content: /*
   *  ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
   *  Copyright (C) 2012 Kristian S. Stangeland
   *
   *  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
   */
  
  package com.comphenix.protocol.events;
  
  import com.comphenix.protocol.PacketType.Sender;
  
  /**
   * Used to set a packet filter.
   * 
   * @author Kristian
   */
  public enum ConnectionSide {
  	/**
  	 * Listen for server side packets that will invoke onPacketSending().
  	 */
  	SERVER_SIDE,
  	
  	/**
  	 * Listen for client side packets that will invoke onPacketReceiving().
  	 */
  	CLIENT_SIDE,
  	
  	/**
  	 * Listen for both client and server side packets.
  	 */
  	BOTH;
  	
  	public boolean isForClient() {
  		return this == CLIENT_SIDE || this == BOTH;
  	}
  	
  	public boolean isForServer() {
  		return this == SERVER_SIDE || this == BOTH;
  	}
  	
  	/**
  	 * Retrieve the sender of this connection side.
  	 * <p>
  	 * This is NULL for {@link #BOTH}.
  	 * @return The sender.
  	 */
  	public Sender getSender() {
  		if (this == SERVER_SIDE)
  			return Sender.SERVER;
  		else if (this == CLIENT_SIDE)
  			return Sender.CLIENT;
  		return null;
  	}
  	
  	/**
  	 * If both connection sides are present, return {@link #BOTH} - otherwise, return the one valud connection side.
  	 * <p>
  	 * NULL is not a valid connection side.
  	 * @param a - the first connection side.
  	 * @param b - the second connection side.
  	 * @return BOTH or the one valid side, or NULL.
  	 */
  	public static ConnectionSide add(ConnectionSide a, ConnectionSide b) {
  		if (a == null)
  			return b;
  		if (b == null)
  			return a;
  		
  		// Now merge them together
  		boolean client = a.isForClient() || b.isForClient();
  		boolean server = a.isForServer() || b.isForServer();
  		
  		if (client && server)
  			return BOTH;
  		else if (client)
  			return CLIENT_SIDE;
  		else
  			return SERVER_SIDE;
  	}
  }
  