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

namespace DTS.Common.Converters
{
    public class HeightConverter : MarkupExtension, IValueConverter
    {
        private static HeightConverter _instance;

        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return System.Convert.ToDouble(value) - System.Convert.ToInt32(parameter);
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }

        #endregion

        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return _instance ?? (_instance = new HeightConverter());
        }
    }
}