using System;
using System.ComponentModel;
using System.Xaml;
 
namespace System.Windows
{
    public class TemplateContentLoader : XamlDeferringLoader
    {
        public override object Load(XamlReader xamlReader, IServiceProvider serviceProvider)
        {
            if (serviceProvider == null)
            {
                throw new ArgumentNullException("serviceProvider");
            }
            else if (xamlReader == null)
            {
                throw new ArgumentNullException("xamlReader");
            }
 
            IXamlObjectWriterFactory factory = RequireService<IXamlObjectWriterFactory>(serviceProvider);
            return new TemplateContent(xamlReader, factory, serviceProvider);
        }
 
        private static T RequireService<T>(IServiceProvider provider) where T : class
        {
            T result = provider.GetService(typeof(T)) as T;
            if (result == null)
            {
                throw new InvalidOperationException(SR.Get(SRID.DeferringLoaderNoContext,typeof(TemplateContentLoader).Name, typeof(T).Name));
            }
            return result;
        }
 
        public override XamlReader Save(object value, IServiceProvider serviceProvider)
        {
            throw new NotSupportedException(SR.Get(SRID.DeferringLoaderNoSave, typeof(TemplateContentLoader).Name));
        }
    }
}