Newtonsoft.Json/Src/Newtonsoft.Json.Tests/TestObjects/IMyInterface.cs

#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Text;
#if NET20
using Newtonsoft.Json.Utilities.LinqBridge;
#else
using System.Linq;
#endif

namespace Newtonsoft.Json.Tests.TestObjects
{
#if !(NETFX_CORE || NET35 || NET20 || PORTABLE || DNXCORE50 || PORTABLE40)
    [TypeConverter(typeof(MyInterfaceConverter))]
    internal interface IMyInterface
    {
        string Name { get; }

        string PrintTest();
    }

    internal class MyInterfaceConverter : TypeConverter
    {
        private readonly List<IMyInterface> _writers = new List<IMyInterface>
            {
                new ConsoleWriter(),
                new TraceWriter()
            };

        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            return destinationType == typeof(string);
        }

        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            return sourceType == typeof(string);
        }

        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            if (value == null)
                return null;

            return (from w in _writers where w.Name == value.ToString() select w).FirstOrDefault();
        }

        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value,
            Type destinationType)
        {
            if (value == null)
                return null;
            return ((IMyInterface)value).Name;
        }
    }

    [TypeConverter(typeof(MyInterfaceConverter))]
    internal class ConsoleWriter : IMyInterface
    {
        public string Name
        {
            get { return "Console Writer"; }
        }

        public string PrintTest()
        {
            return "ConsoleWriter";
        }

        public override string ToString()
        {
            return Name;
        }
    }

    internal class TraceWriter : IMyInterface
    {
        public string Name
        {
            get { return "Trace Writer"; }
        }

        public override string ToString()
        {
            return Name;
        }

        public string PrintTest()
        {
            return "TraceWriter";
        }
    }

    internal class TypeConverterJsonConverter : JsonConverter
    {
        private TypeConverter GetConverter(Type type)
        {
            var converters = type.GetCustomAttributes(typeof(TypeConverterAttribute), true).Union(
                from t in type.GetInterfaces()
                from c in t.GetCustomAttributes(typeof(TypeConverterAttribute), true)
                select c).Distinct();

            return
                (from c in converters
                 let converter =
                     (TypeConverter)Activator.CreateInstance(Type.GetType(((TypeConverterAttribute)c).ConverterTypeName))
                 where converter.CanConvertFrom(typeof(string))
                       && converter.CanConvertTo(typeof(string))
                 select converter)
                    .FirstOrDefault();
        }


        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            var converter = GetConverter(value.GetType());
            var text = converter.ConvertToInvariantString(value);

            writer.WriteValue(text);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var converter = GetConverter(objectType);
            return converter.ConvertFromInvariantString(reader.Value.ToString());
        }

        public override bool CanConvert(Type objectType)
        {
            return GetConverter(objectType) != null;
        }
    }
#endif
}