PropertyGrid/Avalonia.PropertyGrid/Converters/NumericFormatConverter.cs

using System;
using System.Globalization;
using Avalonia.Data.Converters;

namespace Avalonia.PropertyGrid.Controls;

/// <summary>
/// Converts PropertyType to appropriate numeric format string
/// </summary>
public sealed class NumericFormatConverter : IValueConverter
{
    /// <summary>
    /// Converts a Type to an appropriate numeric format string.
    /// </summary>
    /// <param name="value">The Type to convert.</param>
    /// <param name="targetType">The target type.</param>
    /// <param name="parameter">Optional parameter.</param>
    /// <param name="culture">Culture information.</param>
    /// <returns>A format string like "N2" for floating point or "N0" for integers.</returns>
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is Type type)
        {
            // Floating point types use decimal places
            if (type == typeof(float) || type == typeof(double) || type == typeof(decimal))
            {
                return "N2"; // 2 decimal places
            }

            // Integer types use no decimal places
            return "N0";
        }

        return "N0";
    }

    /// <summary>
    /// Not supported for this converter.
    /// </summary>
    /// <param name="value">The value to convert back.</param>
    /// <param name="targetType">The target type.</param>
    /// <param name="parameter">Optional parameter.</param>
    /// <param name="culture">Culture information.</param>
    /// <returns>Throws NotImplementedException.</returns>
    /// <exception cref="NotImplementedException">This converter does not support ConvertBack.</exception>
    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}