Restore SEBPatch

SafeExamBrowser.Communication.Contracts/Events/CommunicationEventHandler.cs

@@ -0,0 +1,41 @@
+/*
+ * 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.Threading.Tasks;
+
+namespace SafeExamBrowser.Communication.Contracts.Events
+{
+	/// <summary>
+	/// The default handler for communication events of an interlocutor.
+	/// </summary>
+	public delegate void CommunicationEventHandler();
+
+	/// <summary>
+	/// The handler with parameter for communication events of an interlocutor.
+	/// </summary>
+	public delegate void CommunicationEventHandler<T>(T args) where T : CommunicationEventArgs;
+
+	public static class CommunicationEventHandlerExtensions
+	{
+		/// <summary>
+		/// Executes the event handler asynchronously, i.e. on a separate thread.
+		/// </summary>
+		public static async Task InvokeAsync(this CommunicationEventHandler handler)
+		{
+			await Task.Run(() => handler?.Invoke());
+		}
+
+		/// <summary>
+		/// Executes the event handler asynchronously, i.e. on a separate thread.
+		/// </summary>
+		public static async Task InvokeAsync<T>(this CommunicationEventHandler<T> handler, T args) where T : CommunicationEventArgs
+		{
+			await Task.Run(() => handler?.Invoke(args));
+		}
+	}
+}