Avalonia/samples/ControlCatalog/Converter/FlexDemoNumberToThicknessConverter.cs

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

namespace ControlCatalog.Converter
{
    internal sealed class FlexDemoNumberToThicknessConverter : IValueConverter
    {
        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
        {
            if (value is int x && targetType.IsAssignableFrom(typeof(Thickness)))
            {
                var y = 16 + 2 * ((x * 5) % 9);
                return new Thickness(2 * y, y);
            }

            throw new NotSupportedException();
        }

        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) =>
            throw new NotSupportedException();
    }
}