source: other-projects/playing-in-the-street/summer-2013/trunk/Playing-in-the-Street-WPF/InverseBooleanConverter.cs@ 28897

// -----------------------------------------------------------------------
// <copyright file="InverseBooleanConverter.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
// -----------------------------------------------------------------------

namespace Microsoft.Samples.Kinect.WebserverBasics
{
    using System;
    using System.Windows.Data;

    /// <summary>
    /// Converts a boolean value to its inverse.
    /// </summary>
    [ValueConversion(typeof(bool), typeof(bool))]
    public class InverseBooleanConverter : IValueConverter
    {
        #region IValueConverter Members

        /// <summary>
        /// Converts a value.
        /// </summary>
        /// <param name="value">
        /// The value produced by the binding source.
        /// </param>
        /// <param name="targetType">
        /// The type of the binding target property.
        /// </param>
        /// <param name="parameter">
        /// The converter parameter to use.
        /// </param>
        /// <param name="culture">
        /// The culture to use in the converter.
        /// </param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (targetType != typeof(bool))
            {
                throw new InvalidOperationException("The target must be a boolean");
            }

            return !(bool)value;
        }

        /// <summary>
        /// Converts a value. 
        /// </summary>
        /// <param name="value">
        /// The value that is produced by the binding target.
        /// </param>
        /// <param name="targetType">
        /// The type to convert to.
        /// </param>
        /// <param name="parameter">
        /// The converter parameter to use.
        /// </param>
        /// <param name="culture">
        /// The culture to use in the converter.
        /// </param>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (targetType != typeof(bool))
            {
                throw new InvalidOperationException("The target must be a boolean");
            }

            return !(bool)value;
        }

        #endregion
    }
}