001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * -------------------
028 * CategoryAnchor.java
029 * -------------------
030 * (C) Copyright 2003-2008, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes:
036 * --------
037 * 04-Jul-2003 : Version 1 (DG);
038 *
039 */
040
041package org.jfree.chart.axis;
042
043import java.io.ObjectStreamException;
044import java.io.Serializable;
045
046/**
047 * Used to indicate one of three positions within a category:
048 * <code>START</code>, <code>MIDDLE</code> and <code>END</code>.
049 */
050public final class CategoryAnchor implements Serializable {
051
052    /** For serialization. */
053    private static final long serialVersionUID = -2604142742210173810L;
054
055    /** Start of period. */
056    public static final CategoryAnchor START
057        = new CategoryAnchor("CategoryAnchor.START");
058
059    /** Middle of period. */
060    public static final CategoryAnchor MIDDLE
061        = new CategoryAnchor("CategoryAnchor.MIDDLE");
062
063    /** End of period. */
064    public static final CategoryAnchor END
065        = new CategoryAnchor("CategoryAnchor.END");
066
067    /** The name. */
068    private String name;
069
070    /**
071     * Private constructor.
072     *
073     * @param name  the name.
074     */
075    private CategoryAnchor(String name) {
076        this.name = name;
077    }
078
079    /**
080     * Returns a string representing the object.
081     *
082     * @return The string.
083     */
084    @Override
085    public String toString() {
086        return this.name;
087    }
088
089    /**
090     * Returns <code>true</code> if this object is equal to the specified
091     * object, and <code>false</code> otherwise.
092     *
093     * @param obj  the other object.
094     *
095     * @return A boolean.
096     */
097    @Override
098    public boolean equals(Object obj) {
099        if (this == obj) {
100            return true;
101        }
102        if (!(obj instanceof CategoryAnchor)) {
103            return false;
104        }
105        CategoryAnchor position = (CategoryAnchor) obj;
106        if (!this.name.equals(position.toString())) {
107            return false;
108        }
109        return true;
110    }
111
112    /**
113     * Ensures that serialization returns the unique instances.
114     *
115     * @return The object.
116     *
117     * @throws ObjectStreamException if there is a problem.
118     */
119    private Object readResolve() throws ObjectStreamException {
120        if (this.equals(CategoryAnchor.START)) {
121            return CategoryAnchor.START;
122        }
123        else if (this.equals(CategoryAnchor.MIDDLE)) {
124            return CategoryAnchor.MIDDLE;
125        }
126        else if (this.equals(CategoryAnchor.END)) {
127            return CategoryAnchor.END;
128        }
129        return null;
130    }
131
132}