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 * TimePeriodAnchor.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 * 30-Jul-2003 : Version 1 (DG);
038 * 01-Mar-2004 : Added readResolve() method (DG);
039 *
040 */
041
042package org.jfree.data.time;
043
044import java.io.ObjectStreamException;
045import java.io.Serializable;
046
047/**
048 * Used to indicate one of three positions in a time period:
049 * <code>START</code>, <code>MIDDLE</code> and <code>END</code>.
050 */
051public final class TimePeriodAnchor implements Serializable {
052
053    /** For serialization. */
054    private static final long serialVersionUID = 2011955697457548862L;
055
056    /** Start of period. */
057    public static final TimePeriodAnchor START
058        = new TimePeriodAnchor("TimePeriodAnchor.START");
059
060    /** Middle of period. */
061    public static final TimePeriodAnchor MIDDLE
062        = new TimePeriodAnchor("TimePeriodAnchor.MIDDLE");
063
064    /** End of period. */
065    public static final TimePeriodAnchor END
066        = new TimePeriodAnchor("TimePeriodAnchor.END");
067
068    /** The name. */
069    private String name;
070
071    /**
072     * Private constructor.
073     *
074     * @param name  the name.
075     */
076    private TimePeriodAnchor(String name) {
077        this.name = name;
078    }
079
080    /**
081     * Returns a string representing the object.
082     *
083     * @return The string.
084     */
085    @Override
086    public String toString() {
087        return this.name;
088    }
089
090    /**
091     * Returns <code>true</code> if this object is equal to the specified
092     * object, and <code>false</code> otherwise.
093     *
094     * @param obj  the other object.
095     *
096     * @return A boolean.
097     */
098    @Override
099    public boolean equals(Object obj) {
100
101        if (this == obj) {
102            return true;
103        }
104        if (!(obj instanceof TimePeriodAnchor)) {
105            return false;
106        }
107
108        TimePeriodAnchor position = (TimePeriodAnchor) obj;
109        if (!this.name.equals(position.name)) {
110            return false;
111        }
112
113        return true;
114    }
115
116    /**
117     * Returns a hash code value for the object.
118     *
119     * @return The hashcode
120     */
121    @Override
122    public int hashCode() {
123        return this.name.hashCode();
124    }
125
126    /**
127     * Ensures that serialization returns the unique instances.
128     *
129     * @return The object.
130     *
131     * @throws ObjectStreamException if there is a problem.
132     */
133    private Object readResolve() throws ObjectStreamException {
134        if (this.equals(TimePeriodAnchor.START)) {
135            return TimePeriodAnchor.START;
136        }
137        else if (this.equals(TimePeriodAnchor.MIDDLE)) {
138            return TimePeriodAnchor.MIDDLE;
139        }
140        else if (this.equals(TimePeriodAnchor.END)) {
141            return TimePeriodAnchor.END;
142        }
143        return null;
144    }
145
146}