SEBWIN-221: Fixed implementation of session sequence to correctly handle initialization, transition and termination of sessions by introducing the SessionContext.

SafeExamBrowser.Communication/Proxies/ServiceProxy.cs

@@ -74,7 +74,7 @@ namespace SafeExamBrowser.Communication.Proxies
 		{
 			if (Ignore)
 			{
-				Logger.Debug($"Skipping {operationName} because the ignore flag is set.");
+				Logger.Debug($"Skipping '{operationName}' operation because the ignore flag is set.");
 			}
 
 			return Ignore;

SafeExamBrowser.Configuration/ConfigurationRepository.cs

@@ -25,86 +25,15 @@ namespace SafeExamBrowser.Configuration
 
 		private AppConfig appConfig;
 
-		public ISessionData CurrentSession { get; private set; }
-		public Settings CurrentSettings { get; private set; }
-		public string ReconfigurationFilePath { get; set; }
-
-		public AppConfig AppConfig
-		{
-			get
-			{
-				if (appConfig == null)
-				{
-					InitializeAppConfig();
-				}
-
-				return appConfig;
-			}
-		}
-
 		public ConfigurationRepository(string executablePath, string programCopyright, string programTitle, string programVersion)
 		{
-			this.executablePath = executablePath ?? throw new ArgumentNullException(nameof(executablePath));
+			this.executablePath = executablePath ?? string.Empty;
-			this.programCopyright = programCopyright ?? throw new ArgumentNullException(nameof(programCopyright));
+			this.programCopyright = programCopyright ?? string.Empty;
-			this.programTitle = programTitle ?? throw new ArgumentNullException(nameof(programTitle));
+			this.programTitle = programTitle ?? string.Empty;
-			this.programVersion = programVersion ?? throw new ArgumentNullException(nameof(programVersion));
+			this.programVersion = programVersion ?? string.Empty;
 		}
 
-		public ClientConfiguration BuildClientConfiguration()
+		public AppConfig InitializeAppConfig()
-		{
-			return new ClientConfiguration
-			{
-				AppConfig = AppConfig,
-				SessionId = CurrentSession.Id,
-				Settings = CurrentSettings
-			};
-		}
-
-		public void InitializeSessionConfiguration()
-		{
-			CurrentSession = new SessionData
-			{
-				Id = Guid.NewGuid(),
-				NewDesktop = CurrentSession?.NewDesktop,
-				OriginalDesktop = CurrentSession?.OriginalDesktop,
-				StartupToken = Guid.NewGuid()
-			};
-
-			UpdateAppConfig();
-		}
-
-		public LoadStatus LoadSettings(Uri resource, string settingsPassword = null, string adminPassword = null)
-		{
-			// TODO: Implement loading mechanism
-
-			LoadDefaultSettings();
-
-			return LoadStatus.Success;
-		}
-
-		public void LoadDefaultSettings()
-		{
-			// TODO: Implement default settings
-
-			CurrentSettings = new Settings();
-
-			CurrentSettings.KioskMode = KioskMode.None;
-			CurrentSettings.ServicePolicy = ServicePolicy.Optional;
-
-			CurrentSettings.Browser.StartUrl = "https://www.safeexambrowser.org/testing";
-			CurrentSettings.Browser.AllowAddressBar = true;
-			CurrentSettings.Browser.AllowBackwardNavigation = true;
-			CurrentSettings.Browser.AllowDeveloperConsole = true;
-			CurrentSettings.Browser.AllowForwardNavigation = true;
-			CurrentSettings.Browser.AllowReloading = true;
-			CurrentSettings.Browser.AllowDownloads = true;
-
-			CurrentSettings.Taskbar.AllowApplicationLog = true;
-			CurrentSettings.Taskbar.AllowKeyboardLayout = true;
-			CurrentSettings.Taskbar.AllowWirelessNetwork = true;
-		}
-
-		private void InitializeAppConfig()
 		{
 			var appDataFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), nameof(SafeExamBrowser));
 			var startTime = DateTime.Now;
@@ -134,12 +63,89 @@ namespace SafeExamBrowser.Configuration
 			appConfig.SebUriScheme = "seb";
 			appConfig.SebUriSchemeSecure = "sebs";
 			appConfig.ServiceAddress = $"{BASE_ADDRESS}/service";
+
+			return appConfig;
+		}
+
+		public ISessionConfiguration InitializeSessionConfiguration()
+		{
+			var configuration = new SessionConfiguration();
+
+			UpdateAppConfig();
+
+			configuration.AppConfig = CloneAppConfig();
+			configuration.Id = Guid.NewGuid();
+			configuration.StartupToken = Guid.NewGuid();
+
+			return configuration;
+		}
+
+		public LoadStatus TryLoadSettings(Uri resource, out Settings settings, string adminPassword = null, string settingsPassword = null)
+		{
+			// TODO: Implement loading mechanism
+
+			settings = LoadDefaultSettings();
+
+			return LoadStatus.Success;
+		}
+
+		public Settings LoadDefaultSettings()
+		{
+			// TODO: Implement default settings
+
+			var settings = new Settings();
+
+			settings.KioskMode = new Random().Next(10) < 5 ? KioskMode.CreateNewDesktop : KioskMode.DisableExplorerShell;
+			settings.ServicePolicy = ServicePolicy.Optional;
+
+			settings.Browser.StartUrl = "https://www.safeexambrowser.org/testing";
+			settings.Browser.AllowAddressBar = true;
+			settings.Browser.AllowBackwardNavigation = true;
+			settings.Browser.AllowDeveloperConsole = true;
+			settings.Browser.AllowForwardNavigation = true;
+			settings.Browser.AllowReloading = true;
+			settings.Browser.AllowDownloads = true;
+
+			settings.Taskbar.AllowApplicationLog = true;
+			settings.Taskbar.AllowKeyboardLayout = true;
+			settings.Taskbar.AllowWirelessNetwork = true;
+
+			return settings;
+		}
+
+		private AppConfig CloneAppConfig()
+		{
+			return new AppConfig
+			{
+				AppDataFolder = appConfig.AppDataFolder,
+				ApplicationStartTime = appConfig.ApplicationStartTime,
+				BrowserCachePath = appConfig.BrowserCachePath,
+				BrowserLogFile = appConfig.BrowserLogFile,
+				ClientAddress = appConfig.ClientAddress,
+				ClientExecutablePath = appConfig.ClientExecutablePath,
+				ClientId = appConfig.ClientId,
+				ClientLogFile = appConfig.ClientLogFile,
+				ConfigurationFileExtension = appConfig.ConfigurationFileExtension,
+				DefaultSettingsFileName = appConfig.DefaultSettingsFileName,
+				DownloadDirectory = appConfig.DownloadDirectory,
+				LogLevel = appConfig.LogLevel,
+				ProgramCopyright = appConfig.ProgramCopyright,
+				ProgramDataFolder = appConfig.ProgramDataFolder,
+				ProgramTitle = appConfig.ProgramTitle,
+				ProgramVersion = appConfig.ProgramVersion,
+				RuntimeAddress = appConfig.RuntimeAddress,
+				RuntimeId = appConfig.RuntimeId,
+				RuntimeLogFile = appConfig.RuntimeLogFile,
+				SebUriScheme = appConfig.SebUriScheme,
+				SebUriSchemeSecure = appConfig.SebUriSchemeSecure,
+				ServiceAddress = appConfig.ServiceAddress
+			};
 		}
 
 		private void UpdateAppConfig()
 		{
-			AppConfig.ClientId = Guid.NewGuid();
+			appConfig.ClientId = Guid.NewGuid();
-			AppConfig.ClientAddress = $"{BASE_ADDRESS}/client/{Guid.NewGuid()}";
+			appConfig.ClientAddress = $"{BASE_ADDRESS}/client/{Guid.NewGuid()}";
 		}
 	}
 }

SafeExamBrowser.Configuration/ResourceLoader.cs

@@ -15,7 +15,7 @@ namespace SafeExamBrowser.Configuration
 	{
 		public bool IsHtmlResource(Uri resource)
 		{
-			// TODO
+			// TODO: Implement resource loader
 			return false;
 		}
 	}

SafeExamBrowser.Configuration/SafeExamBrowser.Configuration.csproj

@@ -53,9 +53,9 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ResourceLoader.cs" />
-    <Compile Include="SessionData.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ConfigurationRepository.cs" />
+    <Compile Include="SessionConfiguration.cs" />
     <Compile Include="SystemInfo.cs" />
   </ItemGroup>
   <ItemGroup>

SafeExamBrowser.Configuration/SessionConfiguration.cs

@@ -7,19 +7,16 @@
  */
 
 using System;
-using SafeExamBrowser.Contracts.Communication.Proxies;
 using SafeExamBrowser.Contracts.Configuration;
-using SafeExamBrowser.Contracts.WindowsApi;
+using SafeExamBrowser.Contracts.Configuration.Settings;
 
 namespace SafeExamBrowser.Configuration
 {
-	public class SessionData : ISessionData
+	internal class SessionConfiguration : ISessionConfiguration
 	{
-		public IClientProxy ClientProxy { get; set; }
+		public AppConfig AppConfig { get; set; }
-		public IProcess ClientProcess { get; set; }
 		public Guid Id { get; set; }
-		public IDesktop NewDesktop { get; set; }
+		public Settings Settings { get; set; }
-		public IDesktop OriginalDesktop { get; set; }
 		public Guid StartupToken { get; set; }
 	}
 }

SafeExamBrowser.Contracts/Communication/Events/ClientConfigurationEventArgs.cs

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018 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.Contracts.Configuration;
+
+namespace SafeExamBrowser.Contracts.Communication.Events
+{
+	/// <summary>
+	/// The event arguments used for the client configuration event fired by the <see cref="Hosts.IRuntimeHost"/>.
+	/// </summary>
+	public class ClientConfigurationEventArgs : CommunicationEventArgs
+	{
+		/// <summary>
+		/// The configuration to be sent to the client.
+		/// </summary>
+		public ClientConfiguration ClientConfiguration { get; set; }
+	}
+}

SafeExamBrowser.Contracts/Communication/Hosts/IRuntimeHost.cs

@@ -31,6 +31,11 @@ namespace SafeExamBrowser.Contracts.Communication.Hosts
 		/// </summary>
 		event CommunicationEventHandler ClientReady;
 
+		/// <summary>
+		/// Event fired when the client requested its configuration data.
+		/// </summary>
+		event CommunicationEventHandler<ClientConfigurationEventArgs> ClientConfigurationNeeded;
+
 		/// <summary>
 		/// Event fired when the client submitted a password entered by the user.
 		/// </summary>

SafeExamBrowser.Contracts/Configuration/IConfigurationRepository.cs

@@ -16,46 +16,25 @@ namespace SafeExamBrowser.Contracts.Configuration
 	public interface IConfigurationRepository
 	{
 		/// <summary>
-		/// The global configuration information for the currently running application instance.
+		/// Initializes the global configuration information for the currently running application instance.
 		/// </summary>
-		AppConfig AppConfig { get; }
+		AppConfig InitializeAppConfig();
 
 		/// <summary>
-		/// Retrieves the current session data, i.e. the last one which was initialized. If no session has been initialized yet, this
+		/// Initializes all relevant configuration data for a new session.
-		/// property will be <c>null</c>!
 		/// </summary>
-		ISessionData CurrentSession { get; }
+		ISessionConfiguration InitializeSessionConfiguration();
-
-		/// <summary>
-		/// Retrieves the current settings, i.e. the last ones which were loaded. If no settings have been loaded yet, this property will
-		/// be <c>null</c>!
-		/// </summary>
-		Settings.Settings CurrentSettings { get; }
-
-		/// <summary>
-		/// The path of the settings file to be used when reconfiguring the application.
-		/// </summary>
-		string ReconfigurationFilePath { get; set; }
-
-		/// <summary>
-		/// Builds a configuration for the client component, given the currently loaded settings, session and runtime information.
-		/// </summary>
-		ClientConfiguration BuildClientConfiguration();
-
-		/// <summary>
-		/// Initializes all relevant data for a new session.
-		/// </summary>
-		void InitializeSessionConfiguration();
 
 		/// <summary>
 		/// Attempts to load settings from the specified resource, using the optional passwords. Returns a <see cref="LoadStatus"/>
-		/// indicating the result of the operation.
+		/// indicating the result of the operation. As long as the result is not <see cref="LoadStatus.Success"/>, the declared
+		/// <paramref name="settings"/> will be <c>null</c>!
 		/// </summary>
-		LoadStatus LoadSettings(Uri resource, string adminPassword = null, string settingsPassword = null);
+		LoadStatus TryLoadSettings(Uri resource, out Settings.Settings settings, string adminPassword = null, string settingsPassword = null);
 
 		/// <summary>
 		/// Loads the default settings.
 		/// </summary>
-		void LoadDefaultSettings();
+		Settings.Settings LoadDefaultSettings();
 	}
 }

SafeExamBrowser.Contracts/Configuration/ISessionConfiguration.cs

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2018 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.Contracts.Configuration
+{
+	/// <summary>
+	/// Holds all session-related configuration data.
+	/// </summary>
+	public interface ISessionConfiguration
+	{
+		/// <summary>
+		/// The active application configuration for this session.
+		/// </summary>
+		AppConfig AppConfig { get; }
+
+		/// <summary>
+		/// The unique session identifier.
+		/// </summary>
+		Guid Id { get; }
+
+		/// <summary>
+		/// The settings used for this session.
+		/// </summary>
+		Settings.Settings Settings { get; set; }
+
+		/// <summary>
+		/// The startup token used by the client and runtime components for initial authentication.
+		/// </summary>
+		Guid StartupToken { get; }
+	}
+}

SafeExamBrowser.Contracts/Configuration/ISessionData.cs

@@ -1,50 +0,0 @@
-/*
- * Copyright (c) 2018 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.Contracts.Communication.Proxies;
-using SafeExamBrowser.Contracts.WindowsApi;
-
-namespace SafeExamBrowser.Contracts.Configuration
-{
-	/// <summary>
-	/// Holds all session-related configuration and runtime data.
-	/// </summary>
-	public interface ISessionData
-	{
-		/// <summary>
-		/// The communication proxy for the client instance associated to this session.
-		/// </summary>
-		IClientProxy ClientProxy { get; set; }
-
-		/// <summary>
-		/// The process information of the client instance associated to this session.
-		/// </summary>
-		IProcess ClientProcess { get; set; }
-
-		/// <summary>
-		/// The unique session identifier.
-		/// </summary>
-		Guid Id { get; }
-
-		/// <summary>
-		/// The new desktop, if <see cref="Settings.KioskMode.CreateNewDesktop"/> is active for this session.
-		/// </summary>
-		IDesktop NewDesktop { get; set; }
-
-		/// <summary>
-		/// The original desktop, if <see cref="Settings.KioskMode.CreateNewDesktop"/> is active for this session.
-		/// </summary>
-		IDesktop OriginalDesktop { get; set; }
-
-		/// <summary>
-		/// The startup token used by the client and runtime components for initial authentication.
-		/// </summary>
-		Guid StartupToken { get; }
-	}
-}

SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj

@@ -52,6 +52,7 @@
     <Reference Include="System.ServiceModel" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Communication\Events\ClientConfigurationEventArgs.cs" />
     <Compile Include="Core\Events\InstanceTerminatedEventHandler.cs" />
     <Compile Include="Core\Events\NameChangedEventHandler.cs" />
     <Compile Include="Core\IApplicationController.cs" />
@@ -109,7 +110,7 @@
     <Compile Include="Configuration\IResourceLoader.cs" />
     <Compile Include="Configuration\LoadStatus.cs" />
     <Compile Include="Configuration\AppConfig.cs" />
-    <Compile Include="Configuration\ISessionData.cs" />
+    <Compile Include="Configuration\ISessionConfiguration.cs" />
     <Compile Include="Configuration\Settings\ConfigurationMode.cs" />
     <Compile Include="Core\INotificationController.cs" />
     <Compile Include="Core\OperationModel\IOperation.cs" />

SafeExamBrowser.Runtime/Communication/RuntimeHost.cs

@@ -11,7 +11,6 @@ using SafeExamBrowser.Communication.Hosts;
 using SafeExamBrowser.Contracts.Communication.Data;
 using SafeExamBrowser.Contracts.Communication.Events;
 using SafeExamBrowser.Contracts.Communication.Hosts;
-using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Runtime.Communication
@@ -19,24 +18,18 @@ namespace SafeExamBrowser.Runtime.Communication
 	internal class RuntimeHost : BaseHost, IRuntimeHost
 	{
 		private bool allowConnection = true;
-		private IConfigurationRepository configuration;
 
 		public Guid StartupToken { private get; set; }
 
 		public event CommunicationEventHandler ClientDisconnected;
 		public event CommunicationEventHandler ClientReady;
+		public event CommunicationEventHandler<ClientConfigurationEventArgs> ClientConfigurationNeeded;
 		public event CommunicationEventHandler<PasswordReplyEventArgs> PasswordReceived;
 		public event CommunicationEventHandler<ReconfigurationEventArgs> ReconfigurationRequested;
 		public event CommunicationEventHandler ShutdownRequested;
 
-		public RuntimeHost(
+		public RuntimeHost(string address, IHostObjectFactory factory, ILogger logger, int timeout_ms) : base(address, factory, logger, timeout_ms)
-			string address,
-			IConfigurationRepository configuration,
-			IHostObjectFactory factory,
-			ILogger logger,
-			int timeout_ms) : base(address, factory, logger, timeout_ms)
 		{
-			this.configuration = configuration;
 		}
 
 		protected override bool OnConnect(Guid? token = null)
@@ -87,8 +80,7 @@ namespace SafeExamBrowser.Runtime.Communication
 					ClientReady?.Invoke();
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
 				case SimpleMessagePurport.ConfigurationNeeded:
-					// TODO: Not the job of the host, fire event or alike!
+					return HandleConfigurationRequest();
-					return new ConfigurationResponse { Configuration = configuration.BuildClientConfiguration() };
 				case SimpleMessagePurport.RequestShutdown:
 					ShutdownRequested?.Invoke();
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
@@ -96,5 +88,14 @@ namespace SafeExamBrowser.Runtime.Communication
 
 			return new SimpleResponse(SimpleResponsePurport.UnknownMessage);
 		}
+
+		private Response HandleConfigurationRequest()
+		{
+			var args = new ClientConfigurationEventArgs();
+
+			ClientConfigurationNeeded?.Invoke(args);
+
+			return new ConfigurationResponse { Configuration = args.ClientConfiguration };
+		}
 	}
 }

SafeExamBrowser.Runtime/CompositionRoot.cs

@@ -49,7 +49,7 @@ namespace SafeExamBrowser.Runtime
 			var nativeMethods = new NativeMethods();
 
 			logger = new Logger();
-			appConfig = configuration.AppConfig;
+			appConfig = configuration.InitializeAppConfig();
 			systemInfo = new SystemInfo();
 
 			InitializeLogging();
@@ -61,8 +61,9 @@ namespace SafeExamBrowser.Runtime
 			var processFactory = new ProcessFactory(new ModuleLogger(logger, nameof(ProcessFactory)));
 			var proxyFactory = new ProxyFactory(new ProxyObjectFactory(), logger);
 			var resourceLoader = new ResourceLoader();
-			var runtimeHost = new RuntimeHost(appConfig.RuntimeAddress, configuration, new HostObjectFactory(), new ModuleLogger(logger, nameof(RuntimeHost)), FIVE_SECONDS);
+			var runtimeHost = new RuntimeHost(appConfig.RuntimeAddress, new HostObjectFactory(), new ModuleLogger(logger, nameof(RuntimeHost)), FIVE_SECONDS);
 			var serviceProxy = new ServiceProxy(appConfig.ServiceAddress, new ProxyObjectFactory(), new ModuleLogger(logger, nameof(ServiceProxy)));
+			var sessionContext = new SessionContext();
 			var uiFactory = new UserInterfaceFactory(text);
 
 			var bootstrapOperations = new Queue<IOperation>();
@@ -71,18 +72,19 @@ namespace SafeExamBrowser.Runtime
 			bootstrapOperations.Enqueue(new I18nOperation(logger, text, textResource));
 			bootstrapOperations.Enqueue(new CommunicationHostOperation(runtimeHost, logger));
 
-			sessionOperations.Enqueue(new ConfigurationOperation(appConfig, configuration, logger, resourceLoader, args));
+			sessionOperations.Enqueue(new SessionInitializationOperation(configuration, logger, runtimeHost, sessionContext));
-			sessionOperations.Enqueue(new ClientTerminationOperation(configuration, logger, processFactory, proxyFactory, runtimeHost, FIFTEEN_SECONDS));
+			sessionOperations.Enqueue(new ConfigurationOperation(args, configuration, logger, resourceLoader, sessionContext));
-			sessionOperations.Enqueue(new KioskModeTerminationOperation(configuration, desktopFactory, explorerShell, logger, processFactory));
+			sessionOperations.Enqueue(new ClientTerminationOperation(logger, processFactory, proxyFactory, runtimeHost, sessionContext, FIFTEEN_SECONDS));
-			sessionOperations.Enqueue(new SessionInitializationOperation(configuration, logger, runtimeHost));
+			sessionOperations.Enqueue(new KioskModeTerminationOperation(desktopFactory, explorerShell, logger, processFactory, sessionContext));
-			sessionOperations.Enqueue(new ServiceOperation(configuration, logger, serviceProxy));
+			sessionOperations.Enqueue(new ServiceOperation(logger, serviceProxy, sessionContext));
-			sessionOperations.Enqueue(new KioskModeOperation(configuration, desktopFactory, explorerShell, logger, processFactory));
+			sessionOperations.Enqueue(new KioskModeOperation(desktopFactory, explorerShell, logger, processFactory, sessionContext));
-			sessionOperations.Enqueue(new ClientOperation(configuration, logger, processFactory, proxyFactory, runtimeHost, FIFTEEN_SECONDS));
+			sessionOperations.Enqueue(new ClientOperation(logger, processFactory, proxyFactory, runtimeHost, sessionContext, FIFTEEN_SECONDS));
+			sessionOperations.Enqueue(new SessionActivationOperation(logger, sessionContext));
 
 			var bootstrapSequence = new OperationSequence(logger, bootstrapOperations);
 			var sessionSequence = new RepeatableOperationSequence(logger, sessionOperations);
 
-			RuntimeController = new RuntimeController(appConfig, configuration, logger, messageBox, bootstrapSequence, sessionSequence, runtimeHost, serviceProxy, shutdown, text, uiFactory);
+			RuntimeController = new RuntimeController(appConfig, logger, messageBox, bootstrapSequence, sessionSequence, runtimeHost, serviceProxy, sessionContext, shutdown, text, uiFactory);
 		}
 
 		internal void LogStartupInformation()
@@ -103,7 +105,7 @@ namespace SafeExamBrowser.Runtime
 			logger?.Log($"# Application terminated at {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
 		}
 
-		private ConfigurationRepository BuildConfigurationRepository()
+		private IConfigurationRepository BuildConfigurationRepository()
 		{
 			var executable = Assembly.GetExecutingAssembly();
 			var programCopyright = executable.GetCustomAttribute<AssemblyCopyrightAttribute>().Copyright;

SafeExamBrowser.Runtime/Operations/ClientOperation.cs

@@ -10,7 +10,6 @@ using System.Threading;
 using SafeExamBrowser.Contracts.Communication.Events;
 using SafeExamBrowser.Contracts.Communication.Hosts;
 using SafeExamBrowser.Contracts.Communication.Proxies;
-using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Core.OperationModel.Events;
 using SafeExamBrowser.Contracts.I18n;
@@ -20,40 +19,38 @@ using SafeExamBrowser.Contracts.WindowsApi.Events;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class ClientOperation : IRepeatableOperation
+	internal class ClientOperation : SessionOperation
 	{
 		private readonly int timeout_ms;
 
-		private IConfigurationRepository configuration;
 		private ILogger logger;
 		private IProcessFactory processFactory;
 		private IProxyFactory proxyFactory;
 		private IRuntimeHost runtimeHost;
 
-		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
-		public event StatusChangedEventHandler StatusChanged;
-
 		private IProcess ClientProcess
 		{
-			get { return configuration.CurrentSession.ClientProcess; }
+			get { return Context.ClientProcess; }
-			set { configuration.CurrentSession.ClientProcess = value; }
+			set { Context.ClientProcess = value; }
 		}
 
 		private IClientProxy ClientProxy
 		{
-			get { return configuration.CurrentSession.ClientProxy; }
+			get { return Context.ClientProxy; }
-			set { configuration.CurrentSession.ClientProxy = value; }
+			set { Context.ClientProxy = value; }
 		}
 
+		public override event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public override event StatusChangedEventHandler StatusChanged;
+
 		public ClientOperation(
-			IConfigurationRepository configuration,
 			ILogger logger,
 			IProcessFactory processFactory,
 			IProxyFactory proxyFactory,
 			IRuntimeHost runtimeHost,
-			int timeout_ms)
+			SessionContext sessionContext,
+			int timeout_ms) : base(sessionContext)
 		{
-			this.configuration = configuration;
 			this.logger = logger;
 			this.processFactory = processFactory;
 			this.proxyFactory = proxyFactory;
@@ -61,7 +58,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			this.timeout_ms = timeout_ms;
 		}
 
-		public virtual OperationResult Perform()
+		public override OperationResult Perform()
 		{
 			StatusChanged?.Invoke(TextKey.OperationStatus_StartClient);
 
@@ -79,12 +76,12 @@ namespace SafeExamBrowser.Runtime.Operations
 			return success ? OperationResult.Success : OperationResult.Failed;
 		}
 
-		public virtual OperationResult Repeat()
+		public override OperationResult Repeat()
 		{
 			return Perform();
 		}
 
-		public virtual OperationResult Revert()
+		public override OperationResult Revert()
 		{
 			var success = true;
 
@@ -103,10 +100,10 @@ namespace SafeExamBrowser.Runtime.Operations
 			var clientReadyEvent = new AutoResetEvent(false);
 			var clientReadyEventHandler = new CommunicationEventHandler(() => clientReadyEvent.Set());
 
-			var clientExecutable = configuration.AppConfig.ClientExecutablePath;
+			var clientExecutable = Context.Next.AppConfig.ClientExecutablePath;
-			var clientLogFile = $"{'"' + configuration.AppConfig.ClientLogFile + '"'}";
+			var clientLogFile = $"{'"' + Context.Next.AppConfig.ClientLogFile + '"'}";
-			var hostUri = configuration.AppConfig.RuntimeAddress;
+			var hostUri = Context.Next.AppConfig.RuntimeAddress;
-			var token = configuration.CurrentSession.StartupToken.ToString("D");
+			var token = Context.Next.StartupToken.ToString("D");
 
 			logger.Info("Starting new client process...");
 			runtimeHost.ClientReady += clientReadyEventHandler;
@@ -124,9 +121,9 @@ namespace SafeExamBrowser.Runtime.Operations
 			}
 
 			logger.Info("Client has been successfully started and initialized. Creating communication proxy for client host...");
-			ClientProxy = proxyFactory.CreateClientProxy(configuration.AppConfig.ClientAddress);
+			ClientProxy = proxyFactory.CreateClientProxy(Context.Next.AppConfig.ClientAddress);
 
-			if (!ClientProxy.Connect(configuration.CurrentSession.StartupToken))
+			if (!ClientProxy.Connect(Context.Next.StartupToken))
 			{
 				logger.Error("Failed to connect to client!");
 

SafeExamBrowser.Runtime/Operations/ClientTerminationOperation.cs

@@ -8,22 +8,21 @@
 
 using SafeExamBrowser.Contracts.Communication.Hosts;
 using SafeExamBrowser.Contracts.Communication.Proxies;
-using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Contracts.WindowsApi;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class ClientTerminationOperation : ClientOperation, IRepeatableOperation
+	internal class ClientTerminationOperation : ClientOperation
 	{
 		public ClientTerminationOperation(
-			IConfigurationRepository configuration,
 			ILogger logger,
 			IProcessFactory processFactory,
 			IProxyFactory proxyFactory,
 			IRuntimeHost runtimeHost,
-			int timeout_ms) : base(configuration, logger, processFactory, proxyFactory, runtimeHost, timeout_ms)
+			SessionContext sessionContext,
+			int timeout_ms) : base(logger, processFactory, proxyFactory, runtimeHost, sessionContext, timeout_ms)
 		{
 		}
 

SafeExamBrowser.Runtime/Operations/ConfigurationOperation.cs

@@ -19,32 +19,30 @@ using SafeExamBrowser.Runtime.Operations.Events;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class ConfigurationOperation : IRepeatableOperation
+	internal class ConfigurationOperation : SessionOperation
 	{
+		private string[] commandLineArgs;
 		private IConfigurationRepository configuration;
 		private ILogger logger;
 		private IResourceLoader resourceLoader;
-		private AppConfig appConfig;
-		private string[] commandLineArgs;
 
-		public event ActionRequiredEventHandler ActionRequired;
+		public override event ActionRequiredEventHandler ActionRequired;
-		public event StatusChangedEventHandler StatusChanged;
+		public override event StatusChangedEventHandler StatusChanged;
 
 		public ConfigurationOperation(
-			AppConfig appConfig,
+			string[] commandLineArgs,
 			IConfigurationRepository configuration,
 			ILogger logger,
 			IResourceLoader resourceLoader,
-			string[] commandLineArgs)
+			SessionContext sessionContext) : base(sessionContext)
 		{
-			this.appConfig = appConfig;
+			this.commandLineArgs = commandLineArgs;
 			this.logger = logger;
 			this.configuration = configuration;
 			this.resourceLoader = resourceLoader;
-			this.commandLineArgs = commandLineArgs;
 		}
 
-		public OperationResult Perform()
+		public override OperationResult Perform()
 		{
 			logger.Info("Initializing application configuration...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_InitializeConfiguration);
@@ -69,12 +67,12 @@ namespace SafeExamBrowser.Runtime.Operations
 			return OperationResult.Success;
 		}
 
-		public OperationResult Repeat()
+		public override OperationResult Repeat()
 		{
 			logger.Info("Initializing new application configuration...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_InitializeConfiguration);
 
-			var isValidUri = TryValidateSettingsUri(configuration.ReconfigurationFilePath, out Uri uri);
+			var isValidUri = TryValidateSettingsUri(Context.ReconfigurationFilePath, out Uri uri);
 
 			if (isValidUri)
 			{
@@ -92,7 +90,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			return OperationResult.Failed;
 		}
 
-		public OperationResult Revert()
+		public override OperationResult Revert()
 		{
 			return OperationResult.Success;
 		}
@@ -101,11 +99,12 @@ namespace SafeExamBrowser.Runtime.Operations
 		{
 			var adminPassword = default(string);
 			var settingsPassword = default(string);
+			var settings = default(Settings);
 			var status = default(LoadStatus);
 
 			for (int adminAttempts = 0, settingsAttempts = 0; adminAttempts < 5 && settingsAttempts < 5;)
 			{
-				status = configuration.LoadSettings(uri, adminPassword, settingsPassword);
+				status = configuration.TryLoadSettings(uri, out settings, adminPassword, settingsPassword);
 
 				if (status == LoadStatus.AdminPasswordNeeded || status == LoadStatus.SettingsPasswordNeeded)
 				{
@@ -132,7 +131,15 @@ namespace SafeExamBrowser.Runtime.Operations
 				HandleInvalidData(ref status, uri);
 			}
 
-			return status == LoadStatus.Success ? OperationResult.Success : OperationResult.Failed;
+			if (status == LoadStatus.Success)
+			{
+				Context.Next.Settings = settings;
+
+				return OperationResult.Success;
+			}
+
+
+			return OperationResult.Failed;
 		}
 
 		private PasswordRequiredEventArgs TryGetPassword(LoadStatus status)
@@ -150,7 +157,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			if (resourceLoader.IsHtmlResource(uri))
 			{
 				configuration.LoadDefaultSettings();
-				configuration.CurrentSettings.Browser.StartUrl = uri.AbsoluteUri;
+				Context.Next.Settings.Browser.StartUrl = uri.AbsoluteUri;
 				logger.Info($"The specified URI '{uri.AbsoluteUri}' appears to point to a HTML resource, setting it as startup URL.");
 
 				status = LoadStatus.Success;
@@ -165,8 +172,8 @@ namespace SafeExamBrowser.Runtime.Operations
 		{
 			var path = string.Empty;
 			var isValidUri = false;
-			var programDataSettings = Path.Combine(appConfig.ProgramDataFolder, appConfig.DefaultSettingsFileName);
+			var programDataSettings = Path.Combine(Context.Next.AppConfig.ProgramDataFolder, Context.Next.AppConfig.DefaultSettingsFileName);
-			var appDataSettings = Path.Combine(appConfig.AppDataFolder, appConfig.DefaultSettingsFileName);
+			var appDataSettings = Path.Combine(Context.Next.AppConfig.AppDataFolder, Context.Next.AppConfig.DefaultSettingsFileName);
 
 			uri = null;
 
@@ -206,7 +213,7 @@ namespace SafeExamBrowser.Runtime.Operations
 
 		private void HandleClientConfiguration(ref OperationResult result)
 		{
-			if (result == OperationResult.Success && configuration.CurrentSettings.ConfigurationMode == ConfigurationMode.ConfigureClient)
+			if (result == OperationResult.Success && Context.Next.Settings.ConfigurationMode == ConfigurationMode.ConfigureClient)
 			{
 				var args = new ConfigurationCompletedEventArgs();
 

SafeExamBrowser.Runtime/Operations/KioskModeOperation.cs

@@ -6,7 +6,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Configuration.Settings;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Core.OperationModel.Events;
@@ -16,52 +15,40 @@ using SafeExamBrowser.Contracts.WindowsApi;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class KioskModeOperation : IRepeatableOperation
+	internal class KioskModeOperation : SessionOperation
 	{
-		private IConfigurationRepository configuration;
+		protected IDesktopFactory desktopFactory;
-		private IDesktopFactory desktopFactory;
+		protected IExplorerShell explorerShell;
-		private IExplorerShell explorerShell;
+		protected ILogger logger;
-		private KioskMode kioskMode;
+		protected IProcessFactory processFactory;
-		private ILogger logger;
-		private IProcessFactory processFactory;
 
-		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		private static IDesktop newDesktop;
-		public event StatusChangedEventHandler StatusChanged;
+		private static IDesktop originalDesktop;
 
-		private IDesktop NewDesktop
+		protected static KioskMode? ActiveMode { get; private set; }
-		{
-			get { return configuration.CurrentSession.NewDesktop; }
-			set { configuration.CurrentSession.NewDesktop = value; }
-		}
 
-		private IDesktop OriginalDesktop
+		public override event ActionRequiredEventHandler ActionRequired { add { } remove { } }
-		{
+		public override event StatusChangedEventHandler StatusChanged;
-			get { return configuration.CurrentSession.OriginalDesktop; }
-			set { configuration.CurrentSession.OriginalDesktop = value; }
-		}
 
 		public KioskModeOperation(
-			IConfigurationRepository configuration,
 			IDesktopFactory desktopFactory,
 			IExplorerShell explorerShell,
 			ILogger logger,
-			IProcessFactory processFactory)
+			IProcessFactory processFactory,
+			SessionContext sessionContext) : base(sessionContext)
 		{
-			this.configuration = configuration;
 			this.desktopFactory = desktopFactory;
 			this.explorerShell = explorerShell;
 			this.logger = logger;
 			this.processFactory = processFactory;
 		}
 
-		public virtual OperationResult Perform()
+		public override OperationResult Perform()
 		{
-			kioskMode = configuration.CurrentSettings.KioskMode;
+			logger.Info($"Initializing kiosk mode '{Context.Next.Settings.KioskMode}'...");
-
-			logger.Info($"Initializing kiosk mode '{kioskMode}'...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_InitializeKioskMode);
 
-			switch (kioskMode)
+			switch (Context.Next.Settings.KioskMode)
 			{
 				case KioskMode.CreateNewDesktop:
 					CreateNewDesktop();
@@ -71,17 +58,18 @@ namespace SafeExamBrowser.Runtime.Operations
 					break;
 			}
 
+			ActiveMode = Context.Next.Settings.KioskMode;
+
 			return OperationResult.Success;
 		}
 
-		public virtual OperationResult Repeat()
+		public override OperationResult Repeat()
 		{
-			var oldMode = kioskMode;
+			var newMode = Context.Next.Settings.KioskMode;
-			var newMode = configuration.CurrentSettings.KioskMode;
 
-			if (newMode == oldMode)
+			if (ActiveMode == newMode)
 			{
-				logger.Info($"New kiosk mode '{newMode}' is equal to the currently active '{oldMode}', skipping re-initialization...");
+				logger.Info($"New kiosk mode '{newMode}' is already active, skipping initialization...");
 
 				return OperationResult.Success;
 			}
@@ -89,12 +77,12 @@ namespace SafeExamBrowser.Runtime.Operations
 			return Perform();
 		}
 
-		public virtual OperationResult Revert()
+		public override OperationResult Revert()
 		{
-			logger.Info($"Reverting kiosk mode '{kioskMode}'...");
+			logger.Info($"Reverting kiosk mode '{ActiveMode}'...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_RevertKioskMode);
 
-			switch (kioskMode)
+			switch (ActiveMode)
 			{
 				case KioskMode.CreateNewDesktop:
 					CloseNewDesktop();
@@ -109,14 +97,14 @@ namespace SafeExamBrowser.Runtime.Operations
 
 		private void CreateNewDesktop()
 		{
-			OriginalDesktop = desktopFactory.GetCurrent();
+			originalDesktop = desktopFactory.GetCurrent();
-			logger.Info($"Current desktop is {OriginalDesktop}.");
+			logger.Info($"Current desktop is {originalDesktop}.");
 
-			NewDesktop = desktopFactory.CreateNew(nameof(SafeExamBrowser));
+			newDesktop = desktopFactory.CreateNew(nameof(SafeExamBrowser));
-			logger.Info($"Created new desktop {NewDesktop}.");
+			logger.Info($"Created new desktop {newDesktop}.");
 
-			NewDesktop.Activate();
+			newDesktop.Activate();
-			processFactory.StartupDesktop = NewDesktop;
+			processFactory.StartupDesktop = newDesktop;
 			logger.Info("Successfully activated new desktop.");
 
 			explorerShell.Suspend();
@@ -124,21 +112,21 @@ namespace SafeExamBrowser.Runtime.Operations
 
 		private void CloseNewDesktop()
 		{
-			if (OriginalDesktop != null)
+			if (originalDesktop != null)
 			{
-				OriginalDesktop.Activate();
+				originalDesktop.Activate();
-				processFactory.StartupDesktop = OriginalDesktop;
+				processFactory.StartupDesktop = originalDesktop;
-				logger.Info($"Switched back to original desktop {OriginalDesktop}.");
+				logger.Info($"Switched back to original desktop {originalDesktop}.");
 			}
 			else
 			{
 				logger.Warn($"No original desktop found when attempting to close new desktop!");
 			}
 
-			if (NewDesktop != null)
+			if (newDesktop != null)
 			{
-				NewDesktop.Close();
+				newDesktop.Close();
-				logger.Info($"Closed new desktop {NewDesktop}.");
+				logger.Info($"Closed new desktop {newDesktop}.");
 			}
 			else
 			{
@@ -151,6 +139,9 @@ namespace SafeExamBrowser.Runtime.Operations
 		private void TerminateExplorerShell()
 		{
 			StatusChanged?.Invoke(TextKey.OperationStatus_WaitExplorerTermination);
+
+			// TODO: Hiding all windows must be done here, as the explorer shell is needed to do so!
+
 			explorerShell.Terminate();
 		}
 
@@ -158,6 +149,8 @@ namespace SafeExamBrowser.Runtime.Operations
 		{
 			StatusChanged?.Invoke(TextKey.OperationStatus_WaitExplorerStartup);
 			explorerShell.Start();
+
+			// TODO: Restore all hidden windows!
 		}
 	}
 }

SafeExamBrowser.Runtime/Operations/KioskModeTerminationOperation.cs

@@ -6,8 +6,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Configuration;
-using SafeExamBrowser.Contracts.Configuration.Settings;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Contracts.WindowsApi;
@@ -16,36 +14,27 @@ namespace SafeExamBrowser.Runtime.Operations
 {
 	internal class KioskModeTerminationOperation : KioskModeOperation, IRepeatableOperation
 	{
-		private IConfigurationRepository configuration;
-		private KioskMode kioskMode;
-		private ILogger logger;
-
 		public KioskModeTerminationOperation(
-			IConfigurationRepository configuration,
 			IDesktopFactory desktopFactory,
 			IExplorerShell explorerShell,
 			ILogger logger,
-			IProcessFactory processFactory) : base(configuration, desktopFactory, explorerShell, logger, processFactory)
+			IProcessFactory processFactory,
+			SessionContext sessionContext) : base(desktopFactory, explorerShell, logger, processFactory, sessionContext)
 		{
-			this.configuration = configuration;
-			this.logger = logger;
 		}
 
 		public override OperationResult Perform()
 		{
-			kioskMode = configuration.CurrentSettings.KioskMode;
-
 			return OperationResult.Success;
 		}
 
 		public override OperationResult Repeat()
 		{
-			var oldMode = kioskMode;
+			var newMode = Context.Next.Settings.KioskMode;
-			var newMode = configuration.CurrentSettings.KioskMode;
 
-			if (newMode == oldMode)
+			if (ActiveMode == newMode)
 			{
-				logger.Info($"New kiosk mode '{newMode}' is equal to the currently active '{oldMode}', skipping termination...");
+				logger.Info($"New kiosk mode '{newMode}' is the same as the currently active, skipping termination...");
 
 				return OperationResult.Success;
 			}

SafeExamBrowser.Runtime/Operations/ServiceOperation.cs

@@ -7,7 +7,6 @@
  */
 
 using SafeExamBrowser.Contracts.Communication.Proxies;
-using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Configuration.Settings;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Core.OperationModel.Events;
@@ -16,29 +15,27 @@ using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class ServiceOperation : IRepeatableOperation
+	internal class ServiceOperation : SessionOperation
 	{
 		private bool connected, mandatory;
-		private IConfigurationRepository configuration;
 		private ILogger logger;
 		private IServiceProxy service;
 
-		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public override event ActionRequiredEventHandler ActionRequired { add { } remove { } }
-		public event StatusChangedEventHandler StatusChanged;
+		public override event StatusChangedEventHandler StatusChanged;
 
-		public ServiceOperation(IConfigurationRepository configuration, ILogger logger, IServiceProxy service)
+		public ServiceOperation(ILogger logger, IServiceProxy service, SessionContext sessionContext) : base(sessionContext)
 		{
-			this.configuration = configuration;
-			this.service = service;
 			this.logger = logger;
+			this.service = service;
 		}
 
-		public OperationResult Perform()
+		public override OperationResult Perform()
 		{
 			logger.Info($"Initializing service session...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_InitializeServiceSession);
 
-			mandatory = configuration.CurrentSettings.ServicePolicy == ServicePolicy.Mandatory;
+			mandatory = Context.Next.Settings.ServicePolicy == ServicePolicy.Mandatory;
 			connected = service.Connect();
 
 			if (mandatory && !connected)
@@ -59,7 +56,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			return OperationResult.Success;
 		}
 
-		public OperationResult Repeat()
+		public override OperationResult Repeat()
 		{
 			var result = Revert();
 
@@ -71,7 +68,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			return Perform();
 		}
 
-		public OperationResult Revert()
+		public override OperationResult Revert()
 		{
 			logger.Info("Finalizing service session...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_FinalizeServiceSession);
@@ -97,12 +94,12 @@ namespace SafeExamBrowser.Runtime.Operations
 
 		private void StartServiceSession()
 		{
-			service.StartSession(configuration.CurrentSession.Id, configuration.CurrentSettings);
+			service.StartSession(Context.Next.Id, Context.Next.Settings);
 		}
 
 		private void StopServiceSession()
 		{
-			service.StopSession(configuration.CurrentSession.Id);
+			service.StopSession(Context.Current.Id);
 		}
 	}
 }

SafeExamBrowser.Runtime/Operations/SessionActivationOperation.cs

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2018 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.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Core.OperationModel.Events;
+using SafeExamBrowser.Contracts.Logging;
+
+namespace SafeExamBrowser.Runtime.Operations
+{
+	internal class SessionActivationOperation : SessionOperation
+	{
+		private ILogger logger;
+
+		public override event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public override event StatusChangedEventHandler StatusChanged { add { } remove { } }
+
+		public SessionActivationOperation(ILogger logger, SessionContext sessionContext) : base(sessionContext)
+		{
+			this.logger = logger;
+		}
+
+		public override OperationResult Perform()
+		{
+			ActivateNewSession();
+
+			return OperationResult.Success;
+		}
+
+		public override OperationResult Repeat()
+		{
+			ActivateNewSession();
+
+			return OperationResult.Success;
+		}
+
+		public override OperationResult Revert()
+		{
+			return OperationResult.Success;
+		}
+
+		private void ActivateNewSession()
+		{
+			var isFirstSession = Context.Current == null;
+
+			if (isFirstSession)
+			{
+				logger.Info($"Successfully activated first session '{Context.Next.Id}'.");
+			}
+			else
+			{
+				logger.Info($"Successfully terminated old session '{Context.Current.Id}' and activated new session '{Context.Next.Id}'.");
+			}
+
+			Context.Current = Context.Next;
+			Context.Next = null;
+		}
+	}
+}

SafeExamBrowser.Runtime/Operations/SessionInitializationOperation.cs

@@ -15,35 +15,41 @@ using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
-	internal class SessionInitializationOperation : IRepeatableOperation
+	internal class SessionInitializationOperation : SessionOperation
 	{
 		private IConfigurationRepository configuration;
 		private ILogger logger;
 		private IRuntimeHost runtimeHost;
 
-		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public override event ActionRequiredEventHandler ActionRequired { add { } remove { } }
-		public event StatusChangedEventHandler StatusChanged;
+		public override event StatusChangedEventHandler StatusChanged;
 
-		public SessionInitializationOperation(IConfigurationRepository configuration, ILogger logger, IRuntimeHost runtimeHost)
+		public SessionInitializationOperation(
+			IConfigurationRepository configuration,
+			ILogger logger,
+			IRuntimeHost runtimeHost,
+			SessionContext sessionContext) : base(sessionContext)
 		{
 			this.configuration = configuration;
 			this.logger = logger;
 			this.runtimeHost = runtimeHost;
 		}
 
-		public OperationResult Perform()
+		public override OperationResult Perform()
 		{
 			InitializeSessionConfiguration();
 
 			return OperationResult.Success;
 		}
 
-		public OperationResult Repeat()
+		public override OperationResult Repeat()
 		{
-			return Perform();
+			InitializeSessionConfiguration();
+
+			return OperationResult.Success;
 		}
 
-		public OperationResult Revert()
+		public override OperationResult Revert()
 		{
 			return OperationResult.Success;
 		}
@@ -53,12 +59,12 @@ namespace SafeExamBrowser.Runtime.Operations
 			logger.Info("Initializing new session configuration...");
 			StatusChanged?.Invoke(TextKey.OperationStatus_InitializeSession);
 
-			configuration.InitializeSessionConfiguration();
+			Context.Next = configuration.InitializeSessionConfiguration();
-			runtimeHost.StartupToken = configuration.CurrentSession.StartupToken;
+			runtimeHost.StartupToken = Context.Next.StartupToken;
 
-			logger.Info($" -> Client-ID: {configuration.AppConfig.ClientId}");
+			logger.Info($" -> Client-ID: {Context.Next.AppConfig.ClientId}");
-			logger.Info($" -> Runtime-ID: {configuration.AppConfig.RuntimeId}");
+			logger.Info($" -> Runtime-ID: {Context.Next.AppConfig.RuntimeId}");
-			logger.Info($" -> Session-ID: {configuration.CurrentSession.Id}");
+			logger.Info($" -> Session-ID: {Context.Next.Id}");
 		}
 	}
 }

SafeExamBrowser.Runtime/Operations/SessionOperation.cs

@@ -0,0 +1,25 @@
+using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Core.OperationModel.Events;
+
+namespace SafeExamBrowser.Runtime.Operations
+{
+	/// <summary>
+	/// The base implementation to be used for all operations in the session operation sequence.
+	/// </summary>
+	internal abstract class SessionOperation : IRepeatableOperation
+	{
+		protected SessionContext Context { get; private set; }
+
+		public abstract event ActionRequiredEventHandler ActionRequired;
+		public abstract event StatusChangedEventHandler StatusChanged;
+
+		public SessionOperation(SessionContext sessionContext)
+		{
+			Context = sessionContext;
+		}
+
+		public abstract OperationResult Perform();
+		public abstract OperationResult Repeat();
+		public abstract OperationResult Revert();
+	}
+}

SafeExamBrowser.Runtime/RuntimeController.cs

@@ -28,10 +28,7 @@ namespace SafeExamBrowser.Runtime
 {
 	internal class RuntimeController : IRuntimeController
 	{
-		private bool sessionRunning;
-
 		private AppConfig appConfig;
-		private IConfigurationRepository configuration;
 		private ILogger logger;
 		private IMessageBox messageBox;
 		private IOperationSequence bootstrapSequence;
@@ -39,32 +36,43 @@ namespace SafeExamBrowser.Runtime
 		private IRuntimeHost runtimeHost;
 		private IRuntimeWindow runtimeWindow;
 		private IServiceProxy service;
+		private SessionContext sessionContext;
 		private ISplashScreen splashScreen;
 		private Action shutdown;
 		private IText text;
 		private IUserInterfaceFactory uiFactory;
 		
+		private ISessionConfiguration Session
+		{
+			get { return sessionContext.Current; }
+		}
+
+		private bool SessionIsRunning
+		{
+			get { return Session != null; }
+		}
+
 		public RuntimeController(
 			AppConfig appConfig,
-			IConfigurationRepository configuration,
 			ILogger logger,
 			IMessageBox messageBox,
 			IOperationSequence bootstrapSequence,
 			IRepeatableOperationSequence sessionSequence,
 			IRuntimeHost runtimeHost,
 			IServiceProxy service,
+			SessionContext sessionContext,
 			Action shutdown,
 			IText text,
 			IUserInterfaceFactory uiFactory)
 		{
 			this.appConfig = appConfig;
-			this.configuration = configuration;
 			this.bootstrapSequence = bootstrapSequence;
 			this.logger = logger;
 			this.messageBox = messageBox;
 			this.runtimeHost = runtimeHost;
 			this.sessionSequence = sessionSequence;
 			this.service = service;
+			this.sessionContext = sessionContext;
 			this.shutdown = shutdown;
 			this.text = text;
 			this.uiFactory = uiFactory;
@@ -96,7 +104,7 @@ namespace SafeExamBrowser.Runtime
 				logger.Subscribe(runtimeWindow);
 				splashScreen.Close();
 
-				StartSession(true);
+				StartSession();
 			}
 			else
 			{
@@ -106,14 +114,14 @@ namespace SafeExamBrowser.Runtime
 				messageBox.Show(TextKey.MessageBox_StartupError, TextKey.MessageBox_StartupErrorTitle, icon: MessageBoxIcon.Error, parent: splashScreen);
 			}
 
-			return initialized && sessionRunning;
+			return initialized && SessionIsRunning;
 		}
 
 		public void Terminate()
 		{
 			DeregisterEvents();
 
-			if (sessionRunning)
+			if (SessionIsRunning)
 			{
 				StopSession();
 			}
@@ -145,51 +153,79 @@ namespace SafeExamBrowser.Runtime
 			splashScreen.Close();
 		}
 
-		private void StartSession(bool initial = false)
+		private void StartSession()
 		{
 			runtimeWindow.Show();
 			runtimeWindow.BringToForeground();
 			runtimeWindow.ShowProgressBar();
 			logger.Info("### --- Session Start Procedure --- ###");
 
-			if (sessionRunning)
+			if (SessionIsRunning)
 			{
 				DeregisterSessionEvents();
 			}
 
-			var result = initial ? sessionSequence.TryPerform() : sessionSequence.TryRepeat();
+			var result = SessionIsRunning ? sessionSequence.TryRepeat() : sessionSequence.TryPerform();
 
 			if (result == OperationResult.Success)
 			{
-				RegisterSessionEvents();
-
 				logger.Info("### --- Session Running --- ###");
+
+				HandleSessionStartSuccess();
+			}
+			else if (result == OperationResult.Failed)
+			{
+				logger.Info("### --- Session Start Failed --- ###");
+
+				HandleSessionStartFailure();
+			}
+			else if (result == OperationResult.Aborted)
+			{
+				logger.Info("### --- Session Start Aborted --- ###");
+
+				HandleSessionStartAbortion();
+			}
+		}
+
+		private void HandleSessionStartSuccess()
+		{
+			RegisterSessionEvents();
+
+			runtimeWindow.HideProgressBar();
+			runtimeWindow.UpdateStatus(TextKey.RuntimeWindow_ApplicationRunning);
+			runtimeWindow.TopMost = Session.Settings.KioskMode != KioskMode.None;
+
+			if (Session.Settings.KioskMode == KioskMode.DisableExplorerShell)
+			{
+				runtimeWindow.Hide();
+			}
+		}
+
+		private void HandleSessionStartFailure()
+		{
+			if (SessionIsRunning)
+			{
+				StopSession();
+
+				messageBox.Show(TextKey.MessageBox_SessionStartError, TextKey.MessageBox_SessionStartErrorTitle, icon: MessageBoxIcon.Error, parent: runtimeWindow);
+				logger.Info("Terminating application...");
+
+				shutdown.Invoke();
+			}
+		}
+
+		private void HandleSessionStartAbortion()
+		{
+			if (SessionIsRunning)
+			{
 				runtimeWindow.HideProgressBar();
 				runtimeWindow.UpdateStatus(TextKey.RuntimeWindow_ApplicationRunning);
-				runtimeWindow.TopMost = configuration.CurrentSettings.KioskMode != KioskMode.None;
+				runtimeWindow.TopMost = Session.Settings.KioskMode != KioskMode.None;
 
-				if (configuration.CurrentSettings.KioskMode == KioskMode.DisableExplorerShell)
+				if (Session.Settings.KioskMode == KioskMode.DisableExplorerShell)
 				{
 					runtimeWindow.Hide();
 				}
-
-				sessionRunning = true;
-			}
-			else
-			{
-				logger.Info($"### --- Session Start {(result == OperationResult.Aborted ? "Aborted" : "Failed")} --- ###");
-
-				if (result == OperationResult.Failed)
-				{
-					// TODO: Find solution for this; maybe manually switch back to original desktop?
-					// messageBox.Show(TextKey.MessageBox_SessionStartError, TextKey.MessageBox_SessionStartErrorTitle, icon: MessageBoxIcon.Error, parent: runtimeWindow);
-
-					if (!initial)
-					{
-						logger.Info("Terminating application...");
-						shutdown.Invoke();
-					}
-				}
 			}
 		}
 
@@ -207,7 +243,6 @@ namespace SafeExamBrowser.Runtime
 			if (success)
 			{
 				logger.Info("### --- Session Terminated --- ###");
-				sessionRunning = false;
 			}
 			else
 			{
@@ -218,32 +253,34 @@ namespace SafeExamBrowser.Runtime
 
 		private void RegisterEvents()
 		{
+			runtimeHost.ClientConfigurationNeeded += RuntimeHost_ClientConfigurationNeeded;
 			runtimeHost.ReconfigurationRequested += RuntimeHost_ReconfigurationRequested;
 			runtimeHost.ShutdownRequested += RuntimeHost_ShutdownRequested;
 		}
 
 		private void DeregisterEvents()
 		{
+			runtimeHost.ClientConfigurationNeeded -= RuntimeHost_ClientConfigurationNeeded;
 			runtimeHost.ReconfigurationRequested -= RuntimeHost_ReconfigurationRequested;
 			runtimeHost.ShutdownRequested -= RuntimeHost_ShutdownRequested;
 		}
 
 		private void RegisterSessionEvents()
 		{
-			configuration.CurrentSession.ClientProcess.Terminated += ClientProcess_Terminated;
+			sessionContext.ClientProcess.Terminated += ClientProcess_Terminated;
-			configuration.CurrentSession.ClientProxy.ConnectionLost += Client_ConnectionLost;
+			sessionContext.ClientProxy.ConnectionLost += Client_ConnectionLost;
 		}
 
 		private void DeregisterSessionEvents()
 		{
-			if (configuration.CurrentSession.ClientProcess != null)
+			if (sessionContext.ClientProcess != null)
 			{
-				configuration.CurrentSession.ClientProcess.Terminated -= ClientProcess_Terminated;
+				sessionContext.ClientProcess.Terminated -= ClientProcess_Terminated;
 			}
 
-			if (configuration.CurrentSession.ClientProxy != null)
+			if (sessionContext.ClientProxy != null)
 			{
-				configuration.CurrentSession.ClientProxy.ConnectionLost -= Client_ConnectionLost;
+				sessionContext.ClientProxy.ConnectionLost -= Client_ConnectionLost;
 			}
 		}
 
@@ -261,7 +298,7 @@ namespace SafeExamBrowser.Runtime
 		{
 			logger.Error($"Client application has unexpectedly terminated with exit code {exitCode}!");
 
-			if (sessionRunning)
+			if (SessionIsRunning)
 			{
 				StopSession();
 			}
@@ -275,7 +312,7 @@ namespace SafeExamBrowser.Runtime
 		{
 			logger.Error("Lost connection to the client application!");
 
-			if (sessionRunning)
+			if (SessionIsRunning)
 			{
 				StopSession();
 			}
@@ -285,21 +322,31 @@ namespace SafeExamBrowser.Runtime
 			shutdown.Invoke();
 		}
 
+		private void RuntimeHost_ClientConfigurationNeeded(ClientConfigurationEventArgs args)
+		{
+			args.ClientConfiguration = new ClientConfiguration
+			{
+				AppConfig = sessionContext.Next.AppConfig,
+				SessionId = sessionContext.Next.Id,
+				Settings = sessionContext.Next.Settings
+			};
+		}
+
 		private void RuntimeHost_ReconfigurationRequested(ReconfigurationEventArgs args)
 		{
-			var mode = configuration.CurrentSettings.ConfigurationMode;
+			var mode = Session.Settings.ConfigurationMode;
 
 			if (mode == ConfigurationMode.ConfigureClient)
 			{
 				logger.Info($"Accepted request for reconfiguration with '{args.ConfigurationPath}'.");
-				configuration.ReconfigurationFilePath = args.ConfigurationPath;
+				sessionContext.ReconfigurationFilePath = args.ConfigurationPath;
 
 				StartSession();
 			}
 			else
 			{
 				logger.Info($"Denied request for reconfiguration with '{args.ConfigurationPath}' due to '{mode}' mode!");
-				configuration.CurrentSession.ClientProxy.InformReconfigurationDenied(args.ConfigurationPath);
+				sessionContext.ClientProxy.InformReconfigurationDenied(args.ConfigurationPath);
 			}
 		}
 
@@ -333,8 +380,8 @@ namespace SafeExamBrowser.Runtime
 
 		private void AskForPassword(PasswordRequiredEventArgs args)
 		{
-			var isStartup = configuration.CurrentSession == null;
+			var isStartup = !SessionIsRunning;
-			var isRunningOnDefaultDesktop = configuration.CurrentSettings?.KioskMode == KioskMode.DisableExplorerShell;
+			var isRunningOnDefaultDesktop = SessionIsRunning && Session.Settings.KioskMode == KioskMode.DisableExplorerShell;
 
 			if (isStartup || isRunningOnDefaultDesktop)
 			{
@@ -374,7 +421,7 @@ namespace SafeExamBrowser.Runtime
 
 			runtimeHost.PasswordReceived += responseEventHandler;
 
-			var communication = configuration.CurrentSession.ClientProxy.RequestPassword(args.Purpose, requestId);
+			var communication = sessionContext.ClientProxy.RequestPassword(args.Purpose, requestId);
 
 			if (communication.Success)
 			{
@@ -401,6 +448,9 @@ namespace SafeExamBrowser.Runtime
 			runtimeWindow?.UpdateStatus(status, true);
 		}
 
+		/// <summary>
+		/// TODO: Move to utility in core library and use in client controller!
+		/// </summary>
 		private void MapProgress(IProgressIndicator progressIndicator, ProgressChangedEventArgs args)
 		{
 			if (args.CurrentValue.HasValue)

SafeExamBrowser.Runtime/SafeExamBrowser.Runtime.csproj

@@ -94,6 +94,8 @@
     <Compile Include="Operations\KioskModeOperation.cs" />
     <Compile Include="Operations\KioskModeTerminationOperation.cs" />
     <Compile Include="Operations\ServiceOperation.cs" />
+    <Compile Include="Operations\SessionActivationOperation.cs" />
+    <Compile Include="Operations\SessionOperation.cs" />
     <Compile Include="Operations\SessionInitializationOperation.cs" />
     <Compile Include="Communication\ProxyFactory.cs" />
     <Compile Include="Communication\RuntimeHost.cs" />
@@ -112,6 +114,7 @@
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
     <Compile Include="RuntimeController.cs" />
+    <Compile Include="SessionContext.cs" />
     <EmbeddedResource Include="Properties\Resources.resx">
       <Generator>ResXFileCodeGenerator</Generator>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>

SafeExamBrowser.Runtime/SessionContext.cs

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2018 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.Contracts.Communication.Proxies;
+using SafeExamBrowser.Contracts.Configuration;
+using SafeExamBrowser.Contracts.WindowsApi;
+
+namespace SafeExamBrowser.Runtime
+{
+	/// <summary>
+	/// Holds all configuration and runtime data required for the session handling.
+	/// </summary>
+	internal class SessionContext
+	{
+		/// <summary>
+		/// The currently running client process.
+		/// </summary>
+		public IProcess ClientProcess { get; set; }
+
+		/// <summary>
+		/// The communication proxy for the currently running client process.
+		/// </summary>
+		public IClientProxy ClientProxy { get; set; }
+
+		/// <summary>
+		/// The configuration of the currently active session.
+		/// </summary>
+		public ISessionConfiguration Current { get; set; }
+
+		/// <summary>
+		/// The configuration of the next session to be activated.
+		/// </summary>
+		public ISessionConfiguration Next { get; set; }
+
+		/// <summary>
+		/// The path of the configuration file to be used for reconfiguration.
+		/// </summary>
+		public string ReconfigurationFilePath { get; set; }
+	}
+}