#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2008 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Text;

namespace HeuristicLab.Core {
  public delegate void ChangedEventHandler(object sender, ChangedEventArgs e);

  public class ChangedEventArgs : EventArgs {
    private class ReferenceEqualityComparer : IEqualityComparer<object> {
      bool IEqualityComparer<object>.Equals(object x, object y) {
        return object.ReferenceEquals(x, y);
      }

      int IEqualityComparer<object>.GetHashCode(object obj) {
        if (obj == null) return 0;
        return obj.GetHashCode();
      }
    }

    private HashSet<object> changedObjects;

    public ChangedEventArgs() {
      changedObjects = new HashSet<object>(new ReferenceEqualityComparer());
    }

    public bool RegisterChangedObject(object obj) {
      return changedObjects.Add(obj);
    }
  }
}