SEBWIN-303: Started implementing audio control.

SafeExamBrowser.Client.UnitTests/Operations/ShellOperationTests.cs

@@ -34,6 +34,7 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 		private Mock<INotificationController> aboutController;
 		private Mock<INotificationInfo> logInfo;
 		private Mock<INotificationController> logController;
+		private Mock<ISystemComponent<ISystemAudioControl>> audio;
 		private Mock<ISystemComponent<ISystemKeyboardLayoutControl>> keyboardLayout;
 		private Mock<ISystemComponent<ISystemPowerSupplyControl>> powerSupply;
 		private Mock<ISystemComponent<ISystemWirelessNetworkControl>> wirelessNetwork;
@@ -55,6 +56,7 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 			aboutController = new Mock<INotificationController>();
 			logInfo = new Mock<INotificationInfo>();
 			logController = new Mock<INotificationController>();
+			audio = new Mock<ISystemComponent<ISystemAudioControl>>();
 			keyboardLayout = new Mock<ISystemComponent<ISystemKeyboardLayoutControl>>();
 			powerSupply = new Mock<ISystemComponent<ISystemPowerSupplyControl>>();
 			wirelessNetwork = new Mock<ISystemComponent<ISystemWirelessNetworkControl>>();
@@ -76,6 +78,7 @@ namespace SafeExamBrowser.Client.UnitTests.Operations
 				aboutController.Object,
 				logInfo.Object,
 				logController.Object,
+				audio.Object,
 				keyboardLayout.Object,
 				powerSupply.Object,
 				wirelessNetwork.Object,

SafeExamBrowser.Client/CompositionRoot.cs

@@ -67,6 +67,7 @@ namespace SafeExamBrowser.Client
 		private IProcessMonitor processMonitor;
 		private INativeMethods nativeMethods;
 		private IRuntimeProxy runtimeProxy;
+		private ISystemComponent<ISystemAudioControl> audio;
 		private ISystemComponent<ISystemKeyboardLayoutControl> keyboardLayout;
 		private ISystemComponent<ISystemPowerSupplyControl> powerSupply;
 		private ISystemComponent<ISystemWirelessNetworkControl> wirelessNetwork;
@@ -93,6 +94,7 @@ namespace SafeExamBrowser.Client
 			InitializeText();
 
 			actionCenter = BuildActionCenter();
+			audio = new Audio(new ModuleLogger(logger, nameof(Audio)), text);
 			keyboardLayout = new KeyboardLayout(new ModuleLogger(logger, nameof(KeyboardLayout)), text);
 			messageBox = BuildMessageBox();
 			powerSupply = new PowerSupply(new ModuleLogger(logger, nameof(PowerSupply)), text);
@@ -277,6 +279,7 @@ namespace SafeExamBrowser.Client
 				aboutController,
 				logInfo,
 				logController,
+				audio,
 				keyboardLayout,
 				powerSupply,
 				wirelessNetwork,

SafeExamBrowser.Client/Operations/ShellOperation.cs

@@ -30,6 +30,7 @@ namespace SafeExamBrowser.Client.Operations
 		private INotificationController aboutController;
 		private INotificationInfo logInfo;
 		private INotificationController logController;
+		private ISystemComponent<ISystemAudioControl> audio;
 		private ISystemComponent<ISystemKeyboardLayoutControl> keyboardLayout;
 		private ISystemComponent<ISystemPowerSupplyControl> powerSupply;
 		private ISystemComponent<ISystemWirelessNetworkControl> wirelessNetwork;
@@ -52,6 +53,7 @@ namespace SafeExamBrowser.Client.Operations
 			INotificationController aboutController,
 			INotificationInfo logInfo,
 			INotificationController logController,
+			ISystemComponent<ISystemAudioControl> audio,
 			ISystemComponent<ISystemKeyboardLayoutControl> keyboardLayout,
 			ISystemComponent<ISystemPowerSupplyControl> powerSupply,
 			ISystemComponent<ISystemWirelessNetworkControl> wirelessNetwork,
@@ -70,6 +72,7 @@ namespace SafeExamBrowser.Client.Operations
 			this.logger = logger;
 			this.logInfo = logInfo;
 			this.logController = logController;
+			this.audio = audio;
 			this.keyboardLayout = keyboardLayout;
 			this.powerSupply = powerSupply;
 			this.systemInfo = systemInfo;
@@ -128,6 +131,7 @@ namespace SafeExamBrowser.Client.Operations
 				actionCenter.InitializeText(text);
 
 				InitializeAboutNotificationForActionCenter();
+				InitializeAudioForActionCenter();
 				InitializeClockForActionCenter();
 				InitializeLogNotificationForActionCenter();
 				InitializeKeyboardLayoutForActionCenter();
@@ -148,11 +152,12 @@ namespace SafeExamBrowser.Client.Operations
 				taskbar.InitializeText(text);
 
 				InitializeAboutNotificationForTaskbar();
-				InitializeClockForTaskbar();
 				InitializeLogNotificationForTaskbar();
-				InitializeKeyboardLayoutForTaskbar();
-				InitializeWirelessNetworkForTaskbar();
 				InitializePowerSupplyForTaskbar();
+				InitializeWirelessNetworkForTaskbar();
+				InitializeAudioForTaskbar();
+				InitializeKeyboardLayoutForTaskbar();
+				InitializeClockForTaskbar();
 			}
 			else
 			{
@@ -162,6 +167,7 @@ namespace SafeExamBrowser.Client.Operations
 
 		private void InitializeSystemComponents()
 		{
+			audio.Initialize();
 			keyboardLayout.Initialize();
 			powerSupply.Initialize();
 			wirelessNetwork.Initialize();
@@ -189,6 +195,28 @@ namespace SafeExamBrowser.Client.Operations
 			}
 		}
 
+		private void InitializeAudioForActionCenter()
+		{
+			if (actionCenterSettings.ShowAudio)
+			{
+				var control = uiFactory.CreateAudioControl(Location.ActionCenter);
+
+				audio.Register(control);
+				actionCenter.AddSystemControl(control);
+			}
+		}
+
+		private void InitializeAudioForTaskbar()
+		{
+			if (taskbarSettings.ShowAudio)
+			{
+				var control = uiFactory.CreateAudioControl(Location.Taskbar);
+
+				audio.Register(control);
+				taskbar.AddSystemControl(control);
+			}
+		}
+
 		private void InitializeClockForActionCenter()
 		{
 			actionCenter.ShowClock = actionCenterSettings.ShowClock;
@@ -308,6 +336,7 @@ namespace SafeExamBrowser.Client.Operations
 
 		private void TerminateSystemComponents()
 		{
+			audio.Terminate();
 			keyboardLayout.Terminate();
 			powerSupply.Terminate();
 			wirelessNetwork.Terminate();

SafeExamBrowser.Configuration/ConfigurationData/DataMapper.UserInterface.cs

@@ -20,6 +20,15 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 			}
 		}
 
+		private void MapAudio(Settings settings, object value)
+		{
+			if (value is bool show)
+			{
+				settings.ActionCenter.ShowAudio = show;
+				settings.Taskbar.ShowAudio = show;
+			}
+		}
+
 		private void MapClock(Settings settings, object value)
 		{
 			if (value is bool show)

SafeExamBrowser.Configuration/ConfigurationData/DataMapper.cs

@@ -189,6 +189,9 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 		{
 			switch (key)
 			{
+				case Keys.UserInterface.ShowAudio:
+					MapAudio(settings, value);
+					break;
 				case Keys.UserInterface.ShowKeyboardLayout:
 					MapKeyboardLayout(settings, value);
 					break;

SafeExamBrowser.Configuration/ConfigurationData/Keys.cs

@@ -121,6 +121,7 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 
 		internal static class UserInterface
 		{
+			internal const string ShowAudio = "audioControlEnabled";
 			internal const string ShowClock = "showTime";
 			internal const string ShowKeyboardLayout = "showInputLanguage";
 			internal const string ShowWirelessNetwork = "allowWlan";

SafeExamBrowser.Contracts/Configuration/Settings/ActionCenterSettings.cs

@@ -31,6 +31,11 @@ namespace SafeExamBrowser.Contracts.Configuration.Settings
 		/// </summary>
 		public bool ShowApplicationLog { get; set; }
 		
+		/// <summary>
+		/// Determines whether the system control for audio is accessible via the action center.
+		/// </summary>
+		public bool ShowAudio { get; set; }
+
 		/// <summary>
 		/// Determines whether the current date and time will be rendered in the action center.
 		/// </summary>

SafeExamBrowser.Contracts/Configuration/Settings/TaskbarSettings.cs

@@ -31,6 +31,11 @@ namespace SafeExamBrowser.Contracts.Configuration.Settings
 		/// </summary>
 		public bool ShowApplicationLog { get; set; }
 
+		/// <summary>
+		/// Determines whether the system control for audio is accessible via the taskbar.
+		/// </summary>
+		public bool ShowAudio { get; set; }
+
 		/// <summary>
 		/// Determines whether the current date and time will be rendered in the taskbar.
 		/// </summary>

SafeExamBrowser.Contracts/I18n/TextKey.cs

@@ -107,6 +107,9 @@ namespace SafeExamBrowser.Contracts.I18n
 		PasswordDialog_SettingsPasswordRequiredTitle,
 		RuntimeWindow_ApplicationRunning,
 		Shell_QuitButton,
+		SystemControl_AudioDeviceInfo,
+		SystemControl_AudioDeviceInfoMuted,
+		SystemControl_AudioDeviceNotFound,
 		SystemControl_BatteryCharged,
 		SystemControl_BatteryCharging,
 		SystemControl_BatteryChargeCriticalWarning,

SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj

@@ -212,6 +212,7 @@
     <Compile Include="UserInterface\Shell\Events\NotificationControlClickedEventHandler.cs" />
     <Compile Include="UserInterface\Shell\IActionCenter.cs" />
     <Compile Include="UserInterface\Shell\IActionCenterActivator.cs" />
+    <Compile Include="UserInterface\Shell\ISystemAudioControl.cs" />
     <Compile Include="UserInterface\Shell\Location.cs" />
     <Compile Include="UserInterface\Windows\Events\WindowClosingEventHandler.cs" />
     <Compile Include="UserInterface\Shell\Events\WirelessNetworkSelectedEventHandler.cs" />

SafeExamBrowser.Contracts/SystemComponents/ISystemComponent.cs

@@ -11,8 +11,8 @@ using SafeExamBrowser.Contracts.UserInterface.Shell;
 namespace SafeExamBrowser.Contracts.SystemComponents
 {
 	/// <summary>
-	/// Defines the functionality of a system component (e.g. the power supply). Each system component will get an <see cref="ISystemControl"/>
+	/// Defines the functionality of a system component (e.g. the power supply). Each system component can get multiple <see cref="ISystemControl"/>
-	/// assigned, via which the user is able to interact with or get information about the underlying system component.
+	/// assigned, which in turn allow the user to interact with or get information about the underlying system component.
 	/// </summary>
 	public interface ISystemComponent<TControl> where TControl : ISystemControl
 	{

SafeExamBrowser.Contracts/UserInterface/IUserInterfaceFactory.cs

@@ -33,6 +33,11 @@ namespace SafeExamBrowser.Contracts.UserInterface
 		/// </summary>
 		IApplicationControl CreateApplicationControl(IApplicationInfo info, Location location);
 
+		/// <summary>
+		/// Creates a system control which allows to change the audio settings of the computer.
+		/// </summary>
+		ISystemAudioControl CreateAudioControl(Location location);
+
 		/// <summary>
 		/// Creates a new browser window loaded with the given browser control and settings.
 		/// </summary>

SafeExamBrowser.Contracts/UserInterface/Shell/ISystemAudioControl.cs

@@ -0,0 +1,36 @@
+/*
+ * 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.Contracts.UserInterface.Shell
+{
+	/// <summary>
+	/// The control of the audio system component.
+	/// </summary>
+	public interface ISystemAudioControl : ISystemControl
+	{
+		/// <summary>
+		/// Defines whether the computer has an audio output device.
+		/// </summary>
+		bool HasOutputDevice { set; }
+
+		/// <summary>
+		/// Indicates whether the current output device is muted.
+		/// </summary>
+		bool OutputDeviceMuted { set; }
+
+		/// <summary>
+		/// Shows the name of the currently active audio output device.
+		/// </summary>
+		string OutputDeviceName { set; }
+
+		/// <summary>
+		/// Shows the current audio output volume, where <c>0.0</c> is the lowest and <c>1.0</c> the highest possible value.
+		/// </summary>
+		double OutputDeviceVolume { set; }
+	}
+}

SafeExamBrowser.I18n/Text.xml

@@ -279,6 +279,15 @@
     <Entry key="Shell_QuitButton">
         Terminate Session
     </Entry>
+    <Entry key="SystemControl_AudioDeviceInfo">
+        %%NAME%%: %%VOLUME%%%
+    </Entry>
+    <Entry key="SystemControl_AudioDeviceInfoMuted">
+        %%NAME%%: Muted
+    </Entry>
+    <Entry key="SystemControl_AudioDeviceNotFound">
+        No audio device found
+    </Entry>
     <Entry key="SystemControl_BatteryCharging">
         Plugged in, charging... (%%CHARGE%%%)
     </Entry>

SafeExamBrowser.SystemComponents/Audio.cs

@@ -0,0 +1,162 @@
+/*
+ * 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.Collections.Generic;
+using System.Linq;
+using NAudio.CoreAudioApi;
+using SafeExamBrowser.Contracts.I18n;
+using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Contracts.SystemComponents;
+using SafeExamBrowser.Contracts.UserInterface.Shell;
+
+namespace SafeExamBrowser.SystemComponents
+{
+	public class Audio : ISystemComponent<ISystemAudioControl>
+	{
+		private readonly object @lock = new object();
+
+		private MMDevice audioDevice;
+		private string audioDeviceShortName;
+		private List<ISystemAudioControl> controls;
+		private ILogger logger;
+		private IText text;
+
+		public Audio(ILogger logger, IText text)
+		{
+			this.controls = new List<ISystemAudioControl>();
+			this.logger = logger;
+			this.text = text;
+		}
+
+		public void Initialize()
+		{
+			if (TryLoadAudioDevice())
+			{
+				InitializeAudioDevice();
+				InitializeSettings();
+			}
+			else
+			{
+				logger.Warn("Could not find an active audio device!");
+			}
+		}
+
+		public void Register(ISystemAudioControl control)
+		{
+			lock (@lock)
+			{
+				controls.Add(control);
+			}
+
+			UpdateControls();
+		}
+
+		public void Terminate()
+		{
+			if (audioDevice != default(MMDevice))
+			{
+				audioDevice.AudioEndpointVolume.OnVolumeNotification -= AudioEndpointVolume_OnVolumeNotification;
+				audioDevice.Dispose();
+				logger.Info("Stopped monitoring the audio device.");
+			}
+
+			foreach (var control in controls)
+			{
+				control.Close();
+			}
+		}
+
+		private bool TryLoadAudioDevice()
+		{
+			using (var enumerator = new MMDeviceEnumerator())
+			{
+				if (enumerator.HasDefaultAudioEndpoint(DataFlow.Render, Role.Console))
+				{
+					audioDevice = enumerator.GetDefaultAudioEndpoint(DataFlow.Render, Role.Console);
+				}
+				else
+				{
+					audioDevice = enumerator.EnumerateAudioEndPoints(DataFlow.Render, DeviceState.Active).FirstOrDefault();
+				}
+			}
+
+			return audioDevice != default(MMDevice);
+		}
+
+		private void InitializeAudioDevice()
+		{
+			logger.Info($"Found '{audioDevice}' to be the active audio device.");
+			audioDevice.AudioEndpointVolume.OnVolumeNotification += AudioEndpointVolume_OnVolumeNotification;
+			audioDeviceShortName = audioDevice.FriendlyName.Length > 25 ? audioDevice.FriendlyName.Split(' ').First() : audioDevice.FriendlyName;
+			logger.Info("Started monitoring the audio device.");
+		}
+
+		private void InitializeSettings()
+		{
+			// TODO: Mute on startup & initial volume!
+		}
+
+		private void AudioEndpointVolume_OnVolumeNotification(AudioVolumeNotificationData data)
+		{
+			lock (@lock)
+			{
+				var info = BuildInfoText(data.MasterVolume, data.Muted);
+
+				foreach (var control in controls)
+				{
+					control.OutputDeviceMuted = data.Muted;
+					control.OutputDeviceVolume = data.MasterVolume;
+					control.SetInformation(info);
+				}
+			}
+		}
+
+		private void UpdateControls()
+		{
+			lock (@lock)
+			{
+				try
+				{
+					var info = BuildInfoText(audioDevice.AudioEndpointVolume.MasterVolumeLevelScalar, audioDevice.AudioEndpointVolume.Mute);
+
+					foreach (var control in controls)
+					{
+						if (audioDevice != default(MMDevice))
+						{
+							control.HasOutputDevice = true;
+							control.OutputDeviceMuted = audioDevice.AudioEndpointVolume.Mute;
+							control.OutputDeviceName = audioDevice.FriendlyName;
+							control.OutputDeviceVolume = audioDevice.AudioEndpointVolume.MasterVolumeLevelScalar;
+							control.SetInformation(info);
+						}
+						else
+						{
+							control.HasOutputDevice = false;
+							control.SetInformation(text.Get(TextKey.SystemControl_AudioDeviceNotFound));
+						}
+					}
+				}
+				catch (Exception e)
+				{
+					logger.Error("Failed to update audio device status!", e);
+				}
+			}
+		}
+
+		private string BuildInfoText(float volume, bool muted)
+		{
+			var info = text.Get(muted ? TextKey.SystemControl_AudioDeviceInfoMuted : TextKey.SystemControl_AudioDeviceInfo);
+
+			info = info.Replace("%%NAME%%", audioDeviceShortName);
+			info = info.Replace("%%VOLUME%%", Convert.ToString(volume * 100));
+
+			return info;
+		}
+	}
+}

SafeExamBrowser.SystemComponents/SafeExamBrowser.SystemComponents.csproj

@@ -48,6 +48,9 @@
     <ErrorReport>prompt</ErrorReport>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="NAudio, Version=1.9.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\NAudio.1.9.0\lib\net35\NAudio.dll</HintPath>
+    </Reference>
     <Reference Include="PresentationCore" />
     <Reference Include="SimpleWifi, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
@@ -59,6 +62,7 @@
     <Reference Include="System.Windows.Forms" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Audio.cs" />
     <Compile Include="KeyboardLayoutDefinition.cs" />
     <Compile Include="KeyboardLayout.cs" />
     <Compile Include="PowerSupply.cs" />
@@ -74,5 +78,8 @@
       <Name>SafeExamBrowser.Contracts</Name>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

SafeExamBrowser.SystemComponents/packages.config

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="NAudio" version="1.9.0" targetFramework="net472" />
+</packages>

SafeExamBrowser.UserInterface.Desktop/Controls/TaskbarAudioControl.xaml

@@ -0,0 +1,37 @@
+<UserControl x:Class="SafeExamBrowser.UserInterface.Desktop.Controls.TaskbarAudioControl"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:fa="http://schemas.fontawesome.io/icons/"
+             xmlns:local="clr-namespace:SafeExamBrowser.UserInterface.Desktop.Controls"
+             mc:Ignorable="d" d:DesignHeight="40" d:DesignWidth="40">
+    <UserControl.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="../Templates/Buttons.xaml" />
+                <ResourceDictionary Source="../Templates/Colors.xaml" />
+                <ResourceDictionary Source="../Templates/ScrollViewers.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </UserControl.Resources>
+    <Grid>
+        <Popup x:Name="Popup" IsOpen="False" Placement="Top" PlacementTarget="{Binding ElementName=Button}">
+            <Border Background="LightGray" BorderBrush="Gray" BorderThickness="0.75,0.75,0.75,0">
+                <StackPanel Orientation="Vertical">
+                    <TextBlock x:Name="AudioDeviceName" Margin="5" TextAlignment="Center" />
+                    <StackPanel Orientation="Horizontal" Height="40">
+                        <Button x:Name="Mute" Background="Transparent" Padding="5" Template="{StaticResource TaskbarButton}" Width="40">
+                            <ContentControl x:Name="PopupIcon" />
+                        </Button>
+                        <Slider x:Name="Volume" Grid.Column="1" Orientation="Horizontal" TickFrequency="1" IsSnapToTickEnabled="True" Maximum="100" VerticalAlignment="Center" Width="250" />
+                        <TextBlock Grid.Column="2" FontWeight="DemiBold" FontSize="16" Text="{Binding ElementName=Volume, Path=Value}" TextAlignment="Center" VerticalAlignment="Center" Width="40" />
+                    </StackPanel>
+                </StackPanel>
+            </Border>
+        </Popup>
+        <Button x:Name="Button" Background="Transparent" Padding="5" Template="{StaticResource TaskbarButton}" ToolTipService.ShowOnDisabled="True" Width="40">
+            <ContentControl x:Name="TaskbarIcon" />
+        </Button>
+    </Grid>
+</UserControl>

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

@@ -0,0 +1,135 @@
+/*
+ * 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.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using SafeExamBrowser.Contracts.UserInterface.Shell;
+using SafeExamBrowser.UserInterface.Shared.Utilities;
+
+namespace SafeExamBrowser.UserInterface.Desktop.Controls
+{
+	public partial class TaskbarAudioControl : UserControl, ISystemAudioControl
+	{
+		private bool muted;
+		private XamlIconResource MutedIcon;
+		private XamlIconResource NoDeviceIcon;
+
+		public TaskbarAudioControl()
+		{
+			InitializeComponent();
+			InitializeAudioControl();
+		}
+
+		public bool HasOutputDevice
+		{
+			set
+			{
+				Dispatcher.InvokeAsync(() =>
+				{
+					Button.IsEnabled = value;
+
+					if (!value)
+					{
+						TaskbarIcon.Content = IconResourceLoader.Load(NoDeviceIcon);
+					}
+				});
+			}
+		}
+
+		public bool OutputDeviceMuted
+		{
+			set
+			{
+				Dispatcher.InvokeAsync(() =>
+				{
+					muted = value;
+
+					if (value)
+					{
+						PopupIcon.Content = IconResourceLoader.Load(MutedIcon);
+						TaskbarIcon.Content = IconResourceLoader.Load(MutedIcon);
+					}
+					else
+					{
+						TaskbarIcon.Content = LoadIcon(Volume.Value / 100);
+					}
+				});
+			}
+		}
+
+		public string OutputDeviceName
+		{
+			set
+			{
+				Dispatcher.InvokeAsync(() => AudioDeviceName.Text = value);
+			}
+		}
+
+		public double OutputDeviceVolume
+		{
+			set
+			{
+				Dispatcher.InvokeAsync(() =>
+				{
+					Volume.Value = Math.Round(value * 100);
+
+					if (!muted)
+					{
+						PopupIcon.Content = LoadIcon(value);
+						TaskbarIcon.Content = LoadIcon(value);
+					}
+				});
+			}
+		}
+
+		public void Close()
+		{
+			Popup.IsOpen = false;
+		}
+
+		public void SetInformation(string text)
+		{
+			Dispatcher.InvokeAsync(() => Button.ToolTip = text);
+		}
+
+		private void InitializeAudioControl()
+		{
+			var originalBrush = Button.Background;
+
+			Button.Click += (o, args) => Popup.IsOpen = !Popup.IsOpen;
+			Button.MouseLeave += (o, args) => Task.Delay(250).ContinueWith(_ => Dispatcher.Invoke(() => Popup.IsOpen = Popup.IsMouseOver));
+			MutedIcon = new XamlIconResource(new Uri("pack://application:,,,/SafeExamBrowser.UserInterface.Desktop;component/Images/AudioMuted.xaml"));
+			NoDeviceIcon = new XamlIconResource(new Uri("pack://application:,,,/SafeExamBrowser.UserInterface.Desktop;component/Images/AudioNoDevice.xaml"));
+			Popup.MouseLeave += (o, args) => Task.Delay(250).ContinueWith(_ => Dispatcher.Invoke(() => Popup.IsOpen = IsMouseOver));
+
+			Popup.Opened += (o, args) =>
+			{
+				Background = Brushes.LightGray;
+				Button.Background = Brushes.LightGray;
+			};
+
+			Popup.Closed += (o, args) =>
+			{
+				Background = originalBrush;
+				Button.Background = originalBrush;
+			};
+		}
+
+		private UIElement LoadIcon(double volume)
+		{
+			var icon = volume > 0.66 ? "100" : (volume > 0.33 ? "66" : "33");
+			var uri = new Uri($"pack://application:,,,/SafeExamBrowser.UserInterface.Desktop;component/Images/Audio_{icon}.xaml");
+			var resource = new XamlIconResource(uri);
+
+			return IconResourceLoader.Load(resource);
+		}
+	}
+}

SafeExamBrowser.UserInterface.Desktop/Images/AudioMuted.xaml

@@ -0,0 +1,12 @@
+<Viewbox
+  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+  xmlns:fa="http://schemas.fontawesome.io/icons/"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid>
+        <fa:ImageAwesome Icon="VolumeOff" HorizontalAlignment="Left" />
+        <Canvas Width="100" Height="100">
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 60,35 L 90,65"/>
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 60,65 L 90,35"/>
+        </Canvas>
+    </Grid>
+</Viewbox>

SafeExamBrowser.UserInterface.Desktop/Images/AudioNoDevice.xaml

@@ -0,0 +1,16 @@
+<Viewbox
+  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+  xmlns:fa="http://schemas.fontawesome.io/icons/"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid Margin="1">
+        <Grid Margin="5,0,0,0">
+            <fa:ImageAwesome Icon="VolumeOff" Foreground="DarkGray" HorizontalAlignment="Left" />
+            <Canvas Width="100" Height="100">
+                <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 55,35 C 65,45 65,55 55,65"/>
+                <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 65,25 C 80,35 80,65 65,75"/>
+                <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 75,15 C 95,30 95,70 75,85"/>
+            </Canvas>
+        </Grid>
+        <fa:ImageAwesome Foreground="Red" Icon="Ban" Opacity="0.3" />
+    </Grid>
+</Viewbox>

SafeExamBrowser.UserInterface.Desktop/Images/Audio_100.xaml

@@ -0,0 +1,13 @@
+<Viewbox
+  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+  xmlns:fa="http://schemas.fontawesome.io/icons/"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid>
+        <fa:ImageAwesome Icon="VolumeOff" HorizontalAlignment="Left" />
+        <Canvas Width="100" Height="100">
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 55,35 C 65,45 65,55 55,65"/>
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 65,25 C 80,35 80,65 65,75"/>
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 75,15 C 95,30 95,70 75,85"/>
+        </Canvas>
+    </Grid>
+</Viewbox>

SafeExamBrowser.UserInterface.Desktop/Images/Audio_33.xaml

@@ -0,0 +1,13 @@
+<Viewbox
+  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+  xmlns:fa="http://schemas.fontawesome.io/icons/"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid>
+        <fa:ImageAwesome Icon="VolumeOff" HorizontalAlignment="Left" />
+        <Canvas Width="100" Height="100">
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 55,35 C 65,45 65,55 55,65"/>
+            <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 65,25 C 80,35 80,65 65,75"/>
+            <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 75,15 C 95,30 95,70 75,85"/>
+        </Canvas>
+    </Grid>
+</Viewbox>

SafeExamBrowser.UserInterface.Desktop/Images/Audio_66.xaml

@@ -0,0 +1,13 @@
+<Viewbox
+  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+  xmlns:fa="http://schemas.fontawesome.io/icons/"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid>
+        <fa:ImageAwesome Icon="VolumeOff" HorizontalAlignment="Left" />
+        <Canvas Width="100" Height="100">
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 55,35 C 65,45 65,55 55,65"/>
+            <Path StrokeThickness="5.0" Stroke="Black" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 65,25 C 80,35 80,65 65,75"/>
+            <Path StrokeThickness="5.0" Stroke="DarkGray" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeLineJoin="Round" Data="M 75,15 C 95,30 95,70 75,85"/>
+        </Canvas>
+    </Grid>
+</Viewbox>

SafeExamBrowser.UserInterface.Desktop/SafeExamBrowser.UserInterface.Desktop.csproj

@@ -110,6 +110,9 @@
     <Compile Include="Controls\TaskbarApplicationInstanceButton.xaml.cs">
       <DependentUpon>TaskbarApplicationInstanceButton.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Controls\TaskbarAudioControl.xaml.cs">
+      <DependentUpon>TaskbarAudioControl.xaml</DependentUpon>
+    </Compile>
     <Compile Include="Controls\TaskbarClock.xaml.cs">
       <DependentUpon>TaskbarClock.xaml</DependentUpon>
     </Compile>
@@ -212,6 +215,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="Controls\TaskbarAudioControl.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="Controls\TaskbarClock.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -256,6 +263,26 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Resource>
+    <Resource Include="Images\AudioNoDevice.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Resource>
+    <Resource Include="Images\Audio_66.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Resource>
+    <Resource Include="Images\Audio_33.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Resource>
+    <Resource Include="Images\Audio_100.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Resource>
+    <Resource Include="Images\AudioMuted.xaml">
+      <Generator>MSBuild:Compile</Generator>
+      <SubType>Designer</SubType>
+    </Resource>
     <Page Include="Templates\ScrollViewers.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>

SafeExamBrowser.UserInterface.Desktop/UserInterfaceFactory.cs

@@ -52,6 +52,19 @@ namespace SafeExamBrowser.UserInterface.Desktop
 			}
 		}
 
+		public ISystemAudioControl CreateAudioControl(Location location)
+		{
+			// TODO
+			//if (location == Location.ActionCenter)
+			//{
+			//	return new ActionCenterAudioControl();
+			//}
+			//else
+			{
+				return new TaskbarAudioControl();
+			}
+		}
+
 		public IBrowserWindow CreateBrowserWindow(IBrowserControl control, BrowserSettings settings, bool isMainWindow)
 		{
 			return new BrowserWindow(control, settings, isMainWindow, text);

SafeExamBrowser.UserInterface.Mobile/UserInterfaceFactory.cs

@@ -52,6 +52,12 @@ namespace SafeExamBrowser.UserInterface.Mobile
 			}
 		}
 
+		public ISystemAudioControl CreateAudioControl(Location location)
+		{
+			// TODO
+			throw new System.NotImplementedException();
+		}
+
 		public IBrowserWindow CreateBrowserWindow(IBrowserControl control, BrowserSettings settings, bool isMainWindow)
 		{
 			return new BrowserWindow(control, settings, isMainWindow, text);