UserManager.cs :  » Business-Application » DC » DCSharp » Backend » Managers » C# / CSharp Open Source

/* 
 * Copyright (C) 2004-2005 Jonathan Bindel
 * Copyright (C) 2006-2007 Eskil Bylund
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

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

using DCSharp.Backend.Connections;
using DCSharp.Backend.Objects;

namespace DCSharp.Backend.Managers{
  public class UserManager : IEnumerable<Identity>
  {
    public event EventHandler<UserEventArgs> UserAdded;
    public event EventHandler<UserEventArgs> UserRemoved;
    public event EventHandler<UserEventArgs> UserChanged;

    private Dictionary<User, Identity> users;
    
    public UserManager()
    {
      users = new Dictionary<User, Identity>();
    }

    #region Properties
    
    public int Count
    {
      get { return users.Count; }
    }

    public Identity this[User user]
    {
      get
      {
        lock (users)
        {
          return users.ContainsKey(user) ? users[user] : null;
        }
      }
    }

    public object SyncRoot
    {
      get { return users; }
    }

    #endregion

    #region Methods

    public void Add(Identity identity)
    {
      if (identity == null)
      {
        throw new ArgumentNullException("identity");
      }
      lock (users)
      {
        if (!users.ContainsKey(identity.User))
        {
          users.Add(identity.User, identity);
          identity.User.AddIdentity(identity);
          
          OnUserAdded(identity);
        }
      }
    }

    public void Remove(Identity identity)
    {
      if (identity == null)
      {
        throw new ArgumentNullException("identity");
      }
      lock (users)
      {
        if (users.ContainsKey(identity.User))
        {
          users.Remove(identity.User);
          identity.User.RemoveIdentity(identity);
          
          OnUserRemoved(identity);
        }
      }
    }

    public void Clear()
    {
      lock (users)
      {
        User[] userArray = new User[users.Keys.Count];
        users.Keys.CopyTo(userArray, 0);
        
        foreach (User user in userArray)
        {
          Remove(this[user]);
        }
      }
    }

    public bool Contains(Identity user)
    {
      return users.ContainsValue(user);
    }

    public Identity Find(Predicate<Identity> match)
    {
      if (match == null)
      {
        throw new ArgumentNullException("match");
      }
      
      lock (users)
      {
        foreach (Identity user in users.Values)
        {
          if (match(user))
          {
            return user;
          }
        }
      }
      return null;
    }

    public void ForEach(Action<Identity> action)
    {
      if (action == null)
      {
        throw new ArgumentNullException("action");
      }
      
      lock (users)
      {
        foreach (Identity user in users.Values)
        {
          action(user);
        }
      }
    }

    public IEnumerator<Identity> GetEnumerator()
    {
      return users.Values.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }

    protected virtual void OnUserAdded(Identity user)
    {
      if (UserAdded != null)
      {
        UserAdded(this, new UserEventArgs(user));
      }
    }
    
    protected virtual void OnUserRemoved(Identity user)
    {
      if (UserRemoved != null)
      {
        UserRemoved(this, new UserEventArgs(user));
      }
    }

    protected void OnUserChanged(Identity user)
    {
      if (UserChanged != null)
      {
        UserChanged(this, new UserEventArgs(user));
      }
    }

    internal void EmitUserChanged(Identity user)
    {
      OnUserChanged(user);
    }

    #endregion
  }
}