DoubleCompareConverter

DoubleCompareConverter.cs

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

namespace Converter
{
    public class DoubleCompareConverter : IValueConverter
    {

        private static readonly SizeConverter SizeConverter = new SizeConverter();

        public static readonly DoubleCompareConverter LessThen = new DoubleCompareConverter("<");
        public static readonly DoubleCompareConverter GreaterThen = new DoubleCompareConverter(">");
        public static readonly DoubleCompareConverter LessThenOrEqual = new DoubleCompareConverter("<=");
        public static readonly DoubleCompareConverter GreaterThenOrEqual = new DoubleCompareConverter(">=");
        public static readonly DoubleCompareConverter Equal = new DoubleCompareConverter("==");
        public static readonly DoubleCompareConverter NotEqual = new DoubleCompareConverter("!=");
        public static readonly DoubleCompareConverter Between = new DoubleCompareConverter("{min,max}");

        private readonly string _operator;

        private DoubleCompareConverter(string @operator)
        {
            _operator = @operator;
        }

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var doubleValue = (double)System.Convert.ChangeType(value, TypeCode.Double);
            switch (_operator)
            {
                case "{min,max}":
                {
                    var range = (Size)SizeConverter.ConvertFrom(parameter);
                    return doubleValue >= range.Width && doubleValue < range.Height;
                }
            }
            var doubleParameter = (double)System.Convert.ChangeType(parameter, TypeCode.Double);
            switch (_operator)
            {
                case "<": return doubleValue < doubleParameter;
                case "<=": return doubleValue <= doubleParameter;
                case ">": return doubleValue > doubleParameter;
                case ">=": return doubleValue >= doubleParameter;
                case "==": return doubleValue == doubleParameter;
                case "!=": return doubleValue != doubleParameter;
                default: throw new NotSupportedException($"Operator '{_operator}' is not supported in {nameof(DoubleCompareConverter)}.");
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotSupportedException($"ConvertBack is not supported in {nameof(DoubleCompareConverter)}.");
        }
    }
}