergySaverStatusChanged += UwpPowerManager_EnergySaverStatusChanged;
 				_energySaverStatusChangedSubscription.Disposable = Disposable.Create(() =>
 					UwpPowerManager.EnergySaverStatusChanged -= UwpPowerManager_EnergySaverStatusChanged);
 			}
@@ -150,6 +152,7 @@ public bool IsPowerSupplyStatusChangedSubscribed
 		{
 			if (value)
 			{
+				UwpPowerManager.PowerSupplyStatusChanged += UwpPowerManager_PowerSupplyStatusChanged;
 				_powerSupplyStatusChangedSubscription.Disposable = Disposable.Create(() =>
 					UwpPowerManager.PowerSupplyStatusChanged -= UwpPowerManager_PowerSupplyStatusChanged);
 			}
@@ -169,6 +172,7 @@ public bool IsRemainingChargePercentChangedSubscribed
 		{
 			if (value)
 			{
+				UwpPowerManager.RemainingChargePercentChanged += UwpPowerManager_RemainingChargePercentChanged;
 				_remainingChargePercentChangedSubscription.Disposable = Disposable.Create(() =>
 					UwpPowerManager.RemainingChargePercentChanged -= UwpPowerManager_RemainingChargePercentChanged);
 			}
@@ -188,6 +192,7 @@ public bool IsRemainingDischargeTimeChangedSubscribed
 		{
 			if (value)
 			{
+				UwpPowerManager.RemainingDischargeTimeChanged += UwpPowerManager_RemainingDischargeTimeChanged;
 				_remainingDischargeTimeChangedSubscription.Disposable = Disposable.Create(() =>
 					UwpPowerManager.RemainingDischargeTimeChanged -= UwpPowerManager_RemainingDischargeTimeChanged);
 			}

src/Uno.UI/LinkerDefinition.Wasm.xml

@@ -51,6 +51,11 @@
 		<type fullname="Windows.Devices.Sensors.LightSensor" required="false">
 			<method name="DispatchReading" />
 		</type>
+		<type fullname="Windows.System.Power.PowerManager">
+	  		<method name="DispatchRemainingDischargeTimeChanged" />
+	  		<method name="DispatchRemainingChargePercentChanged" />
+	  		<method name="DispatchChargingChanged" />
+		</type>
 		<type fullname="Windows.Networking.Connectivity.NetworkInformation" required="false">
 			<method name="DispatchStatusChanged" />
 		</type>

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

@@ -1,5 +1,12 @@
 declare class BatteryManager {
 	charging: boolean;
+	level: number;
+	dischargingTime: number;
+
+	addEventListener(
+		type: "chargingchange" | "dischargingtimechange" | "levelchange",
+		listener: (this: this, ev: Event) => any,
+		useCapture?: boolean): void;
 }
 
 interface Navigator {
@@ -12,10 +19,18 @@ namespace Windows.System.Power {
 	export class PowerManager {
 
 		private static battery: BatteryManager;
+		private static dispatchChargingChanged: () => number;
+		private static dispatchRemainingChargePercentChanged: () => number;
+		private static dispatchRemainingDischargeTimeChanged: () => number;
 
 		public static async initializeAsync(): Promise<string> {
 			if (!PowerManager.battery) {
 				PowerManager.battery = await navigator.getBattery();
+
+				// TODO: Subscribe only when requested
+				PowerManager.battery.addEventListener("chargingchange", PowerManager.onChargingChange);
+				PowerManager.battery.addEventListener("dischargingtimechange", PowerManager.onDischargingTimeChange);
+				PowerManager.battery.addEventListener("levelchange", PowerManager.onLevelChange);
 			}
 
 			return null;
@@ -28,5 +43,59 @@ namespace Windows.System.Power {
 
 			return "Idle";
 		}
+
+		public static getPowerSupplyStatus(): string {
+			if (PowerManager.battery) {
+				return PowerManager.battery.charging ? "Adequate" : "NotPresent";
+			}
+
+			return "NotPresent";
+		}
+
+		public static getRemainingChargePercent(): number {
+			if (PowerManager.battery) {
+				return PowerManager.battery.level;
+			}
+
+			return 1.0;
+		}
+
+		public static getRemainingDischargeTime(): number {
+			if (PowerManager.battery) {
+				const dischargingTime = PowerManager.battery.dischargingTime;
+				if (Number.isFinite(dischargingTime)) {
+					return dischargingTime;
+				}
+			}
+
+			return -1;
+		}
+
+		private static onChargingChange() {
+			if (!PowerManager.dispatchChargingChanged) {
+				PowerManager.dispatchChargingChanged =
+					(<any>Module).mono_bind_static_method(
+						"[Uno] Windows.System.Power.PowerManager:DispatchChargingChanged");
+			}
+			PowerManager.dispatchChargingChanged();
+		}
+
+		private static onDischargingTimeChange() {
+			if (!PowerManager.dispatchRemainingDischargeTimeChanged) {
+				PowerManager.dispatchRemainingDischargeTimeChanged =
+					(<any>Module).mono_bind_static_method(
+						"[Uno] Windows.System.Power.PowerManager:DispatchRemainingDischargeTimeChanged");
+			}
+			PowerManager.dispatchRemainingDischargeTimeChanged();
+		}
+
+		private static onLevelChange() {
+			if (!PowerManager.dispatchRemainingChargePercentChanged) {
+				PowerManager.dispatchRemainingChargePercentChanged =
+					(<any>Module).mono_bind_static_method(
+						"[Uno] Windows.System.Power.PowerManager:DispatchRemainingChargePercentChanged");
+			}
+			PowerManager.dispatchRemainingChargePercentChanged();
+		}
 	}
 }

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

@@ -19,7 +19,7 @@ public partial class PowerManager
 		private static readonly UIDevice _device;
 		private static readonly bool _isSimulator;
 
-		static PowerManager()
+		static partial void InitializePlatform()
 		{
 			_device = UIDevice.CurrentDevice;
 			_isSimulator = _device.Model?

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

@@ -1,22 +1,98 @@
 #nullable enable
 
 using System;
+using System.Threading.Tasks;
+using Uno;
 using Uno.Foundation;
+using Uno.Foundation.Logging;
 
 namespace Windows.System.Power;
 
 public partial class PowerManager
 {
 	private const string JsType = "Windows.System.Power.PowerManager";
 
+	[Preserve]
+	public static int DispatchChargingChanged()
+	{
+		RaiseBatteryStatusChanged();
+		RaisePowerSupplyStatusChanged();
+		return 0;
+	}
+
+	[Preserve]
+	public static int DispatchRemainingChargePercentChanged()
+	{
+		RaiseRemainingChargePercentChanged();
+		return 0;
+	}
+
+	[Preserve]
+	public static int DispatchRemainingDischargeTimeChanged()
+	{
+		RaiseRemainingDischargeTimeChanged();
+		return 0;
+	}
+
 	private static BatteryStatus GetBatteryStatus()
 	{
-		WebAssemblyRuntime.InvokeAsync($"{JsType}.initializeAsync()");
+		InitializeAsync(); // TODO
+
 		var batteryStatusString = WebAssemblyRuntime.InvokeJS($"{JsType}.getBatteryStatus()");
-		if (Enum.TryParse<BatteryStatus>(batteryStatusString, out var batteryStatus))
+		return Enum.TryParse<BatteryStatus>(batteryStatusString, out var batteryStatus) ?
+			batteryStatus : BatteryStatus.NotPresent;
+	}
+
+	private static PowerSupplyStatus GetPowerSupplyStatus()
+	{
+		InitializeAsync(); // TODO
+
+		var powerSupplyStatusString = WebAssemblyRuntime.InvokeJS($"{JsType}.getPowerSupplyStatus()");
+		return Enum.TryParse<PowerSupplyStatus>(powerSupplyStatusString, out var powerSupplyStatus) ?
+			powerSupplyStatus : PowerSupplyStatus.NotPresent;
+	}
+
+	private static int GetRemainingChargePercent()
+	{
+		InitializeAsync(); // TODO
+
+		var remainingChargeString = WebAssemblyRuntime.InvokeJS($"{JsType}.getRemainingChargePercent()");
+		if (double.TryParse(remainingChargeString, out var remainingCharge) &&
+			!double.IsNaN(remainingCharge))
+		{
+			return (int)(remainingCharge * 100);
+		}
+
+		return 100;
+	}
+
+	private static TimeSpan GetRemainingDischargeTime()
+	{
+		InitializeAsync(); // TODO
+
+		var remainingDischargeTimeString = WebAssemblyRuntime.InvokeJS($"{JsType}.getRemainingDischargeTime()");
+		if (double.TryParse(remainingDischargeTimeString, out var remainingDischargeTimeInSeconds) &&
+			!double.IsNaN(remainingDischargeTimeInSeconds) &&
+			remainingDischargeTimeInSeconds >= 0)
+		{
+			return TimeSpan.FromSeconds(remainingDischargeTimeInSeconds);
+		}
+
+		return TimeSpan.MaxValue;
+	}
+
+	private static async Task InitializeAsync()
+	{
+		try
+		{
+			await WebAssemblyRuntime.InvokeAsync($"{JsType}.initializeAsync()");
+		}
+		catch (Exception ex)
 		{
-			return batteryStatus;
+			if (typeof(PowerManager).Log().IsEnabled(LogLevel.Error))
+			{
+				typeof(PowerManager).Log().LogError("Could not initialize PowerManager", ex);
+			}
 		}
-		return BatteryStatus.NotPresent;
 	}
 }