using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;

namespace Tango.Touch.Converters
{
    public class ScrollViewerThumbSizeConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            double scroll_viewer_height = (double)values[0];
            double content_height = (double)values[1];

            var viewableRatio = scroll_viewer_height / content_height;
            var result = scroll_viewer_height * viewableRatio;

            if (double.IsPositiveInfinity(result) || double.IsNegativeInfinity(result)) return 0.0;

            return result;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}