Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="AreEqualMultiValueConverter.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   Converts a comparison of 2 bindings to a boolean whether the
//   objects are equal or not.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Windows.Data;

namespace Catel.Windows.Data.Converters
{
	/// <summary>
	/// Converts a comparison of 2 bindings to a boolean whether the 
	/// objects are equal or not.
	/// </summary>
#if !SILVERLIGHT
	[ValueConversion(typeof(object), typeof(object))]
#endif
	public class AreEqualMultiValueConverter : IMultiValueConverter
	{
		/// <summary>
		/// Converts the comparison of 2 values to a boolean.
		/// </summary>
		/// <param name="values">Values to convert. Only 2 values are supported.</param>
		/// <param name="targetType">Not supported.</param>
		/// <param name="parameter">Not supported.</param>
		/// <param name="culture">Not supported.</param>
		/// <returns>True if the values are equal, otherwise false.</returns>
		public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
		{
			// Check input
			if (values.Length != 2)
			{
			    return false;
			}

			// Get values
			object value1 = values[0];
			object value2 = values[1];

            // Check if both values are null
            if ((value1 == null) && (value2 == null))
            {
                return true;
            }

			// Check if one of the values is null
			if ((value1 == null) || (value2 == null))
			{
			    return false;
			}

			// Compare objects
			return value1.Equals(value2);
		}

		/// <summary>
		/// Not supported.
		/// </summary>
		/// <param name="value">Not supported.</param>
		/// <param name="targetTypes">Not supported.</param>
		/// <param name="parameter">Not supported.</param>
		/// <param name="culture">Not supported.</param>
		/// <returns>Not supported.</returns>
		public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
		{
		    // Not supported (and IMultiValueConverter must return null if no conversion is supported)
		    return null;
		}
	}
}