SEBWIN-342: Removed UI dependencies from power supply system component.

SafeExamBrowser.Client.UnitTests/Operations/ShellOperationTests.cs

@@ -17,6 +17,7 @@ using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 using SafeExamBrowser.WindowsApi.Contracts;
@@ -38,8 +39,8 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 		private Mock<IKeyboard> keyboard;
 		private Mock<INotificationInfo> logInfo;
 		private Mock<INotificationController> logController;
+		private Mock<IPowerSupply> powerSupply;
 		// TODO 
-		//private Mock<ISystemComponent<ISystemPowerSupplyControl>> powerSupply;
 		//private Mock<ISystemComponent<ISystemWirelessNetworkControl>> wirelessNetwork;
 		private Mock<ISystemInfo> systemInfo;
 		private Mock<ITaskbar> taskbar;
@@ -61,8 +62,8 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 			keyboard = new Mock<IKeyboard>();
 			logInfo = new Mock<INotificationInfo>();
 			logController = new Mock<INotificationController>();
+			powerSupply = new Mock<IPowerSupply>();
 			// TODO 
-			//powerSupply = new Mock<ISystemComponent<ISystemPowerSupplyControl>>();
 			//wirelessNetwork = new Mock<ISystemComponent<ISystemWirelessNetworkControl>>();
 			systemInfo = new Mock<ISystemInfo>();
 			taskbar = new Mock<ITaskbar>();
@@ -84,9 +85,8 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 				keyboard.Object,
 				logInfo.Object,
 				logController.Object,
+				powerSupply.Object,
 				// TODO 
-				//audio.Object,
-				//powerSupply.Object,
 				//wirelessNetwork.Object,
 				systemInfo.Object,
 				taskbar.Object,
@@ -200,14 +200,14 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 			systemInfo.SetupGet(s => s.HasBattery).Returns(true);
 			uiFactory.Setup(f => f.CreateAudioControl(It.IsAny<IAudio>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
 			uiFactory.Setup(f => f.CreateKeyboardLayoutControl(It.IsAny<IKeyboard>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
-			uiFactory.Setup(f => f.CreatePowerSupplyControl(It.IsAny<Location>())).Returns(new Mock<ISystemPowerSupplyControl>().Object);
+			uiFactory.Setup(f => f.CreatePowerSupplyControl(It.IsAny<IPowerSupply>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
 			uiFactory.Setup(f => f.CreateWirelessNetworkControl(It.IsAny<Location>())).Returns(new Mock<ISystemWirelessNetworkControl>().Object);
 
 			sut.Perform();
 
+			audio.Verify(a => a.Initialize(), Times.Once);
+			powerSupply.Verify(p => p.Initialize(), Times.Once);
 			// TODO 
-			//audio.Verify(a => a.Initialize(), Times.Once);
-			//powerSupply.Verify(p => p.Initialize(), Times.Once);
 			//wirelessNetwork.Verify(w => w.Initialize(), Times.Once);
 			keyboard.Verify(k => k.Initialize(), Times.Once);
 			actionCenter.Verify(a => a.AddSystemControl(It.IsAny<ISystemControl>()), Times.Exactly(4));
@@ -229,14 +229,14 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 			systemInfo.SetupGet(s => s.HasBattery).Returns(false);
 			uiFactory.Setup(f => f.CreateAudioControl(It.IsAny<IAudio>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
 			uiFactory.Setup(f => f.CreateKeyboardLayoutControl(It.IsAny<IKeyboard>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
-			uiFactory.Setup(f => f.CreatePowerSupplyControl(It.IsAny<Location>())).Returns(new Mock<ISystemPowerSupplyControl>().Object);
+			uiFactory.Setup(f => f.CreatePowerSupplyControl(It.IsAny<IPowerSupply>(), It.IsAny<Location>())).Returns(new Mock<ISystemControl>().Object);
 			uiFactory.Setup(f => f.CreateWirelessNetworkControl(It.IsAny<Location>())).Returns(new Mock<ISystemWirelessNetworkControl>().Object);
 
 			sut.Perform();
 
+			audio.Verify(a => a.Initialize(), Times.Once);
+			powerSupply.Verify(p => p.Initialize(), Times.Once);
 			// TODO 
-			//audio.Verify(a => a.Initialize(), Times.Once);
-			//powerSupply.Verify(p => p.Initialize(), Times.Once);
 			//wirelessNetwork.Verify(w => w.Initialize(), Times.Once);
 			keyboard.Verify(k => k.Initialize(), Times.Once);
 			actionCenter.Verify(a => a.AddSystemControl(It.IsAny<ISystemControl>()), Times.Never);
@@ -292,11 +292,11 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 			sut.Revert();
 
 			aboutController.Verify(c => c.Terminate(), Times.Once);
+			audio.Verify(a => a.Terminate(), Times.Once);
 			logController.Verify(c => c.Terminate(), Times.Once);
-			// TODO 
+			powerSupply.Verify(p => p.Terminate(), Times.Once);
-			//audio.Verify(a => a.Terminate(), Times.Once);
 			keyboard.Verify(k => k.Terminate(), Times.Once);
-			//powerSupply.Verify(p => p.Terminate(), Times.Once);
+			// TODO 
 			//wirelessNetwork.Verify(w => w.Terminate(), Times.Once);
 		}
 	}

SafeExamBrowser.Client/CompositionRoot.cs

@@ -42,6 +42,7 @@ using SafeExamBrowser.SystemComponents;
 using SafeExamBrowser.SystemComponents.Audio;
 using SafeExamBrowser.SystemComponents.Contracts;
 using SafeExamBrowser.SystemComponents.Keyboard;
+using SafeExamBrowser.SystemComponents.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.MessageBox;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
@@ -257,11 +258,11 @@ namespace SafeExamBrowser.Client
 		{
 			var aboutInfo = new AboutNotificationInfo(text);
 			var aboutController = new AboutNotificationController(configuration.AppConfig, uiFactory);
-			var audio = new Audio(configuration.Settings.Audio, new ModuleLogger(logger, nameof(Audio)), text);
+			var audio = new Audio(configuration.Settings.Audio, new ModuleLogger(logger, nameof(Audio)));
-			var keyboard = new Keyboard(new ModuleLogger(logger, nameof(Keyboard)), text);
+			var keyboard = new Keyboard(new ModuleLogger(logger, nameof(Keyboard)));
 			var logInfo = new LogNotificationInfo(text);
 			var logController = new LogNotificationController(logger, uiFactory);
-			var powerSupply = new PowerSupply(new ModuleLogger(logger, nameof(PowerSupply)), text);
+			var powerSupply = new PowerSupply(new ModuleLogger(logger, nameof(PowerSupply)));
 			var wirelessNetwork = new WirelessNetwork(new ModuleLogger(logger, nameof(WirelessNetwork)), text);
 			var activators = new IActionCenterActivator[]
 			{
@@ -279,8 +280,8 @@ namespace SafeExamBrowser.Client
 				keyboard,
 				logInfo,
 				logController,
+				powerSupply,
 				// TODO 
-				//powerSupply,
 				//wirelessNetwork,
 				systemInfo,
 				taskbar,

SafeExamBrowser.Client/Operations/ShellOperation.cs

@@ -16,6 +16,7 @@ using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 using SafeExamBrowser.WindowsApi.Contracts;
@@ -34,7 +35,7 @@ namespace SafeExamBrowser.Client.Operations
 		private IKeyboard keyboard;
 		private INotificationInfo logInfo;
 		private INotificationController logController;
-		// TODO private ISystemComponent<ISystemPowerSupplyControl> powerSupply;
+		private IPowerSupply powerSupply;
 		// TODO private ISystemComponent<ISystemWirelessNetworkControl> wirelessNetwork;
 		private ISystemInfo systemInfo;
 		private ITaskbar taskbar;
@@ -57,7 +58,7 @@ namespace SafeExamBrowser.Client.Operations
 			IKeyboard keyboard,
 			INotificationInfo logInfo,
 			INotificationController logController,
-			// TODO ISystemComponent<ISystemPowerSupplyControl> powerSupply,
+			IPowerSupply powerSupply,
 			// TODO ISystemComponent<ISystemWirelessNetworkControl> wirelessNetwork,
 			ISystemInfo systemInfo,
 			ITaskbar taskbar,
@@ -76,7 +77,7 @@ namespace SafeExamBrowser.Client.Operations
 			this.logger = logger;
 			this.logInfo = logInfo;
 			this.logController = logController;
-			// TODO this.powerSupply = powerSupply;
+			this.powerSupply = powerSupply;
 			this.systemInfo = systemInfo;
 			this.taskbarSettings = taskbarSettings;
 			this.terminationActivator = terminationActivator;
@@ -171,8 +172,8 @@ namespace SafeExamBrowser.Client.Operations
 		{
 			audio.Initialize();
 			keyboard.Initialize();
+			powerSupply.Initialize();
 			// TODO 
-			//powerSupply.Initialize();
 			//wirelessNetwork.Initialize();
 		}
 
@@ -266,10 +267,7 @@ namespace SafeExamBrowser.Client.Operations
 		{
 			if (systemInfo.HasBattery)
 			{
-				var control = uiFactory.CreatePowerSupplyControl(Location.ActionCenter);
+				actionCenter.AddSystemControl(uiFactory.CreatePowerSupplyControl(powerSupply, Location.ActionCenter));
-
-				// TODO powerSupply.Register(control);
-				actionCenter.AddSystemControl(control);
 			}
 		}
 
@@ -277,10 +275,7 @@ namespace SafeExamBrowser.Client.Operations
 		{
 			if (systemInfo.HasBattery)
 			{
-				var control = uiFactory.CreatePowerSupplyControl(Location.Taskbar);
+				taskbar.AddSystemControl(uiFactory.CreatePowerSupplyControl(powerSupply, Location.Taskbar));
-
-				// TODO powerSupply.Register(control);
-				taskbar.AddSystemControl(control);
 			}
 		}
 
@@ -329,8 +324,8 @@ namespace SafeExamBrowser.Client.Operations
 		{
 			audio.Terminate();
 			keyboard.Terminate();
+			powerSupply.Terminate();
 			// TODO 
-			//powerSupply.Terminate();
 			//wirelessNetwork.Terminate();
 		}
 	}

SafeExamBrowser.SystemComponents.Contracts/PowerSupply/BatteryChargeStatus.cs

@@ -6,10 +6,10 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-namespace SafeExamBrowser.SystemComponents.Contracts
+namespace SafeExamBrowser.SystemComponents.Contracts.PowerSupply
 {
 	/// <summary>
-	/// Defines all possible charge statuses which can be determined by the application.
+	/// Defines all possible battery charge statuses which can be determined by the application.
 	/// </summary>
 	public enum BatteryChargeStatus
 	{

SafeExamBrowser.SystemComponents.Contracts/PowerSupply/Events/PowerSupplyStatusChangedEventHandler.cs

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+namespace SafeExamBrowser.SystemComponents.Contracts.PowerSupply.Events
+{
+	/// <summary>
+	/// Indicates that the status of the power supply for the system has changed.
+	/// </summary>
+	public delegate void PowerSupplyStatusChangedEventHandler(IPowerSupplyStatus status);
+}

SafeExamBrowser.SystemComponents.Contracts/PowerSupply/IPowerSupply.cs

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply.Events;
+
+namespace SafeExamBrowser.SystemComponents.Contracts.PowerSupply
+{
+	/// <summary>
+	/// Defines the functionality of the power supply.
+	/// </summary>
+	public interface IPowerSupply : ISystemComponent
+	{
+		/// <summary>
+		/// Fired when the status of the power supply changed.
+		/// </summary>
+		event PowerSupplyStatusChangedEventHandler StatusChanged;
+
+		/// <summary>
+		/// Retrieves the current status of the power supply.
+		/// </summary>
+		IPowerSupplyStatus GetStatus();
+	}
+}

SafeExamBrowser.SystemComponents.Contracts/PowerSupply/IPowerSupplyStatus.cs

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+
+namespace SafeExamBrowser.SystemComponents.Contracts.PowerSupply
+{
+	/// <summary>
+	/// Provides data about the power supply of the system.
+	/// </summary>
+	public interface IPowerSupplyStatus
+	{
+		/// <summary>
+		/// Defines the current charge of the system battery: <c>0.0</c> means the battery is empty, <c>1.0</c> means it's fully charged.
+		/// </summary>
+		double BatteryCharge { get; }
+
+		/// <summary>
+		/// Defines the current charge status of the system battery.
+		/// </summary>
+		BatteryChargeStatus BatteryChargeStatus { get; }
+
+		/// <summary>
+		/// Defines the time remaining until the battery is empty.
+		/// </summary>
+		TimeSpan BatteryTimeRemaining { get; }
+
+		/// <summary>
+		/// Indicates whether the system is connected to the power grid.
+		/// </summary>
+		bool IsOnline { get; }
+	}
+}

SafeExamBrowser.SystemComponents.Contracts/SafeExamBrowser.SystemComponents.Contracts.csproj

@@ -55,7 +55,9 @@
   <ItemGroup>
     <Compile Include="Audio\Events\AudioVolumeChangedEventHandler.cs" />
     <Compile Include="Audio\IAudio.cs" />
-    <Compile Include="BatteryChargeStatus.cs" />
+    <Compile Include="PowerSupply\Events\PowerSupplyStatusChangedEventHandler.cs" />
+    <Compile Include="PowerSupply\IPowerSupply.cs" />
+    <Compile Include="PowerSupply\BatteryChargeStatus.cs" />
     <Compile Include="Keyboard\Events\KeyboardLayoutChangedEventHandler.cs" />
     <Compile Include="Keyboard\IKeyboard.cs" />
     <Compile Include="Keyboard\IKeyboardLayout.cs" />
@@ -64,6 +66,7 @@
     <Compile Include="IUserInfo.cs" />
     <Compile Include="IWirelessNetwork.cs" />
     <Compile Include="OperatingSystem.cs" />
+    <Compile Include="PowerSupply\IPowerSupplyStatus.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="WirelessNetworkStatus.cs" />
   </ItemGroup>

SafeExamBrowser.SystemComponents/Audio/Audio.cs

@@ -10,7 +10,6 @@ using System;
 using System.Linq;
 using NAudio.CoreAudioApi;
 using SafeExamBrowser.Configuration.Contracts.Settings;
-using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Audio.Events;
@@ -19,15 +18,12 @@ namespace SafeExamBrowser.SystemComponents.Audio
 {
 	public class Audio : IAudio
 	{
-		private readonly object @lock = new object();
-
 		private AudioSettings settings;
 		private MMDevice audioDevice;
 		private string audioDeviceFullName;
 		private string audioDeviceShortName;
 		private float originalVolume;
 		private ILogger logger;
-		private IText text;
 
 		public string DeviceFullName => audioDeviceFullName ?? string.Empty;
 		public string DeviceShortName => audioDeviceShortName ?? string.Empty;
@@ -37,11 +33,10 @@ namespace SafeExamBrowser.SystemComponents.Audio
 
 		public event AudioVolumeChangedEventHandler VolumeChanged;
 
-		public Audio(AudioSettings settings, ILogger logger, IText text)
+		public Audio(AudioSettings settings, ILogger logger)
 		{
 			this.settings = settings;
 			this.logger = logger;
-			this.text = text;
 		}
 
 		public void Initialize()
@@ -157,11 +152,8 @@ namespace SafeExamBrowser.SystemComponents.Audio
 
 		private void AudioEndpointVolume_OnVolumeNotification(AudioVolumeNotificationData data)
 		{
-			lock (@lock)
+			logger.Debug($"Volume is set to {data.MasterVolume * 100}%, audio device is {(data.Muted ? "muted" : "not muted")}.");
-			{
+			VolumeChanged?.Invoke(data.MasterVolume, data.Muted);
-				logger.Debug($"Volume is set to {data.MasterVolume * 100}%, audio device is {(data.Muted ? "muted" : "not muted")}.");
-				VolumeChanged?.Invoke(data.MasterVolume, data.Muted);
-			}
 		}
 	}
 }

SafeExamBrowser.SystemComponents/Keyboard/Keyboard.cs

@@ -11,7 +11,6 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
 using System.Windows.Input;
-using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard.Events;
@@ -23,15 +22,13 @@ namespace SafeExamBrowser.SystemComponents.Keyboard
 		private IList<KeyboardLayout> layouts;
 		private ILogger logger;
 		private CultureInfo originalLanguage;
-		private IText text;
 
 		public event KeyboardLayoutChangedEventHandler LayoutChanged;
 
-		public Keyboard(ILogger logger, IText text)
+		public Keyboard(ILogger logger)
 		{
 			this.layouts = new List<KeyboardLayout>();
 			this.logger = logger;
-			this.text = text;
 		}
 
 		public void ActivateLayout(Guid layoutId)

SafeExamBrowser.SystemComponents/PowerSupply.cs

@@ -1,146 +0,0 @@
-/*
- * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
- * 
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- */
-
-using System;
-using System.Timers;
-using SafeExamBrowser.I18n.Contracts;
-using SafeExamBrowser.Logging.Contracts;
-using SafeExamBrowser.SystemComponents.Contracts;
-using PowerLineStatus = System.Windows.Forms.PowerLineStatus;
-using SystemInformation = System.Windows.Forms.SystemInformation;
-
-namespace SafeExamBrowser.SystemComponents
-{
-	public class PowerSupply // TODO: ISystemComponent<ISystemPowerSupplyControl>
-	{
-		private readonly object @lock = new object();
-
-		private bool infoShown, warningShown;
-		private ILogger logger;
-		// TODOprivate IList<ISystemPowerSupplyControl> controls;
-		private IText text;
-		private Timer timer;
-
-		public PowerSupply(ILogger logger, IText text)
-		{
-			// TODOthis.controls = new List<ISystemPowerSupplyControl>();
-			this.logger = logger;
-			this.text = text;
-		}
-
-		public void Initialize()
-		{
-			const int TWO_SECONDS = 2000;
-
-			timer = new Timer(TWO_SECONDS);
-			timer.Elapsed += Timer_Elapsed;
-			timer.AutoReset = true;
-			timer.Start();
-
-			logger.Info("Started monitoring the power supply.");
-		}
-
-		// TODO
-		//public void Register(ISystemPowerSupplyControl control)
-		//{
-		//	lock (@lock)
-		//	{
-		//		controls.Add(control);
-		//	}
-
-		//	UpdateControls();
-		//}
-
-		public void Terminate()
-		{
-			if (timer != null)
-			{
-				timer.Stop();
-				logger.Info("Stopped monitoring the power supply.");
-			}
-
-			// TODO
-			//foreach (var control in controls)
-			//{
-			//	control.Close();
-			//}
-		}
-
-		private void Timer_Elapsed(object sender, ElapsedEventArgs e)
-		{
-			UpdateControls();
-		}
-
-		private void UpdateControls()
-		{
-			lock (@lock)
-			{
-				var charge = SystemInformation.PowerStatus.BatteryLifePercent;
-				var percentage = Math.Round(charge * 100);
-				var status = charge <= 0.4 ? (charge <= 0.2 ? BatteryChargeStatus.Critical : BatteryChargeStatus.Low) : BatteryChargeStatus.Okay;
-				var online = SystemInformation.PowerStatus.PowerLineStatus == PowerLineStatus.Online;
-				var tooltip = string.Empty;
-
-				if (online)
-				{
-					tooltip = text.Get(percentage == 100 ? TextKey.SystemControl_BatteryCharged : TextKey.SystemControl_BatteryCharging);
-					infoShown = false;
-					warningShown = false;
-				}
-				else
-				{
-					var hours = SystemInformation.PowerStatus.BatteryLifeRemaining / 3600;
-					var minutes = (SystemInformation.PowerStatus.BatteryLifeRemaining - (hours * 3600)) / 60;
-
-					HandleBatteryStatus(status);
-
-					tooltip = text.Get(TextKey.SystemControl_BatteryRemainingCharge);
-					tooltip = tooltip.Replace("%%HOURS%%", hours.ToString());
-					tooltip = tooltip.Replace("%%MINUTES%%", minutes.ToString());
-				}
-
-				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
-
-				// TODO
-				//foreach (var control in controls)
-				//{
-				//	control.SetBatteryCharge(charge, status);
-				//	control.SetPowerGridConnection(online);
-				//	control.SetInformation(tooltip);
-				//}
-			}
-		}
-
-		private void HandleBatteryStatus(BatteryChargeStatus status)
-		{
-			if (status == BatteryChargeStatus.Low && !infoShown)
-			{
-				// TODO
-				//foreach (var control in controls)
-				//{
-				//	control.ShowLowBatteryInfo(text.Get(TextKey.SystemControl_BatteryChargeLowInfo));
-				//}
-
-				infoShown = true;
-				logger.Info("Informed the user about low battery charge.");
-			}
-
-			if (status == BatteryChargeStatus.Critical && !warningShown)
-			{
-				// TODO
-				//foreach (var control in controls)
-				//{
-				//	control.ShowCriticalBatteryWarning(text.Get(TextKey.SystemControl_BatteryChargeCriticalWarning));
-				//}
-
-				warningShown = true;
-				logger.Warn("Warned the user about critical battery charge.");
-			}
-		}
-	}
-}

SafeExamBrowser.SystemComponents/PowerSupply/PowerSupply.cs

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Timers;
+using SafeExamBrowser.Logging.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply.Events;
+using PowerLineStatus = System.Windows.Forms.PowerLineStatus;
+using SystemInformation = System.Windows.Forms.SystemInformation;
+
+namespace SafeExamBrowser.SystemComponents.PowerSupply
+{
+	public class PowerSupply : IPowerSupply
+	{
+		private DateTime lastStatusLog;
+		private ILogger logger;
+		private Timer timer;
+
+		public event PowerSupplyStatusChangedEventHandler StatusChanged;
+
+		public PowerSupply(ILogger logger)
+		{
+			this.logger = logger;
+		}
+
+		public IPowerSupplyStatus GetStatus()
+		{
+			var charge = SystemInformation.PowerStatus.BatteryLifePercent;
+			var hours = SystemInformation.PowerStatus.BatteryLifeRemaining / 3600;
+			var minutes = (SystemInformation.PowerStatus.BatteryLifeRemaining - (hours * 3600)) / 60;
+			var status = new PowerSupplyStatus();
+
+			status.BatteryCharge = charge;
+			status.BatteryChargeStatus = charge <= 0.4 ? (charge <= 0.2 ? BatteryChargeStatus.Critical : BatteryChargeStatus.Low) : BatteryChargeStatus.Okay;
+			status.BatteryTimeRemaining = new TimeSpan(hours, minutes, 0);
+			status.IsOnline = SystemInformation.PowerStatus.PowerLineStatus == PowerLineStatus.Online;
+
+			if (lastStatusLog < DateTime.Now.AddMinutes(-1))
+			{
+				logger.Debug($"Power grid is {(status.IsOnline ? "" : "not ")}connected, battery charge at {charge * 100}% ({status.BatteryTimeRemaining}).");
+				lastStatusLog = DateTime.Now;
+			}
+
+			return status;
+		}
+
+		public void Initialize()
+		{
+			const int TWO_SECONDS = 2000;
+
+			timer = new Timer(TWO_SECONDS);
+			timer.Elapsed += Timer_Elapsed;
+			timer.AutoReset = true;
+			timer.Start();
+
+			logger.Info("Started monitoring the power supply.");
+		}
+
+		public void Terminate()
+		{
+			if (timer != null)
+			{
+				timer.Stop();
+				logger.Info("Stopped monitoring the power supply.");
+			}
+		}
+
+		private void Timer_Elapsed(object sender, ElapsedEventArgs e)
+		{
+			StatusChanged?.Invoke(GetStatus());
+		}
+	}
+}

SafeExamBrowser.SystemComponents/PowerSupply/PowerSupplyStatus.cs

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
+
+namespace SafeExamBrowser.SystemComponents.PowerSupply
+{
+	internal class PowerSupplyStatus : IPowerSupplyStatus
+	{
+		public double BatteryCharge { get; set; }
+		public BatteryChargeStatus BatteryChargeStatus { get; set; }
+		public TimeSpan BatteryTimeRemaining { get; set; }
+		public bool IsOnline { get; set; }
+	}
+}

SafeExamBrowser.SystemComponents/SafeExamBrowser.SystemComponents.csproj

@@ -65,7 +65,8 @@
     <Compile Include="Audio\Audio.cs" />
     <Compile Include="Keyboard\KeyboardLayout.cs" />
     <Compile Include="Keyboard\Keyboard.cs" />
-    <Compile Include="PowerSupply.cs" />
+    <Compile Include="PowerSupply\PowerSupply.cs" />
+    <Compile Include="PowerSupply\PowerSupplyStatus.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SystemInfo.cs" />
     <Compile Include="UserInfo.cs" />

SafeExamBrowser.UserInterface.Contracts/IUserInterfaceFactory.cs

@@ -14,6 +14,7 @@ using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts.Browser;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 using SafeExamBrowser.UserInterface.Contracts.Windows;
@@ -73,7 +74,7 @@ namespace SafeExamBrowser.UserInterface.Contracts
 		/// <summary>
 		/// Creates a system control displaying the power supply status of the computer.
 		/// </summary>
-		ISystemPowerSupplyControl CreatePowerSupplyControl(Location location);
+		ISystemControl CreatePowerSupplyControl(IPowerSupply powerSupply, Location location);
 
 		/// <summary>
 		/// Creates a new runtime window which runs on its own thread.

SafeExamBrowser.UserInterface.Contracts/SafeExamBrowser.UserInterface.Contracts.csproj

@@ -75,7 +75,6 @@
     <Compile Include="Shell\IApplicationControl.cs" />
     <Compile Include="Shell\INotificationControl.cs" />
     <Compile Include="Shell\ISystemControl.cs" />
-    <Compile Include="Shell\ISystemPowerSupplyControl.cs" />
     <Compile Include="Shell\ISystemWirelessNetworkControl.cs" />
     <Compile Include="Shell\ITaskbar.cs" />
     <Compile Include="Shell\Location.cs" />

SafeExamBrowser.UserInterface.Contracts/Shell/ISystemPowerSupplyControl.cs

@@ -1,37 +0,0 @@
-/*
- * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
- * 
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- */
-
-namespace SafeExamBrowser.UserInterface.Contracts.Shell
-{
-	/// <summary>
-	/// The control of the power supply system component.
-	/// </summary>
-	public interface ISystemPowerSupplyControl : ISystemControl
-	{
-		// TODO
-		///// <summary>
-		///// Sets the current charge of the system battery: <c>0.0</c> means the battery is empty, <c>1.0</c> means it's fully charged.
-		///// </summary>
-		//void SetBatteryCharge(double charge, BatteryChargeStatus status);
-
-		/// <summary>
-		/// Sets the power supply status, i.e. whether the computer system is connected to the power grid or not.
-		/// </summary>
-		void SetPowerGridConnection(bool connected);
-
-		/// <summary>
-		/// Warns the user that the battery charge is critical.
-		/// </summary>
-		void ShowCriticalBatteryWarning(string warning);
-
-		/// <summary>
-		/// Indicates the user that the battery charge is low.
-		/// </summary>
-		void ShowLowBatteryInfo(string info);
-	}
-}

SafeExamBrowser.UserInterface.Desktop/Controls/ActionCenterPowerSupplyControl.xaml.cs

@@ -6,62 +6,122 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
-using SafeExamBrowser.SystemComponents.Contracts;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 
 namespace SafeExamBrowser.UserInterface.Desktop.Controls
 {
-	public partial class ActionCenterPowerSupplyControl : UserControl, ISystemPowerSupplyControl
+	public partial class ActionCenterPowerSupplyControl : UserControl, ISystemControl
 	{
-		private double BATTERY_CHARGE_MAX_WIDTH;
+		private Brush initialBrush;
+		private bool infoShown, warningShown;
+		private double maxWidth;
+		private IPowerSupply powerSupply;
+		private IText text;
 
-		public ActionCenterPowerSupplyControl()
+		public ActionCenterPowerSupplyControl(IPowerSupply powerSupply, IText text)
 		{
+			this.powerSupply = powerSupply;
+			this.text = text;
+
 			InitializeComponent();
-			BATTERY_CHARGE_MAX_WIDTH = BatteryCharge.Width;
+			InitializePowerSupplyControl();
 		}
 
 		public void Close()
 		{
 		}
 
-		public void SetBatteryCharge(double charge, BatteryChargeStatus status)
-		{
-			Dispatcher.InvokeAsync(() =>
-			{
-				var width = BATTERY_CHARGE_MAX_WIDTH * charge;
-
-				width = width > BATTERY_CHARGE_MAX_WIDTH ? BATTERY_CHARGE_MAX_WIDTH : width;
-				width = width < 0 ? 0 : width;
-
-				BatteryCharge.Width = width;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Low ? Brushes.Orange : BatteryCharge.Fill;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Critical ? Brushes.Red : BatteryCharge.Fill;
-				Warning.Visibility = status == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
-			});
-		}
-
-		public void SetPowerGridConnection(bool connected)
-		{
-			Dispatcher.InvokeAsync(() => PowerPlug.Visibility = connected ? Visibility.Visible : Visibility.Collapsed);
-		}
-
 		public void SetInformation(string text)
 		{
 			Dispatcher.InvokeAsync(() => Text.Text = text);
 		}
 
-		public void ShowCriticalBatteryWarning(string warning)
+		private void InitializePowerSupplyControl()
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = warning);
+			initialBrush = BatteryCharge.Fill;
+			maxWidth = BatteryCharge.Width;
+			powerSupply.StatusChanged += PowerSupply_StatusChanged;
+			UpdateStatus(powerSupply.GetStatus());
 		}
 
-		public void ShowLowBatteryInfo(string info)
+		private void PowerSupply_StatusChanged(IPowerSupplyStatus status)
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = info);
+			Dispatcher.InvokeAsync(() => UpdateStatus(status));
+		}
+
+		private void UpdateStatus(IPowerSupplyStatus status)
+		{
+			var percentage = Math.Round(status.BatteryCharge * 100);
+			var tooltip = string.Empty;
+
+			RenderCharge(status.BatteryCharge, status.BatteryChargeStatus);
+
+			if (status.IsOnline)
+			{
+				infoShown = false;
+				warningShown = false;
+				tooltip = text.Get(percentage == 100 ? TextKey.SystemControl_BatteryCharged : TextKey.SystemControl_BatteryCharging);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+			}
+			else
+			{
+				tooltip = text.Get(TextKey.SystemControl_BatteryRemainingCharge);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+				tooltip = tooltip.Replace("%%HOURS%%", status.BatteryTimeRemaining.Hours.ToString());
+				tooltip = tooltip.Replace("%%MINUTES%%", status.BatteryTimeRemaining.Minutes.ToString());
+
+				HandleBatteryStatus(status.BatteryChargeStatus);
+			}
+
+			if (!infoShown && !warningShown)
+			{
+				Button.ToolTip = tooltip;
+			}
+
+			PowerPlug.Visibility = status.IsOnline ? Visibility.Visible : Visibility.Collapsed;
+			Text.Text = tooltip;
+			Warning.Visibility = status.BatteryChargeStatus == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
+		}
+
+		private void RenderCharge(double charge, BatteryChargeStatus status)
+		{
+			var width = maxWidth * charge;
+
+			BatteryCharge.Width = width > maxWidth ? maxWidth : (width < 0 ? 0 : width);
+
+			switch (status)
+			{
+				case BatteryChargeStatus.Critical:
+					BatteryCharge.Fill = Brushes.Red;
+					break;
+				case BatteryChargeStatus.Low:
+					BatteryCharge.Fill = Brushes.Orange;
+					break;
+				default:
+					BatteryCharge.Fill = initialBrush;
+					break;
+			}
+		}
+
+		private void HandleBatteryStatus(BatteryChargeStatus chargeStatus)
+		{
+			if (chargeStatus == BatteryChargeStatus.Low && !infoShown)
+			{
+				Button.ToolTip = text.Get(TextKey.SystemControl_BatteryChargeLowInfo);
+				infoShown = true;
+			}
+
+			if (chargeStatus == BatteryChargeStatus.Critical && !warningShown)
+			{
+				Button.ToolTip = text.Get(TextKey.SystemControl_BatteryChargeCriticalWarning);
+				warningShown = true;
+			}
 		}
 	}
 }

SafeExamBrowser.UserInterface.Desktop/Controls/TaskbarPowerSupplyControl.xaml.cs

@@ -6,64 +6,126 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
 using System.Windows.Threading;
-using SafeExamBrowser.SystemComponents.Contracts;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 
 namespace SafeExamBrowser.UserInterface.Desktop.Controls
 {
-	public partial class TaskbarPowerSupplyControl : UserControl, ISystemPowerSupplyControl
+	public partial class TaskbarPowerSupplyControl : UserControl, ISystemControl
 	{
-		private double BATTERY_CHARGE_MAX_WIDTH;
+		private Brush initialBrush;
+		private bool infoShown, warningShown;
+		private double maxWidth;
+		private IPowerSupply powerSupply;
+		private IText text;
 
-		public TaskbarPowerSupplyControl()
+		public TaskbarPowerSupplyControl(IPowerSupply powerSupply, IText text)
 		{
+			this.powerSupply = powerSupply;
+			this.text = text;
+
 			InitializeComponent();
-			BATTERY_CHARGE_MAX_WIDTH = BatteryCharge.Width;
+			InitializePowerSupplyControl();
 		}
 
 		public void Close()
 		{
-			Popup.IsOpen = false;
+			Dispatcher.InvokeAsync(ClosePopup);
-		}
-
-		public void SetBatteryCharge(double charge, BatteryChargeStatus status)
-		{
-			Dispatcher.InvokeAsync(() =>
-			{
-				var width = BATTERY_CHARGE_MAX_WIDTH * charge;
-
-				width = width > BATTERY_CHARGE_MAX_WIDTH ? BATTERY_CHARGE_MAX_WIDTH : width;
-				width = width < 0 ? 0 : width;
-
-				BatteryCharge.Width = width;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Low ? Brushes.Orange : BatteryCharge.Fill;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Critical ? Brushes.Red : BatteryCharge.Fill;
-				Warning.Visibility = status == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
-			});
-		}
-
-		public void SetPowerGridConnection(bool connected)
-		{
-			Dispatcher.InvokeAsync(() => PowerPlug.Visibility = connected ? Visibility.Visible : Visibility.Collapsed);
 		}
 
 		public void SetInformation(string text)
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = text);
+			Dispatcher.InvokeAsync(() => PopupText.Text = text);
 		}
 
-		public void ShowCriticalBatteryWarning(string warning)
+		private void InitializePowerSupplyControl()
 		{
-			Dispatcher.InvokeAsync(() => ShowPopup(warning));
+			initialBrush = BatteryCharge.Fill;
+			maxWidth = BatteryCharge.Width;
+			powerSupply.StatusChanged += PowerSupply_StatusChanged;
+			UpdateStatus(powerSupply.GetStatus());
 		}
 
-		public void ShowLowBatteryInfo(string info)
+		private void Button_Click(object sender, RoutedEventArgs e)
 		{
-			Dispatcher.InvokeAsync(() => ShowPopup(info));
+			ClosePopup();
+		}
+
+		private void PowerSupply_StatusChanged(IPowerSupplyStatus status)
+		{
+			Dispatcher.InvokeAsync(() => UpdateStatus(status));
+		}
+
+		private void UpdateStatus(IPowerSupplyStatus status)
+		{
+			var percentage = Math.Round(status.BatteryCharge * 100);
+			var tooltip = string.Empty;
+
+			RenderCharge(status.BatteryCharge, status.BatteryChargeStatus);
+
+			if (status.IsOnline)
+			{
+				infoShown = false;
+				warningShown = false;
+				tooltip = text.Get(percentage == 100 ? TextKey.SystemControl_BatteryCharged : TextKey.SystemControl_BatteryCharging);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+
+				ClosePopup();
+			}
+			else
+			{
+				tooltip = text.Get(TextKey.SystemControl_BatteryRemainingCharge);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+				tooltip = tooltip.Replace("%%HOURS%%", status.BatteryTimeRemaining.Hours.ToString());
+				tooltip = tooltip.Replace("%%MINUTES%%", status.BatteryTimeRemaining.Minutes.ToString());
+
+				HandleBatteryStatus(status.BatteryChargeStatus);
+			}
+
+			Button.ToolTip = tooltip;
+			PowerPlug.Visibility = status.IsOnline ? Visibility.Visible : Visibility.Collapsed;
+			Warning.Visibility = status.BatteryChargeStatus == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
+		}
+
+		private void RenderCharge(double charge, BatteryChargeStatus status)
+		{
+			var width = maxWidth * charge;
+
+			BatteryCharge.Width = width > maxWidth ? maxWidth : (width < 0 ? 0 : width);
+
+			switch (status)
+			{
+				case BatteryChargeStatus.Critical:
+					BatteryCharge.Fill = Brushes.Red;
+					break;
+				case BatteryChargeStatus.Low:
+					BatteryCharge.Fill = Brushes.Orange;
+					break;
+				default:
+					BatteryCharge.Fill = initialBrush;
+					break;
+			}
+		}
+
+		private void HandleBatteryStatus(BatteryChargeStatus chargeStatus)
+		{
+			if (chargeStatus == BatteryChargeStatus.Low && !infoShown)
+			{
+				ShowPopup(text.Get(TextKey.SystemControl_BatteryChargeLowInfo));
+				infoShown = true;
+			}
+
+			if (chargeStatus == BatteryChargeStatus.Critical && !warningShown)
+			{
+				ShowPopup(text.Get(TextKey.SystemControl_BatteryChargeCriticalWarning));
+				warningShown = true;
+			}
 		}
 
 		private void ShowPopup(string text)
@@ -73,7 +135,7 @@ namespace SafeExamBrowser.UserInterface.Desktop.Controls
 			Background = Brushes.LightGray;
 		}
 
-		private void Button_Click(object sender, RoutedEventArgs e)
+		private void ClosePopup()
 		{
 			Popup.IsOpen = false;
 			Background = Brushes.Transparent;

SafeExamBrowser.UserInterface.Desktop/UserInterfaceFactory.cs

@@ -18,6 +18,7 @@ using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.Browser;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
@@ -129,15 +130,15 @@ namespace SafeExamBrowser.UserInterface.Desktop
 			return Application.Current.Dispatcher.Invoke(() => new PasswordDialog(text.Get(message), text.Get(title), text));
 		}
 
-		public ISystemPowerSupplyControl CreatePowerSupplyControl(Location location)
+		public ISystemControl CreatePowerSupplyControl(IPowerSupply powerSupply, Location location)
 		{
 			if (location == Location.ActionCenter)
 			{
-				return new ActionCenterPowerSupplyControl();
+				return new ActionCenterPowerSupplyControl(powerSupply, text);
 			}
 			else
 			{
-				return new TaskbarPowerSupplyControl();
+				return new TaskbarPowerSupplyControl(powerSupply, text);
 			}
 		}
 

SafeExamBrowser.UserInterface.Mobile/Controls/ActionCenterPowerSupplyControl.xaml.cs

@@ -6,62 +6,122 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
-using SafeExamBrowser.SystemComponents.Contracts;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 
 namespace SafeExamBrowser.UserInterface.Mobile.Controls
 {
-	public partial class ActionCenterPowerSupplyControl : UserControl, ISystemPowerSupplyControl
+	public partial class ActionCenterPowerSupplyControl : UserControl, ISystemControl
 	{
-		private double BATTERY_CHARGE_MAX_WIDTH;
+		private Brush initialBrush;
+		private bool infoShown, warningShown;
+		private double maxWidth;
+		private IPowerSupply powerSupply;
+		private IText text;
 
-		public ActionCenterPowerSupplyControl()
+		public ActionCenterPowerSupplyControl(IPowerSupply powerSupply, IText text)
 		{
+			this.powerSupply = powerSupply;
+			this.text = text;
+
 			InitializeComponent();
-			BATTERY_CHARGE_MAX_WIDTH = BatteryCharge.Width;
+			InitializePowerSupplyControl();
 		}
 
 		public void Close()
 		{
 		}
 
-		public void SetBatteryCharge(double charge, BatteryChargeStatus status)
-		{
-			Dispatcher.InvokeAsync(() =>
-			{
-				var width = BATTERY_CHARGE_MAX_WIDTH * charge;
-
-				width = width > BATTERY_CHARGE_MAX_WIDTH ? BATTERY_CHARGE_MAX_WIDTH : width;
-				width = width < 0 ? 0 : width;
-
-				BatteryCharge.Width = width;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Low ? Brushes.Orange : BatteryCharge.Fill;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Critical ? Brushes.Red : BatteryCharge.Fill;
-				Warning.Visibility = status == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
-			});
-		}
-
-		public void SetPowerGridConnection(bool connected)
-		{
-			Dispatcher.InvokeAsync(() => PowerPlug.Visibility = connected ? Visibility.Visible : Visibility.Collapsed);
-		}
-
 		public void SetInformation(string text)
 		{
 			Dispatcher.InvokeAsync(() => Text.Text = text);
 		}
 
-		public void ShowCriticalBatteryWarning(string warning)
+		private void InitializePowerSupplyControl()
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = warning);
+			initialBrush = BatteryCharge.Fill;
+			maxWidth = BatteryCharge.Width;
+			powerSupply.StatusChanged += PowerSupply_StatusChanged;
+			UpdateStatus(powerSupply.GetStatus());
 		}
 
-		public void ShowLowBatteryInfo(string info)
+		private void PowerSupply_StatusChanged(IPowerSupplyStatus status)
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = info);
+			Dispatcher.InvokeAsync(() => UpdateStatus(status));
+		}
+
+		private void UpdateStatus(IPowerSupplyStatus status)
+		{
+			var percentage = Math.Round(status.BatteryCharge * 100);
+			var tooltip = string.Empty;
+
+			RenderCharge(status.BatteryCharge, status.BatteryChargeStatus);
+
+			if (status.IsOnline)
+			{
+				infoShown = false;
+				warningShown = false;
+				tooltip = text.Get(percentage == 100 ? TextKey.SystemControl_BatteryCharged : TextKey.SystemControl_BatteryCharging);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+			}
+			else
+			{
+				tooltip = text.Get(TextKey.SystemControl_BatteryRemainingCharge);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+				tooltip = tooltip.Replace("%%HOURS%%", status.BatteryTimeRemaining.Hours.ToString());
+				tooltip = tooltip.Replace("%%MINUTES%%", status.BatteryTimeRemaining.Minutes.ToString());
+
+				HandleBatteryStatus(status.BatteryChargeStatus);
+			}
+
+			if (!infoShown && !warningShown)
+			{
+				Button.ToolTip = tooltip;
+			}
+
+			PowerPlug.Visibility = status.IsOnline ? Visibility.Visible : Visibility.Collapsed;
+			Text.Text = tooltip;
+			Warning.Visibility = status.BatteryChargeStatus == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
+		}
+
+		private void RenderCharge(double charge, BatteryChargeStatus status)
+		{
+			var width = maxWidth * charge;
+
+			BatteryCharge.Width = width > maxWidth ? maxWidth : (width < 0 ? 0 : width);
+
+			switch (status)
+			{
+				case BatteryChargeStatus.Critical:
+					BatteryCharge.Fill = Brushes.Red;
+					break;
+				case BatteryChargeStatus.Low:
+					BatteryCharge.Fill = Brushes.Orange;
+					break;
+				default:
+					BatteryCharge.Fill = initialBrush;
+					break;
+			}
+		}
+
+		private void HandleBatteryStatus(BatteryChargeStatus chargeStatus)
+		{
+			if (chargeStatus == BatteryChargeStatus.Low && !infoShown)
+			{
+				Button.ToolTip = text.Get(TextKey.SystemControl_BatteryChargeLowInfo);
+				infoShown = true;
+			}
+
+			if (chargeStatus == BatteryChargeStatus.Critical && !warningShown)
+			{
+				Button.ToolTip = text.Get(TextKey.SystemControl_BatteryChargeCriticalWarning);
+				warningShown = true;
+			}
 		}
 	}
 }

SafeExamBrowser.UserInterface.Mobile/Controls/TaskbarPowerSupplyControl.xaml.cs

@@ -6,64 +6,126 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
 using System.Windows.Threading;
-using SafeExamBrowser.SystemComponents.Contracts;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
 
 namespace SafeExamBrowser.UserInterface.Mobile.Controls
 {
-	public partial class TaskbarPowerSupplyControl : UserControl, ISystemPowerSupplyControl
+	public partial class TaskbarPowerSupplyControl : UserControl, ISystemControl
 	{
-		private double BATTERY_CHARGE_MAX_WIDTH;
+		private Brush initialBrush;
+		private bool infoShown, warningShown;
+		private double maxWidth;
+		private IPowerSupply powerSupply;
+		private IText text;
 
-		public TaskbarPowerSupplyControl()
+		public TaskbarPowerSupplyControl(IPowerSupply powerSupply, IText text)
 		{
+			this.powerSupply = powerSupply;
+			this.text = text;
+
 			InitializeComponent();
-			BATTERY_CHARGE_MAX_WIDTH = BatteryCharge.Width;
+			InitializePowerSupplyControl();
 		}
 
 		public void Close()
 		{
-			Popup.IsOpen = false;
+			Dispatcher.InvokeAsync(ClosePopup);
-		}
-
-		public void SetBatteryCharge(double charge, BatteryChargeStatus status)
-		{
-			Dispatcher.InvokeAsync(() =>
-			{
-				var width = BATTERY_CHARGE_MAX_WIDTH * charge;
-
-				width = width > BATTERY_CHARGE_MAX_WIDTH ? BATTERY_CHARGE_MAX_WIDTH : width;
-				width = width < 0 ? 0 : width;
-
-				BatteryCharge.Width = width;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Low ? Brushes.Orange : BatteryCharge.Fill;
-				BatteryCharge.Fill = status == BatteryChargeStatus.Critical ? Brushes.Red : BatteryCharge.Fill;
-				Warning.Visibility = status == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
-			});
-		}
-
-		public void SetPowerGridConnection(bool connected)
-		{
-			Dispatcher.InvokeAsync(() => PowerPlug.Visibility = connected ? Visibility.Visible : Visibility.Collapsed);
 		}
 
 		public void SetInformation(string text)
 		{
-			Dispatcher.InvokeAsync(() => Button.ToolTip = text);
+			Dispatcher.InvokeAsync(() => PopupText.Text = text);
 		}
 
-		public void ShowCriticalBatteryWarning(string warning)
+		private void InitializePowerSupplyControl()
 		{
-			Dispatcher.InvokeAsync(() => ShowPopup(warning));
+			initialBrush = BatteryCharge.Fill;
+			maxWidth = BatteryCharge.Width;
+			powerSupply.StatusChanged += PowerSupply_StatusChanged;
+			UpdateStatus(powerSupply.GetStatus());
 		}
 
-		public void ShowLowBatteryInfo(string info)
+		private void Button_Click(object sender, RoutedEventArgs e)
 		{
-			Dispatcher.InvokeAsync(() => ShowPopup(info));
+			ClosePopup();
+		}
+
+		private void PowerSupply_StatusChanged(IPowerSupplyStatus status)
+		{
+			Dispatcher.InvokeAsync(() => UpdateStatus(status));
+		}
+
+		private void UpdateStatus(IPowerSupplyStatus status)
+		{
+			var percentage = Math.Round(status.BatteryCharge * 100);
+			var tooltip = string.Empty;
+
+			RenderCharge(status.BatteryCharge, status.BatteryChargeStatus);
+
+			if (status.IsOnline)
+			{
+				infoShown = false;
+				warningShown = false;
+				tooltip = text.Get(percentage == 100 ? TextKey.SystemControl_BatteryCharged : TextKey.SystemControl_BatteryCharging);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+
+				ClosePopup();
+			}
+			else
+			{
+				tooltip = text.Get(TextKey.SystemControl_BatteryRemainingCharge);
+				tooltip = tooltip.Replace("%%CHARGE%%", percentage.ToString());
+				tooltip = tooltip.Replace("%%HOURS%%", status.BatteryTimeRemaining.Hours.ToString());
+				tooltip = tooltip.Replace("%%MINUTES%%", status.BatteryTimeRemaining.Minutes.ToString());
+
+				HandleBatteryStatus(status.BatteryChargeStatus);
+			}
+
+			Button.ToolTip = tooltip;
+			PowerPlug.Visibility = status.IsOnline ? Visibility.Visible : Visibility.Collapsed;
+			Warning.Visibility = status.BatteryChargeStatus == BatteryChargeStatus.Critical ? Visibility.Visible : Visibility.Collapsed;
+		}
+
+		private void RenderCharge(double charge, BatteryChargeStatus status)
+		{
+			var width = maxWidth * charge;
+
+			BatteryCharge.Width = width > maxWidth ? maxWidth : (width < 0 ? 0 : width);
+
+			switch (status)
+			{
+				case BatteryChargeStatus.Critical:
+					BatteryCharge.Fill = Brushes.Red;
+					break;
+				case BatteryChargeStatus.Low:
+					BatteryCharge.Fill = Brushes.Orange;
+					break;
+				default:
+					BatteryCharge.Fill = initialBrush;
+					break;
+			}
+		}
+
+		private void HandleBatteryStatus(BatteryChargeStatus chargeStatus)
+		{
+			if (chargeStatus == BatteryChargeStatus.Low && !infoShown)
+			{
+				ShowPopup(text.Get(TextKey.SystemControl_BatteryChargeLowInfo));
+				infoShown = true;
+			}
+
+			if (chargeStatus == BatteryChargeStatus.Critical && !warningShown)
+			{
+				ShowPopup(text.Get(TextKey.SystemControl_BatteryChargeCriticalWarning));
+				warningShown = true;
+			}
 		}
 
 		private void ShowPopup(string text)
@@ -73,7 +135,7 @@ namespace SafeExamBrowser.UserInterface.Mobile.Controls
 			Background = Brushes.LightGray;
 		}
 
-		private void Button_Click(object sender, RoutedEventArgs e)
+		private void ClosePopup()
 		{
 			Popup.IsOpen = false;
 			Background = Brushes.Transparent;

SafeExamBrowser.UserInterface.Mobile/UserInterfaceFactory.cs

@@ -18,6 +18,7 @@ using SafeExamBrowser.I18n.Contracts;
 using SafeExamBrowser.Logging.Contracts;
 using SafeExamBrowser.SystemComponents.Contracts.Audio;
 using SafeExamBrowser.SystemComponents.Contracts.Keyboard;
+using SafeExamBrowser.SystemComponents.Contracts.PowerSupply;
 using SafeExamBrowser.UserInterface.Contracts;
 using SafeExamBrowser.UserInterface.Contracts.Browser;
 using SafeExamBrowser.UserInterface.Contracts.Shell;
@@ -129,15 +130,15 @@ namespace SafeExamBrowser.UserInterface.Mobile
 			return Application.Current.Dispatcher.Invoke(() => new PasswordDialog(text.Get(message), text.Get(title), text));
 		}
 
-		public ISystemPowerSupplyControl CreatePowerSupplyControl(Location location)
+		public ISystemControl CreatePowerSupplyControl(IPowerSupply powerSupply, Location location)
 		{
 			if (location == Location.ActionCenter)
 			{
-				return new ActionCenterPowerSupplyControl();
+				return new ActionCenterPowerSupplyControl(powerSupply, text);
 			}
 			else
 			{
-				return new TaskbarPowerSupplyControl();
+				return new TaskbarPowerSupplyControl(powerSupply, text);
 			}
 		}