001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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     * TimePeriodValue.java
029     * --------------------
030     * (C) Copyright 2003-2006, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: TimePeriodValue.java,v 1.4.2.2 2006/10/03 15:16:33 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 22-Apr-2003 : Version 1 (DG);
040     * 03-Oct-2006 : Added null argument check to constructor (DG);
041     *
042     */
043    
044    package org.jfree.data.time;
045    
046    import java.io.Serializable;
047    
048    /**
049     * Represents a time period and an associated value.
050     */
051    public class TimePeriodValue implements Cloneable, Serializable {
052    
053        /** For serialization. */
054        private static final long serialVersionUID = 3390443360845711275L;
055        
056        /** The time period. */
057        private TimePeriod period;
058    
059        /** The value associated with the time period. */
060        private Number value;
061    
062        /**
063         * Constructs a new data item.
064         *
065         * @param period  the time period (<code>null</code> not permitted).
066         * @param value  the value associated with the time period.
067         * 
068         * @throws IllegalArgumentException if <code>period</code> is 
069         *     <code>null</code>.
070         */
071        public TimePeriodValue(TimePeriod period, Number value) {
072            if (period == null) {
073                throw new IllegalArgumentException("Null 'period' argument.");
074            }
075            this.period = period;
076            this.value = value;
077        }
078    
079        /**
080         * Constructs a new data item.
081         *
082         * @param period  the time period (<code>null</code> not permitted).
083         * @param value  the value associated with the time period.
084         * 
085         * @throws IllegalArgumentException if <code>period</code> is 
086         *     <code>null</code>.
087         */
088        public TimePeriodValue(TimePeriod period, double value) {
089            this(period, new Double(value));
090        }
091    
092        /**
093         * Returns the time period.
094         *
095         * @return The time period (never <code>null</code>).
096         */
097        public TimePeriod getPeriod() {
098            return this.period;
099        }
100    
101        /**
102         * Returns the value.
103         *
104         * @return The value (possibly <code>null</code>).
105         * 
106         * @see #setValue(Number)
107         */
108        public Number getValue() {
109            return this.value;
110        }
111    
112        /**
113         * Sets the value for this data item.
114         *
115         * @param value  the new value (<code>null</code> permitted).
116         * 
117         * @see #getValue()
118         */
119        public void setValue(Number value) {
120            this.value = value;
121        }
122    
123        /**
124         * Tests this object for equality with the target object.
125         *
126         * @param obj  the object (<code>null</code> permitted).
127         *
128         * @return A boolean.
129         */
130        public boolean equals(Object obj) {
131            if (this == obj) {
132                return true;
133            }
134            if (!(obj instanceof TimePeriodValue)) {
135                return false;
136            }
137    
138            TimePeriodValue timePeriodValue = (TimePeriodValue) obj;
139    
140            if (this.period != null ? !this.period.equals(timePeriodValue.period) 
141                    : timePeriodValue.period != null) {
142                return false;
143            }
144            if (this.value != null ? !this.value.equals(timePeriodValue.value) 
145                    : timePeriodValue.value != null) {
146                return false;
147            }
148    
149            return true;
150        }
151    
152        /**
153         * Returns a hash code value for the object.
154         *
155         * @return The hashcode
156         */
157        public int hashCode() {
158            int result;
159            result = (this.period != null ? this.period.hashCode() : 0);
160            result = 29 * result + (this.value != null ? this.value.hashCode() : 0);
161            return result;
162        }
163    
164        /**
165         * Clones the object.
166         * <P>
167         * Note: no need to clone the period or value since they are immutable 
168         * classes.
169         *
170         * @return A clone.
171         */
172        public Object clone() {
173            Object clone = null;
174            try {
175                clone = super.clone();
176            }
177            catch (CloneNotSupportedException e) { // won't get here...
178                e.printStackTrace();
179            }
180            return clone;
181        }
182    
183    }