Represents the game world. Within each world holds an EntityList for each entity type it can contain along with functionality to register and unregister those entities from both view and internal encapsulation.

World.java

/*
 * Nital is an effort to provide a well documented, powerful, scalable, and robust 
 * RuneScape server framework delivered open-source to all users.
 *
 *  Copyright (C) 2011 Nital Software
 *
 *  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 3 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, see <http://www.gnu.org/licenses/>.
 */

package us.nital.world;

import us.nital.model.Player;
import us.nital.net.Session;
import us.nital.util.EntityList;
import us.nital.world.impl.GenericWorldLoader;

/**
 * Represents the game world. Within each world holds an
 * {@link EntityList} for each entity type it can contain
 * along with functionality to register and unregister those
 * entities from both view and internal encapsulation.
 * 
 * @author Thomas Nappo
 */
public final class World {

	/**
	 * This instance holds value of the singleton instance
	 * of the world class.
	 */
	private static final World SINGLETON = new World();

	/**
	 * Gets the singleton instance of the server.
	 * @return The one and only instance of the server.
	 */
	public static World getSingleton() {
		return SINGLETON;
	}

	/**
	 * This list encapsulates the players of the world, each assigned with
	 * their own index as the index inside the list.
	 */
	private final EntityList<Player> players = new EntityList<Player>(2000);

	/**
	 * Gets the world's {@link #players} list.
	 * @return This list encapsulates the players of the world, each assigned
	 * with their own index as the index inside the list.
	 */
	public EntityList<Player> getPlayers() {
		return players;
	}

	/**
	 * Loads the world for players by creating {@link Result} objects
	 * which contain attachments which specify information about the
	 * player's load result.
	 */
	private final WorldLoader worldLoader = new GenericWorldLoader();

	/**
	 * Appends a session to be registered.
	 * @param session The session to register.
	 * @return A result containing the <b>returnCode</b> and <b>player</b> or
	 * <code>null</code> if the registration failed.
	 */
	public Result register(Session session) {
		/*
		 * Should there be no available slot, we return back null
		 * to notify the failed registration.
		 */
		if (players.availableSlot() < 0) {
			return null;
		}

		/*
		 * Create a new player with an index equivalent to the next available
		 * slot of the player entity list.
		 */
		Player player = new Player(players.availableSlot(), session);

		/*
		 * If the world's list of players could not add the null
		 * is returned back to notify the failed registration.
		 */
		if (!players.add(player)) {
			return null;
		}

		/*
		 * Otherwise the world loader processes a new player created the
		 * available index.
		 */
		return worldLoader.process(player);
	}

}