// --------------------------------------------------------------------------------------------------------------------
// <copyright file="ThicknessConverter.cs" company="OxyPlot">
//   Copyright (c) 2014 OxyPlot contributors
// </copyright>
// <summary>
//   Converts from <see cref="Thickness" /> to the maximum thicknesses.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

namespace OxyPlot.WP8
{
    using System;
    using System.Globalization;
    using System.Windows;
    using System.Windows.Data;

    /// <summary>
    /// Converts from <see cref="Thickness" /> to the maximum thicknesses.
    /// </summary>
    /// <remarks>This is used in the <see cref="TrackerControl" /> to convert BorderThickness properties to Path.StrokeThickness (double).
    /// The maximum thickness value is used.</remarks>
    public class ThicknessConverter : IValueConverter
    {
        /// <summary>
        /// Modifies the source data before passing it to the target for display in the UI.
        /// </summary>
        /// <param name="value">The source data being passed to the target.</param>
        /// <param name="targetType">The <see cref="T:System.Type" /> of data expected by the target dependency property.</param>
        /// <param name="parameter">An optional parameter to be used in the converter logic.</param>
        /// <param name="culture">The culture of the conversion.</param>
        /// <returns>The value to be passed to the target dependency property.</returns>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is Thickness)
            {
                var t = (Thickness)value;
                if (targetType == typeof(double))
                {
                    return Math.Max(Math.Max(t.Left, t.Right), Math.Max(t.Top, t.Bottom));
                }
            }

            return null;
        }

        /// <summary>
        /// Modifies the target data before passing it to the source object.  This method is called only in <see cref="F:System.Windows.Data.BindingMode.TwoWay" /> bindings.
        /// </summary>
        /// <param name="value">The target data being passed to the source.</param>
        /// <param name="targetType">The <see cref="T:System.Type" /> of data expected by the source object.</param>
        /// <param name="parameter">An optional parameter to be used in the converter logic.</param>
        /// <param name="culture">The culture of the conversion.</param>
        /// <returns>The value to be passed to the source object.</returns>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }
}