Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="AppDomainExtensions.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   <see cref="AppDomain" /> extensions.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.Reflection;

#if SILVERLIGHT
using System.Windows;
using System.Windows.Resources;
#endif

namespace Catel.Reflection
{
	/// <summary>
	/// <see cref="AppDomain"/> extensions.
	/// </summary>
	public static class AppDomainExtensions
	{
		/// <summary>
		/// Gets a list of all types inside the <see cref="AppDomain"/> that have the <paramref name="baseType"/> as base class.
        /// <para />
		/// If the specified base type is an interface, the types that are returned are types that implement the interface.
		/// If the specified base type is a class, the types that have the type as base class are returned.
		/// </summary>
		/// <param name="appDomain">The app domain.</param>
		/// <param name="baseType">Type of the base class.</param>
		/// <returns>List of types found in the <see cref="AppDomain"/>.</returns>
		public static Type[] GetTypes(this AppDomain appDomain, Type baseType)
		{
			if (appDomain == null)
			{
				throw new ArgumentNullException("appDomain");
			}

			if (baseType == null)
			{
				throw new ArgumentNullException("baseType");
			}

			List<Type> types = new List<Type>();

			List<Assembly> assemblies = AssemblyHelper.GetLoadedAssemblies(appDomain);
			foreach (Assembly assembly in assemblies)
			{
				Type[] assemblyTypes = assembly.GetTypes();
				foreach (Type assemblyType in assemblyTypes)
				{
					if (baseType.IsInterface)
					{
						if (assemblyType.GetInterface(baseType.Name, false) != null)
						{
							types.Add(assemblyType);
						}
					}
					else if (baseType.IsClass)
					{
						if (assemblyType.IsSubclassOf(baseType))
						{
							types.Add(assemblyType);
						}
					}
				}
			}

			return types.ToArray();
		}

		/// <summary>
		/// Gets a list of all types inside the <see cref="AppDomain"/> that have the <typeparamref name="TBaseType"/> as base class.
		/// </summary>
		/// <typeparam name="TBaseType">The type of the base class.</typeparam>
		/// <param name="appDomain">The app domain.</param>
		/// <returns>
		/// List of types found in the <see cref="AppDomain"/>.
		/// </returns>
		public static Type[] GetTypes<TBaseType>(this AppDomain appDomain)
		{
			return GetTypes(appDomain, typeof(TBaseType));
		}
	}
}