001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it 
010 * under the terms of the GNU Lesser General Public License as published by 
011 * the Free Software Foundation; either version 2.1 of the License, or 
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but 
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022 * USA.  
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025 * in the United States and other countries.]
026 *
027 * --------------------------
028 * DatasetRenderingOrder.java
029 * --------------------------
030 * (C) Copyright 2003-2007, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 02-May-2003 : Version 1 (DG);
038 * 02-Jun-2004 : Changed 'STANDARD' --> 'FORWARD' (DG);
039 *
040 */
041
042package org.jfree.chart.plot;
043
044import java.io.ObjectStreamException;
045import java.io.Serializable;
046
047/**
048 * Defines the tokens that indicate the rendering order for datasets in a 
049 * {@link org.jfree.chart.plot.CategoryPlot} or an 
050 * {@link org.jfree.chart.plot.XYPlot}.
051 */
052public final class DatasetRenderingOrder implements Serializable {
053
054    /** For serialization. */
055    private static final long serialVersionUID = -600593412366385072L;    
056
057    /** 
058     * Render datasets in the order 0, 1, 2, ..., N-1, where N is the number 
059     * of datasets. 
060     */
061    public static final DatasetRenderingOrder FORWARD
062        = new DatasetRenderingOrder("DatasetRenderingOrder.FORWARD");
063
064    /** 
065     * Render datasets in the order N-1, N-2, ..., 2, 1, 0, where N is the 
066     * number of datasets. 
067     */
068    public static final DatasetRenderingOrder REVERSE
069        = new DatasetRenderingOrder("DatasetRenderingOrder.REVERSE");
070
071    /** The name. */
072    private String name;
073
074    /**
075     * Private constructor.
076     *
077     * @param name  the name.
078     */
079    private DatasetRenderingOrder(String name) {
080        this.name = name;
081    }
082
083    /**
084     * Returns a string representing the object.
085     *
086     * @return The string (never <code>null</code>).
087     */
088    public String toString() {
089        return this.name;
090    }
091
092    /**
093     * Returns <code>true</code> if this object is equal to the specified 
094     * object, and <code>false</code> otherwise.
095     *
096     * @param o  the other object.
097     *
098     * @return A boolean.
099     */
100    public boolean equals(Object o) {
101
102        if (this == o) {
103            return true;
104        }
105        if (!(o instanceof DatasetRenderingOrder)) {
106            return false;
107        }
108
109        DatasetRenderingOrder order = (DatasetRenderingOrder) o;
110        if (!this.name.equals(order.toString())) {
111            return false;
112        }
113
114        return true;
115
116    }
117    
118    /**
119     * Ensures that serialization returns the unique instances.
120     * 
121     * @return The object.
122     * 
123     * @throws ObjectStreamException if there is a problem.
124     */
125    private Object readResolve() throws ObjectStreamException {
126        if (this.equals(DatasetRenderingOrder.FORWARD)) {
127            return DatasetRenderingOrder.FORWARD;
128        }
129        else if (this.equals(DatasetRenderingOrder.REVERSE)) {
130            return DatasetRenderingOrder.REVERSE;
131        }      
132        return null;
133    }
134
135}