Capacity.java

/*
 * Copyright (c) 2007 Tom Parker <thpr@users.sourceforge.net>
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 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 Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
package pcgen.cdom.helper;

import java.math.BigDecimal;

/**
 * A Capacity represents the carrying capacity of a container (this is a
 * specific feature of certain types of Equipment)
 */
public class Capacity
{

	/**
	 * The constants that represents the special case of unlimited carrying
	 * capacity.
	 */
	public static final BigDecimal UNLIMITED = new BigDecimal(-1);

	/*
	 * CONSIDER Need to flesh out how this works; depends on how Capacity
	 * interacts with the core... - Tom Parker 3/1/07
	 */
	/**
	 * The special case that represents unlimited capacity for any object.
	 */
	public static final Capacity ANY = new Capacity(null, UNLIMITED);

	/**
	 * The type of objects that this Capacity represents
	 */
	private final String type;

	/**
	 * The value indicating the upper limit of the number of objects (of the
	 * type that this Capacity represents) that this Capacity allows.
	 */
	private final BigDecimal limit;

	/**
	 * Constructs a new Capacity for the given type with the given upper limit
	 * on capacity.
	 * 
	 * @param capacityType
	 *            The type of objects that this Capacity represents
	 * @param capacityLimit
	 *            The value indicating the upper limit of the number of objects
	 *            (of the given type) that this Capacity allows
	 */
	public Capacity(String capacityType, BigDecimal capacityLimit)
	{
		type = capacityType;
		limit = capacityLimit;
	}

	/**
	 * Returns the value indicating the upper limit of the number of objects (of
	 * the type that this Capacity represents) that this Capacity allows.
	 * 
	 * @return The value indicating the upper limit of the number of objects (of
	 *         the type that this Capacity represents) that this Capacity
	 *         allows.
	 */
	public BigDecimal getCapacity()
	{
		return limit;
	}

	/**
	 * Returns the type of objects that this Capacity represents.
	 * 
	 * @return The type of objects that this Capacity represents
	 */
	public String getType()
	{
		return type;
	}

	/**
	 * Provides a convenience method for producing a "Total" capacity object for
	 * a container.
	 * 
	 * @param capacity
	 *            The total capacity limit used to construct the returned
	 *            Capacity.
	 * @return A new Capacity object for a container with the given total
	 *         capacity limit.
	 */
	public static Capacity getTotalCapacity(BigDecimal capacity)
	{
		return new Capacity(null, capacity);
	}

	/**
	 * Returns a String representation of this Capacity.
	 * 
	 * @return A String representation of this Capacity.
	 * @see java.lang.Object#toString()
	 */
	@Override
	public String toString()
	{
		StringBuilder sb = new StringBuilder(50);
		sb.append("Capacity: ");
		sb.append(type == null ? "Total" : type);
		sb.append('=');
		sb.append(UNLIMITED.equals(limit) ? "UNLIMITED" : limit);
		return sb.toString();
	}

	/**
	 * Returns a consistent-with-equals hashCode for this Capacity
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode()
	{
		return type == null ? 0 : type.hashCode() ^ limit.hashCode();
	}

	/**
	 * Returns true if the given object is a Capacity with identical underlying
	 * type and capacity limit.
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj)
	{
		if (obj instanceof Capacity)
		{
			Capacity other = (Capacity) obj;
			if (type == null)
			{
				if (other.type != null)
				{
					return false;
				}
			}
			else
			{
				if (!type.equals(other.type))
				{
					return false;
				}
			}
			return limit.equals(other.limit);
		}
		return false;
	}
}