Restore SEBPatch

SafeExamBrowser.Core/Operations/CommunicationHostOperation.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * 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.Communication.Contracts;
+using SafeExamBrowser.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.Logging.Contracts;
+
+namespace SafeExamBrowser.Core.Operations
+{
+	/// <summary>
+	/// An operation to handle the lifetime of an <see cref="ICommunicationHost"/>. The host is started during <see cref="Perform"/>,
+	/// stopped and restarted during <see cref="Repeat"/> (if not running) and stopped during <see cref="Revert"/>.
+	/// </summary>
+	public class CommunicationHostOperation : IRepeatableOperation
+	{
+		private ICommunicationHost host;
+		private ILogger logger;
+
+		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public event StatusChangedEventHandler StatusChanged;
+
+		public CommunicationHostOperation(ICommunicationHost host, ILogger logger)
+		{
+			this.host = host;
+			this.logger = logger;
+		}
+
+		public OperationResult Perform()
+		{
+			logger.Info("Starting communication host...");
+			StatusChanged?.Invoke(TextKey.OperationStatus_StartCommunicationHost);
+
+			host.Start();
+
+			return OperationResult.Success;
+		}
+
+		public OperationResult Repeat()
+		{
+			if (!host.IsRunning)
+			{
+				logger.Info("Restarting communication host...");
+				StatusChanged?.Invoke(TextKey.OperationStatus_RestartCommunicationHost);
+
+				host.Stop();
+				host.Start();
+			}
+
+			return OperationResult.Success;
+		}
+
+		public OperationResult Revert()
+		{
+			logger.Info("Stopping communication host...");
+			StatusChanged?.Invoke(TextKey.OperationStatus_StopCommunicationHost);
+
+			host.Stop();
+
+			return OperationResult.Success;
+		}
+	}
+}

SafeExamBrowser.Core/Operations/DelegateOperation.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * 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.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+
+namespace SafeExamBrowser.Core.Operations
+{
+	/// <summary>
+	/// A generic operation to allow for the (inline) definition of an operation via delegates. Useful if implementing a complete
+	/// <see cref="IOperation"/> would be an unnecessary overhead.
+	/// </summary>
+	public class DelegateOperation : IRepeatableOperation
+	{
+		private Action perform;
+		private Action repeat;
+		private Action revert;
+
+		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public event StatusChangedEventHandler StatusChanged { add { } remove { } }
+
+		public DelegateOperation(Action perform, Action repeat = null, Action revert = null)
+		{
+			this.perform = perform;
+			this.repeat = repeat;
+			this.revert = revert;
+		}
+
+		public OperationResult Perform()
+		{
+			perform?.Invoke();
+
+			return OperationResult.Success;
+		}
+
+		public OperationResult Repeat()
+		{
+			repeat?.Invoke();
+
+			return OperationResult.Success;
+		}
+
+		public OperationResult Revert()
+		{
+			revert?.Invoke();
+
+			return OperationResult.Success;
+		}
+	}
+}

SafeExamBrowser.Core/Operations/I18nOperation.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * 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.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+using SafeExamBrowser.I18n.Contracts;
+using SafeExamBrowser.Logging.Contracts;
+
+namespace SafeExamBrowser.Core.Operations
+{
+	/// <summary>
+	/// An operation to handle the initialization of an <see cref="IText"/> module with text data.
+	/// </summary>
+	public class I18nOperation : IOperation
+	{
+		private ILogger logger;
+		private IText text;
+
+		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
+		public event StatusChangedEventHandler StatusChanged { add { } remove { } }
+
+		public I18nOperation(ILogger logger, IText text)
+		{
+			this.logger = logger;
+			this.text = text;
+		}
+
+		public OperationResult Perform()
+		{
+			logger.Info($"Loading text data...");
+
+			text.Initialize();
+
+			return OperationResult.Success;
+		}
+
+		public OperationResult Revert()
+		{
+			return OperationResult.Success;
+		}
+	}
+}

SafeExamBrowser.Core/Operations/LazyInitializationOperation.cs

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+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ * 
+ * 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.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.Contracts.OperationModel.Events;
+
+namespace SafeExamBrowser.Core.Operations
+{
+	/// <summary>
+	/// A wrapper operation to allow for a lazy (just-in-time) instantiation of an operation, initialized on <see cref="Perform"/>.
+	/// Is useful when e.g. dependencies for a certain operation are not available during execution of the composition root, but rather
+	/// only after a preceding operation within an <see cref="IOperationSequence"/> has finished.
+	/// </summary>
+	public class LazyInitializationOperation : IOperation
+	{
+		private Func<IOperation> initialize;
+		private IOperation operation;
+
+		private event ActionRequiredEventHandler ActionRequiredImpl;
+		private event StatusChangedEventHandler StatusChangedImpl;
+
+		public event ActionRequiredEventHandler ActionRequired
+		{
+			add
+			{
+				ActionRequiredImpl += value;
+
+				if (operation != null)
+				{
+					operation.ActionRequired += value;
+				}
+			}
+			remove
+			{
+				ActionRequiredImpl -= value;
+
+				if (operation != null)
+				{
+					operation.ActionRequired -= value;
+				}
+			}
+		}
+
+		public event StatusChangedEventHandler StatusChanged
+		{
+			add
+			{
+				StatusChangedImpl += value;
+
+				if (operation != null)
+				{
+					operation.StatusChanged += value;
+				}
+			}
+			remove
+			{
+				StatusChangedImpl -= value;
+
+				if (operation != null)
+				{
+					operation.StatusChanged -= value;
+				}
+			}
+		}
+
+		public LazyInitializationOperation(Func<IOperation> initialize)
+		{
+			this.initialize = initialize;
+		}
+
+		public OperationResult Perform()
+		{
+			operation = initialize.Invoke();
+			operation.ActionRequired += ActionRequiredImpl;
+			operation.StatusChanged += StatusChangedImpl;
+
+			return operation.Perform();
+		}
+
+		public OperationResult Revert()
+		{
+			return operation.Revert();
+		}
+	}
+}