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using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Windows.Forms;

namespace Cyotek.Windows.Forms
{
  public class ZoomLevelCollectionConverter
    : TypeConverter
  {
    public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
    {
      return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
    }

    public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
    {
      return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
    }

    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
      string data;
      ZoomLevelCollection result;

      data = value as string;
      if (!string.IsNullOrEmpty(data))
      {
        char separator;
        string[] items;
        TypeConverter converter;

        if (culture == null)
          culture = CultureInfo.CurrentCulture;

        result = new ZoomLevelCollection();
        separator = culture.TextInfo.ListSeparator[0];
        items = data.Split(separator);
        converter = TypeDescriptor.GetConverter(typeof(int));

        foreach (string item in items)
          result.Add((int)converter.ConvertFromString(context, culture, item));
      }
      else
        result = null;

      return result;
    }

    public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
    {
      object result;

      if (destinationType == null)
        throw new ArgumentNullException("destinationType");

      if (value is ZoomLevelCollection)
      {
        if (destinationType == typeof(string))
        {
          ZoomLevelCollection collection;
          StringBuilder data;
          string separator;
          TypeConverter converter;

          collection = (ZoomLevelCollection)value;
          if (culture == null)
            culture = CultureInfo.CurrentCulture;
          separator = culture.TextInfo.ListSeparator + " ";
          converter = TypeDescriptor.GetConverter(typeof(int));
          data = new StringBuilder();

          foreach (int item in collection)
          {
            if (data.Length != 0)
              data.Append(separator);

            data.Append(converter.ConvertToString(context, culture, item));
          }

          result = data.ToString();
        }
        else if (destinationType == typeof(InstanceDescriptor))
        {
          ZoomLevelCollection collection;
          ConstructorInfo constructor;

          collection = (ZoomLevelCollection)value;
          constructor = typeof(ZoomLevelCollection).GetConstructor(new Type[] { typeof(IList<int>) });

          result = new InstanceDescriptor(constructor, new object[] { collection.ToArray() });
        }
        else
          result = null;
      }
      else
        result = null;

      if (result == null)
        result = base.ConvertTo(context, culture, value, destinationType);

      return result;
    }
  }
}