wabbajack/Wabbajack/Converters/InverseBooleanConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;

namespace Wabbajack
{
    [ValueConversion(typeof(bool), typeof(bool))]
    public class InverseBooleanConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (targetType != typeof(bool))
                throw new InvalidOperationException($"The target must be of type bool");
            return !((bool)value);
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (targetType != typeof(bool))
                throw new InvalidOperationException($"The target must be of type bool");
            return !((bool)value);
        }
    }
}