// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

#nullable disable

namespace System.Windows.Forms
{
    using System.ComponentModel;
    using System.Globalization;

    /// <summary>
    ///  ImageIndexConverter is a class that can be used to convert
    ///  image index values one data type to another.
    /// </summary>
    public class TreeViewImageKeyConverter : ImageKeyConverter
    {
        /// <summary>
        ///  Converts the given object to another type.  The most common types to convert
        ///  are to and from a string object.  The default implementation will make a call
        ///  to ToString on the object if the object is valid and if the destination
        ///  type is string.  If this cannot convert to the destination type, this will
        ///  throw a NotSupportedException.
        /// </summary>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            if (destinationType is null)
            {
                throw new ArgumentNullException(nameof(destinationType));
            }

            if (destinationType == typeof(string) && (value is null))
            {
                return SR.toStringDefault;
            }
            else
            {
                if (value is string strValue && (strValue.Length == 0))
                {
                    return SR.toStringDefault;
                }
            }

            return base.ConvertTo(context, culture, value, destinationType);
        }
    }
}
