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