//
// NullGroupingProvider.cs
//
// Author:
//       Simon Lindgren <simon.n.lindgren@gmail.com>
//
// Copyright (c) 2013 Simon Lindgren
//
// 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.
using System;

namespace MonoDevelop.CodeIssues
{
	public class NullGroupingProvider: IGroupingProvider
	{
		static readonly Lazy<NullGroupingProvider> instance = new Lazy<NullGroupingProvider>();
		public static IGroupingProvider Instance
		{
			get {
				return instance.Value;
			}
		}

		#region IGroupingProvider implementation

		public IssueGroup GetIssueGroup (IssueGroup parent, IssueSummary issue)
		{
			return null;
		}

		public void Reset ()
		{
			// no-op
		}

		public IGroupingProvider Next {
			get {
				throw new InvalidOperationException ();
			}
			set {
				throw new InvalidOperationException ();
			}
		}
		
		event EventHandler<GroupingProviderEventArgs> nextChanged;
		
		event EventHandler<GroupingProviderEventArgs> IGroupingProvider.NextChanged
		{
			add {
				nextChanged += value;
			}
			remove {
				nextChanged -= value;
			}
		}

		public bool SupportsNext {
			get {
				return false;
			}
		}

		#endregion
	}
}