Catel - Part 4 of n: Unit testing with Catel

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="BooleanToOppositeBooleanConverter.cs" company="Catel development team">
//   Copyright (c) 2008 - 2011 Catel development team. All rights reserved.
// </copyright>
// <summary>
//   Convert a value to it's inverted value.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

using System;
using System.Windows.Data;

namespace Catel.Windows.Data.Converters
{
    /// <summary>
    /// Convert a value to it's inverted value.
    /// </summary>
    /// <remarks>Currently only values of type bool are accepted.</remarks>
#if !SILVERLIGHT
    [ValueConversion(typeof(bool), typeof(bool))]
#endif
    public class BooleanToOppositeBooleanConverter : IValueConverter
    {
        /// <summary>
        /// Converts value to the inverted value.
        /// </summary>
        /// <param name="value">A value, currently only bool supported.</param>
        /// <param name="targetType">Currently only bool supported.</param>
        /// <param name="parameter">Not in use.</param>
        /// <param name="culture">Not in use.</param>
        /// <returns>The inverted value.</returns>
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            bool? result = value as bool?;
            if (result.HasValue)
            {
                result = !result.Value;
            }

            return result;
        }

        /// <summary>
        /// Converts value back, simply inverts again.
        /// </summary>
        /// <param name="value">A value, currently only bool supported.</param>
        /// <param name="targetType">Currently only bool supported.</param>
        /// <param name="parameter">Not in use.</param>
        /// <param name="culture">Not in use.</param>
        /// <returns>The inverted value.</returns>
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            bool? result = value as bool?;
            if (result.HasValue)
            {
                result = !result.Value;
            }

            return result;
        }
    }
}