SEBWIN-221: Implemented message box communication infrastructure and removed generic session start / stop error messages.

SafeExamBrowser.Client/ClientController.cs

@@ -160,6 +160,7 @@ namespace SafeExamBrowser.Client
 		private void RegisterEvents()
 		{
 			Browser.ConfigurationDownloadRequested += Browser_ConfigurationDownloadRequested;
+			ClientHost.MessageBoxRequested += ClientHost_MessageBoxRequested;
 			ClientHost.PasswordRequested += ClientHost_PasswordRequested;
 			ClientHost.ReconfigurationDenied += ClientHost_ReconfigurationDenied;
 			ClientHost.Shutdown += ClientHost_Shutdown;
@@ -173,6 +174,7 @@ namespace SafeExamBrowser.Client
 		private void DeregisterEvents()
 		{
 			Browser.ConfigurationDownloadRequested -= Browser_ConfigurationDownloadRequested;
+			ClientHost.MessageBoxRequested -= ClientHost_MessageBoxRequested;
 			ClientHost.PasswordRequested -= ClientHost_PasswordRequested;
 			ClientHost.ReconfigurationDenied -= ClientHost_ReconfigurationDenied;
 			ClientHost.Shutdown -= ClientHost_Shutdown;
@@ -259,6 +261,16 @@ namespace SafeExamBrowser.Client
 			}
 		}
 
+		private void ClientHost_MessageBoxRequested(MessageBoxRequestEventArgs args)
+		{
+			logger.Info($"Received message box request with id '{args.RequestId}'.");
+
+			var result = messageBox.Show(args.Message, args.Title, args.Action, args.Icon);
+
+			runtime.SubmitMessageBoxResult(args.RequestId, result);
+			logger.Info($"Message box request with id '{args.RequestId}' yielded result '{result}'.");
+		}
+
 		private void ClientHost_PasswordRequested(PasswordRequestEventArgs args)
 		{
 			var isAdmin = args.Purpose == PasswordRequestPurpose.Administrator;

SafeExamBrowser.Client/Communication/ClientHost.cs

@@ -23,6 +23,7 @@ namespace SafeExamBrowser.Client.Communication
 		public Guid StartupToken { private get; set; }
 		public bool IsConnected { get; private set; }
 
+		public event CommunicationEventHandler<MessageBoxRequestEventArgs> MessageBoxRequested;
 		public event CommunicationEventHandler<PasswordRequestEventArgs> PasswordRequested;
 		public event CommunicationEventHandler<ReconfigurationEventArgs> ReconfigurationDenied;
 		public event CommunicationEventHandler RuntimeDisconnected;
@@ -62,11 +63,14 @@ namespace SafeExamBrowser.Client.Communication
 		{
 			switch (message)
 			{
-				case PasswordRequestMessage p:
+				case MessageBoxRequestMessage m:
-					PasswordRequested?.InvokeAsync(new PasswordRequestEventArgs { Purpose = p.Purpose, RequestId = p.RequestId });
+					MessageBoxRequested?.InvokeAsync(new MessageBoxRequestEventArgs { Action = m.Action, Icon = m.Icon, Message = m.Message, RequestId = m.RequestId, Title = m.Title });
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
-				case ReconfigurationDeniedMessage r:
+				case PasswordRequestMessage m:
-					ReconfigurationDenied?.InvokeAsync(new ReconfigurationEventArgs { ConfigurationPath = r.FilePath });
+					PasswordRequested?.InvokeAsync(new PasswordRequestEventArgs { Purpose = m.Purpose, RequestId = m.RequestId });
+					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
+				case ReconfigurationDeniedMessage m:
+					ReconfigurationDenied?.InvokeAsync(new ReconfigurationEventArgs { ConfigurationPath = m.FilePath });
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
 			}
 

SafeExamBrowser.Communication/Proxies/ClientProxy.cs

@@ -10,6 +10,7 @@ using System;
 using SafeExamBrowser.Contracts.Communication.Data;
 using SafeExamBrowser.Contracts.Communication.Proxies;
 using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Contracts.UserInterface.MessageBox;
 
 namespace SafeExamBrowser.Communication.Proxies
 {
@@ -125,5 +126,31 @@ namespace SafeExamBrowser.Communication.Proxies
 				return new CommunicationResult(false);
 			}
 		}
+
+		public CommunicationResult ShowMessage(string message, string title, MessageBoxAction action, MessageBoxIcon icon, Guid requestId)
+		{
+			try
+			{
+				var response = Send(new MessageBoxRequestMessage(action, icon, message, requestId, title));
+				var success = IsAcknowledged(response);
+
+				if (success)
+				{
+					Logger.Debug("Client acknowledged message box request.");
+				}
+				else
+				{
+					Logger.Error($"Client did not acknowledge message box request! Received: {ToString(response)}.");
+				}
+
+				return new CommunicationResult(success);
+			}
+			catch (Exception e)
+			{
+				Logger.Error($"Failed to perform '{nameof(ShowMessage)}'", e);
+
+				return new CommunicationResult(false);
+			}
+		}
 	}
 }

SafeExamBrowser.Communication/Proxies/RuntimeProxy.cs

@@ -10,6 +10,7 @@ using System;
 using SafeExamBrowser.Contracts.Communication.Data;
 using SafeExamBrowser.Contracts.Communication.Proxies;
 using SafeExamBrowser.Contracts.Logging;
+using SafeExamBrowser.Contracts.UserInterface.MessageBox;
 
 namespace SafeExamBrowser.Communication.Proxies
 {
@@ -126,6 +127,32 @@ namespace SafeExamBrowser.Communication.Proxies
 			}
 		}
 
+		public CommunicationResult SubmitMessageBoxResult(Guid requestId, MessageBoxResult result)
+		{
+			try
+			{
+				var response = Send(new MessageBoxReplyMessage(requestId, result));
+				var acknowledged = IsAcknowledged(response);
+
+				if (acknowledged)
+				{
+					Logger.Debug("Runtime acknowledged message box result transmission.");
+				}
+				else
+				{
+					Logger.Error($"Runtime did not acknowledge message box result transmission! Response: {ToString(response)}.");
+				}
+
+				return new CommunicationResult(acknowledged);
+			}
+			catch (Exception e)
+			{
+				Logger.Error($"Failed to perform '{nameof(SubmitMessageBoxResult)}'", e);
+
+				return new CommunicationResult(false);
+			}
+		}
+
 		public CommunicationResult SubmitPassword(Guid requestId, bool success, string password = null)
 		{
 			try

SafeExamBrowser.Contracts/Communication/Data/MessageBoxReplyMessage.cs

@@ -0,0 +1,36 @@
+/*
+ * 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.UserInterface.MessageBox;
+
+namespace SafeExamBrowser.Contracts.Communication.Data
+{
+	/// <summary>
+	/// The reply to a <see cref="MessageBoxRequestMessage"/>.
+	/// </summary>
+	[Serializable]
+	public class MessageBoxReplyMessage : Message
+	{
+		/// <summary>
+		/// Identifies the message box request.
+		/// </summary>
+		public Guid RequestId { get; private set; }
+
+		/// <summary>
+		/// The result of the interaction.
+		/// </summary>
+		public MessageBoxResult Result { get; private set; }
+
+		public MessageBoxReplyMessage(Guid requestId, MessageBoxResult result)
+		{
+			RequestId = requestId;
+			Result = result;
+		}
+	}
+}

SafeExamBrowser.Contracts/Communication/Data/MessageBoxRequestMessage.cs

@@ -0,0 +1,54 @@
+/*
+ * 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.UserInterface.MessageBox;
+
+namespace SafeExamBrowser.Contracts.Communication.Data
+{
+	/// <summary>
+	/// This message is transmitted to the client to request a message box input by the user.
+	/// </summary>
+	[Serializable]
+	public class MessageBoxRequestMessage : Message
+	{
+		/// <summary>
+		/// The action to be displayed.
+		/// </summary>
+		public MessageBoxAction Action { get; private set; }
+
+		/// <summary>
+		/// The icon to be displayed.
+		/// </summary>
+		public MessageBoxIcon Icon { get; private set; }
+
+		/// <summary>
+		/// The message to be displayed.
+		/// </summary>
+		public string Message { get; private set; }
+
+		/// <summary>
+		/// Identifies the message box request.
+		/// </summary>
+		public Guid RequestId { get; private set; }
+
+		/// <summary>
+		/// The title to be displayed.
+		/// </summary>
+		public string Title { get; private set; }
+
+		public MessageBoxRequestMessage(MessageBoxAction action, MessageBoxIcon icon, string message, Guid requestId, string title)
+		{
+			Action = action;
+			Icon = icon;
+			Message = message;
+			RequestId = requestId;
+			Title = title;
+		}
+	}
+}

SafeExamBrowser.Contracts/Communication/Events/MessageBoxReplyEventArgs.cs

@@ -0,0 +1,29 @@
+/*
+ * 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.UserInterface.MessageBox;
+
+namespace SafeExamBrowser.Contracts.Communication.Events
+{
+	/// <summary>
+	/// The event arguments used for the message box reply event fired by the <see cref="Hosts.IRuntimeHost"/>.
+	/// </summary>
+	public class MessageBoxReplyEventArgs : CommunicationEventArgs
+	{
+		/// <summary>
+		/// Identifies the message box request.
+		/// </summary>
+		public Guid RequestId { get; set; }
+
+		/// <summary>
+		/// The result of the interaction.
+		/// </summary>
+		public MessageBoxResult Result { get; set; }
+	}
+}

SafeExamBrowser.Contracts/Communication/Events/MessageBoxRequestEventArgs.cs

@@ -0,0 +1,44 @@
+/*
+ * 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.UserInterface.MessageBox;
+
+namespace SafeExamBrowser.Contracts.Communication.Events
+{
+	/// <summary>
+	/// The event arguments used for the message box request event fired by the <see cref="Hosts.IClientHost"/>.
+	/// </summary>
+	public class MessageBoxRequestEventArgs : CommunicationEventArgs
+	{
+		/// <summary>
+		/// The action to be displayed.
+		/// </summary>
+		public MessageBoxAction Action { get; set; }
+
+		/// <summary>
+		/// The icon to be displayed.
+		/// </summary>
+		public MessageBoxIcon Icon { get; set; }
+
+		/// <summary>
+		/// The message to be displayed.
+		/// </summary>
+		public string Message { get; set; }
+
+		/// <summary>
+		/// Identifies the message box request.
+		/// </summary>
+		public Guid RequestId { get; set; }
+
+		/// <summary>
+		/// The title to be displayed.
+		/// </summary>
+		public string Title { get; set; }
+	}
+}

SafeExamBrowser.Contracts/Communication/Hosts/IClientHost.cs

@@ -26,6 +26,11 @@ namespace SafeExamBrowser.Contracts.Communication.Hosts
 		/// </summary>
 		Guid StartupToken { set; }
 
+		/// <summary>
+		/// Event fired when the runtime requests a message box input from the user.
+		/// </summary>
+		event CommunicationEventHandler<MessageBoxRequestEventArgs> MessageBoxRequested;
+
 		/// <summary>
 		/// Event fired when the runtime requests a password input from the user.
 		/// </summary>

SafeExamBrowser.Contracts/Communication/Hosts/IRuntimeHost.cs

@@ -41,6 +41,11 @@ namespace SafeExamBrowser.Contracts.Communication.Hosts
 		/// </summary>
 		event CommunicationEventHandler<ClientConfigurationEventArgs> ClientConfigurationNeeded;
 
+		/// <summary>
+		/// Event fired when the client submitted a message box result chosen by the user.
+		/// </summary>
+		event CommunicationEventHandler<MessageBoxReplyEventArgs> MessageBoxReplyReceived;
+
 		/// <summary>
 		/// Event fired when the client submitted a password entered by the user.
 		/// </summary>

SafeExamBrowser.Contracts/Communication/ICommunication.cs

@@ -20,6 +20,8 @@ namespace SafeExamBrowser.Contracts.Communication
 	[ServiceKnownType(typeof(AuthenticationResponse))]
 	[ServiceKnownType(typeof(ClientConfiguration))]
 	[ServiceKnownType(typeof(ConfigurationResponse))]
+	[ServiceKnownType(typeof(MessageBoxReplyMessage))]
+	[ServiceKnownType(typeof(MessageBoxRequestMessage))]
 	[ServiceKnownType(typeof(PasswordReplyMessage))]
 	[ServiceKnownType(typeof(PasswordRequestMessage))]
 	[ServiceKnownType(typeof(ReconfigurationMessage))]

SafeExamBrowser.Contracts/Communication/Proxies/IClientProxy.cs

@@ -8,6 +8,7 @@
 
 using System;
 using SafeExamBrowser.Contracts.Communication.Data;
+using SafeExamBrowser.Contracts.UserInterface.MessageBox;
 
 namespace SafeExamBrowser.Contracts.Communication.Proxies
 {
@@ -35,5 +36,10 @@ namespace SafeExamBrowser.Contracts.Communication.Proxies
 		/// Requests the client to render a password dialog and subsequently return the interaction result as separate message.
 		/// </summary>
 		CommunicationResult RequestPassword(PasswordRequestPurpose purpose, Guid requestId);
+
+		/// <summary>
+		/// Requests the client to render a message box and subsequently return the interaction result as separate message.
+		/// </summary>
+		CommunicationResult ShowMessage(string message, string title, MessageBoxAction action, MessageBoxIcon icon, Guid requestId);
 	}
 }

SafeExamBrowser.Contracts/Communication/Proxies/IRuntimeProxy.cs

@@ -8,6 +8,7 @@
 
 using System;
 using SafeExamBrowser.Contracts.Communication.Data;
+using SafeExamBrowser.Contracts.UserInterface.MessageBox;
 
 namespace SafeExamBrowser.Contracts.Communication.Proxies
 {
@@ -36,6 +37,11 @@ namespace SafeExamBrowser.Contracts.Communication.Proxies
 		/// </summary>
 		CommunicationResult RequestReconfiguration(string filePath);
 
+		/// <summary>
+		/// Submits the result of a message box input previously requested by the runtime.
+		/// </summary>
+		CommunicationResult SubmitMessageBoxResult(Guid requestId, MessageBoxResult result);
+
 		/// <summary>
 		/// Submits the result of a password input previously requested by the runtime. If the procedure was aborted by the user,
 		/// the password parameter will be <c>null</c>!

SafeExamBrowser.Contracts/I18n/TextKey.cs

@@ -38,10 +38,6 @@ namespace SafeExamBrowser.Contracts.I18n
 		MessageBox_ReconfigurationErrorTitle,
 		MessageBox_ReconfigurationQuestion,
 		MessageBox_ReconfigurationQuestionTitle,
-		MessageBox_SessionStartError,
-		MessageBox_SessionStartErrorTitle,
-		MessageBox_SessionStopError,
-		MessageBox_SessionStopErrorTitle,
 		MessageBox_ShutdownError,
 		MessageBox_ShutdownErrorTitle,
 		MessageBox_SingleInstance,

SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj

@@ -52,7 +52,11 @@
     <Reference Include="System.ServiceModel" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Communication\Data\MessageBoxReplyMessage.cs" />
+    <Compile Include="Communication\Data\MessageBoxRequestMessage.cs" />
     <Compile Include="Communication\Events\ClientConfigurationEventArgs.cs" />
+    <Compile Include="Communication\Events\MessageBoxReplyEventArgs.cs" />
+    <Compile Include="Communication\Events\MessageBoxRequestEventArgs.cs" />
     <Compile Include="Configuration\Cryptography\EncryptionParameters.cs" />
     <Compile Include="Configuration\Cryptography\PasswordParameters.cs" />
     <Compile Include="Configuration\Cryptography\PublicKeyHashParameters.cs" />

SafeExamBrowser.I18n/Text.xml

@@ -72,18 +72,6 @@
   <Entry key="MessageBox_ReconfigurationQuestionTitle">
     Configuration Detected
   </Entry>
-  <Entry key="MessageBox_SessionStartError">
-    The application failed to start a new session. Please consult the application log for more information...
-  </Entry>
-  <Entry key="MessageBox_SessionStartErrorTitle">
-    Session Start Error
-  </Entry>
-  <Entry key="MessageBox_SessionStopError">
-    The application failed to properly stop the running session. Please consult the application log for more information...
-  </Entry>
-  <Entry key="MessageBox_SessionStopErrorTitle">
-    Session Stop Error
-  </Entry>
   <Entry key="MessageBox_ShutdownError">
     An unexpected error occurred during the shutdown procedure! Please consult the application log for more information...
   </Entry>

SafeExamBrowser.Runtime/Communication/RuntimeHost.cs

@@ -23,6 +23,7 @@ namespace SafeExamBrowser.Runtime.Communication
 		public event CommunicationEventHandler ClientDisconnected;
 		public event CommunicationEventHandler ClientReady;
 		public event CommunicationEventHandler<ClientConfigurationEventArgs> ClientConfigurationNeeded;
+		public event CommunicationEventHandler<MessageBoxReplyEventArgs> MessageBoxReplyReceived;
 		public event CommunicationEventHandler<PasswordReplyEventArgs> PasswordReceived;
 		public event CommunicationEventHandler<ReconfigurationEventArgs> ReconfigurationRequested;
 		public event CommunicationEventHandler ShutdownRequested;
@@ -53,11 +54,14 @@ namespace SafeExamBrowser.Runtime.Communication
 		{
 			switch (message)
 			{
-				case PasswordReplyMessage r:
+				case MessageBoxReplyMessage m:
-					PasswordReceived?.InvokeAsync(new PasswordReplyEventArgs { Password = r.Password, RequestId = r.RequestId, Success = r.Success });
+					MessageBoxReplyReceived?.InvokeAsync(new MessageBoxReplyEventArgs { RequestId = m.RequestId, Result = m.Result });
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
-				case ReconfigurationMessage r:
+				case PasswordReplyMessage m:
-					ReconfigurationRequested?.InvokeAsync(new ReconfigurationEventArgs { ConfigurationPath = r.ConfigurationPath });
+					PasswordReceived?.InvokeAsync(new PasswordReplyEventArgs { Password = m.Password, RequestId = m.RequestId, Success = m.Success });
+					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
+				case ReconfigurationMessage m:
+					ReconfigurationRequested?.InvokeAsync(new ReconfigurationEventArgs { ConfigurationPath = m.ConfigurationPath });
 					return new SimpleResponse(SimpleResponsePurport.Acknowledged);
 			}
 

SafeExamBrowser.Runtime/Operations/ConfigurationOperation.cs

@@ -273,6 +273,7 @@ namespace SafeExamBrowser.Runtime.Operations
 			else
 			{
 				logger.Info("Authentication has failed!");
+				ActionRequired?.Invoke(new InvalidPasswordMessageArgs());
 
 				return OperationResult.Failed;
 			}

SafeExamBrowser.Runtime/RuntimeController.cs

@@ -207,9 +207,7 @@ namespace SafeExamBrowser.Runtime
 			{
 				StopSession();
 
-				messageBox.Show(TextKey.MessageBox_SessionStartError, TextKey.MessageBox_SessionStartErrorTitle, icon: MessageBoxIcon.Error, parent: runtimeWindow);
 				logger.Info("Terminating application...");
-
 				shutdown.Invoke();
 			}
 		}
@@ -247,7 +245,6 @@ namespace SafeExamBrowser.Runtime
 			else
 			{
 				logger.Info("### --- Session Stop Failed --- ###");
-				messageBox.Show(TextKey.MessageBox_SessionStopError, TextKey.MessageBox_SessionStopErrorTitle, icon: MessageBoxIcon.Error, parent: runtimeWindow);
 			}
 		}
 
@@ -419,10 +416,40 @@ namespace SafeExamBrowser.Runtime
 			}
 			else
 			{
-				// TODO
+				ShowMessageBoxViaClient(message, title, MessageBoxAction.Confirm, args.Icon);
 			}
 		}
 
+		private MessageBoxResult ShowMessageBoxViaClient(string message, string title, MessageBoxAction confirm, MessageBoxIcon icon)
+		{
+			var requestId = Guid.NewGuid();
+			var result = MessageBoxResult.None;
+			var response = default(MessageBoxReplyEventArgs);
+			var responseEvent = new AutoResetEvent(false);
+			var responseEventHandler = new CommunicationEventHandler<MessageBoxReplyEventArgs>((args) =>
+			{
+				if (args.RequestId == requestId)
+				{
+					response = args;
+					responseEvent.Set();
+				}
+			});
+
+			runtimeHost.MessageBoxReplyReceived += responseEventHandler;
+
+			var communication = sessionContext.ClientProxy.ShowMessage(message, title, MessageBoxAction.Confirm, icon, requestId);
+
+			if (communication.Success)
+			{
+				responseEvent.WaitOne();
+				result = response.Result;
+			}
+
+			runtimeHost.MessageBoxReplyReceived -= responseEventHandler;
+
+			return result;
+		}
+
 		private void TryGetPasswordViaDialog(PasswordRequiredEventArgs args)
 		{
 			var isAdmin = args.Purpose == PasswordRequestPurpose.Administrator;