001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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     * TimePeriodAnchor.java
029     * ---------------------
030     * (C) Copyright 2003, 2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: TimePeriodAnchor.java,v 1.5.2.1 2005/10/25 21:35:24 mungady Exp $
036     *
037     * Changes:
038     * --------
039     * 30-Jul-2003 : Version 1 (DG);
040     * 01-Mar-2004 : Added readResolve() method (DG);
041     *
042     */
043    
044    package org.jfree.data.time;
045    
046    import java.io.ObjectStreamException;
047    import java.io.Serializable;
048    
049    /**
050     * Used to indicate one of three positions in a time period: 
051     * <code>START</code>, <code>MIDDLE</code> and <code>END</code>.
052     */
053    public final class TimePeriodAnchor implements Serializable {
054    
055        /** For serialization. */
056        private static final long serialVersionUID = 2011955697457548862L;
057        
058        /** Start of period. */
059        public static final TimePeriodAnchor START 
060            = new TimePeriodAnchor("TimePeriodAnchor.START");
061    
062        /** Middle of period. */
063        public static final TimePeriodAnchor MIDDLE 
064            = new TimePeriodAnchor("TimePeriodAnchor.MIDDLE");
065    
066        /** End of period. */
067        public static final TimePeriodAnchor END 
068            = new TimePeriodAnchor("TimePeriodAnchor.END");
069    
070        /** The name. */
071        private String name;
072    
073        /**
074         * Private constructor.
075         *
076         * @param name  the name.
077         */
078        private TimePeriodAnchor(String name) {
079            this.name = name;
080        }
081    
082        /**
083         * Returns a string representing the object.
084         *
085         * @return The string.
086         */
087        public String toString() {
088            return this.name;
089        }
090    
091        /**
092         * Returns <code>true</code> if this object is equal to the specified 
093         * object, and <code>false</code> otherwise.
094         *
095         * @param obj  the other object.
096         *
097         * @return A boolean.
098         */
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        public int hashCode() {
122            return this.name.hashCode();
123        }
124        
125        /**
126         * Ensures that serialization returns the unique instances.
127         * 
128         * @return The object.
129         * 
130         * @throws ObjectStreamException if there is a problem.
131         */
132        private Object readResolve() throws ObjectStreamException {
133            if (this.equals(TimePeriodAnchor.START)) {
134                return TimePeriodAnchor.START;
135            }
136            else if (this.equals(TimePeriodAnchor.MIDDLE)) {
137                return TimePeriodAnchor.MIDDLE;
138            }
139            else if (this.equals(TimePeriodAnchor.END)) {
140                return TimePeriodAnchor.END;
141            }
142            return null;
143        }
144    
145    }