/*
 * Copyright 2019 faddenSoft
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
using System;
using System.Windows.Data;

namespace CommonWPF {
    /// <summary>
    /// A value inverter for negating a boolean value (value --> !value).
    /// 
    /// From <see href="https://stackoverflow.com/a/1039681/294248"/>.
    /// </summary>
    [ValueConversion(typeof(bool), typeof(bool))]
    public class InverseBooleanConverter : IValueConverter {
        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;
        }

        public object ConvertBack(object value, Type targetType, object parameter,
                System.Globalization.CultureInfo culture) {
            throw new NotSupportedException();
        }
    }
}