/* ===========================================================

 * JFreeChart : a free chart library for the Java(tm) platform

 * ===========================================================

 *

 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.

 *

 * Project Info:  http://www.jfree.org/jfreechart/index.html

 *

 * This library 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 library 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., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 *

 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 

 * in the United States and other countries.]

 *

 * ------------------

 * HistogramType.java

 * ------------------

 * (C) Copyright 2004, by Object Refinery Limited and Contributors.

 *

 * Original Author:  David Gilbert (for Object Refinery Limited);

 * Contributor(s):   -;

 *

 * $Id: HistogramType.java,v 1.1 2004/08/31 15:32:24 mungady Exp $

 *

 * Changes

 * -------

 * 05-Mar-2004 : Version 1 (DG);

 * 

 */



package org.jfree.data.statistics;



import java.io.ObjectStreamException;

import java.io.Serializable;

    

/**

 * A class for creating constants to represent the histogram type.  See Bloch's enum tip in

 * 'Effective Java'

 */

public class HistogramType implements Serializable { 

        

    /** Frequency histogram. */

    public static final HistogramType FREQUENCY = new HistogramType("FREQUENCY");

    

    /** Relative frequency. */

    public static final HistogramType RELATIVE_FREQUENCY = new HistogramType("RELATIVE_FREQUENCY");

    

    /** Scale area to one. */

    public static final HistogramType SCALE_AREA_TO_1 = new HistogramType("SCALE_AREA_TO_1");



    /** The type name. */

    private String name;

        

    /** 

     * Creates a new type.

     * 

     * @param name  the name.

     */

    private HistogramType(final String name) {

        this.name = name;

    } 



    /**

     * Returns a string representing the object.

     *

     * @return the string.

     */

    public String toString() {

        return this.name;

    }



    /**

     * Tests this type for equality with an arbitrary object.

     *

     * @param obj  the object to test against.

     *

     * @return a boolean.

     */

    public boolean equals(final Object obj) {

        

        if (obj == null) {

            return false;   

        }

        

        if (obj == this) {

            return true;

        }

        

        if (!(obj instanceof HistogramType)) {

            return false;

        }

        

        final HistogramType t = (HistogramType) obj;

        if (!this.name.equals(t.name)) {

            return false;

        }

        

        return true;

        

    }



    /**

     * Returns a hash code value for the object.

     *

     * @return the hashcode

     */

    public int hashCode() {

        return this.name.hashCode();

    }



    /**

     * Ensures that serialization returns the unique instances.

     * 

     * @return the object.

     * 

     * @throws ObjectStreamException if there is a problem.

     */

    private Object readResolve() throws ObjectStreamException {

        if (this.equals(HistogramType.FREQUENCY)) {

            return HistogramType.FREQUENCY;

        }

        else if (this.equals(HistogramType.RELATIVE_FREQUENCY)) {

            return HistogramType.RELATIVE_FREQUENCY;

        }

        else if (this.equals(HistogramType.SCALE_AREA_TO_1)) {

            return HistogramType.SCALE_AREA_TO_1;

        }

        return null;

    }



}



