001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2008, 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     * XYDataItem.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     * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
038     * 03-Feb-2004 : Fixed bug in equals() method (DG);
039     * 21-Feb-2005 : Added setY(double) method (DG);
040     * ------------- JFREECHART 1.0.x ---------------------------------------------
041     * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for
042     *               debugging use (DG);
043     *
044     */
045    
046    package org.jfree.data.xy;
047    
048    import java.io.Serializable;
049    
050    import org.jfree.util.ObjectUtilities;
051    
052    /**
053     * Represents one (x, y) data item for an {@link XYSeries}.
054     */
055    public class XYDataItem implements Cloneable, Comparable, Serializable {
056    
057        /** For serialization. */
058        private static final long serialVersionUID = 2751513470325494890L;
059    
060        /** The x-value (<code>null</code> not permitted). */
061        private Number x;
062    
063        /** The y-value. */
064        private Number y;
065    
066        /**
067         * Constructs a new data item.
068         *
069         * @param x  the x-value (<code>null</code> NOT permitted).
070         * @param y  the y-value (<code>null</code> permitted).
071         */
072        public XYDataItem(Number x, Number y) {
073            if (x == null) {
074                throw new IllegalArgumentException("Null 'x' argument.");
075            }
076            this.x = x;
077            this.y = y;
078        }
079    
080        /**
081         * Constructs a new data item.
082         *
083         * @param x  the x-value.
084         * @param y  the y-value.
085         */
086        public XYDataItem(double x, double y) {
087            this(new Double(x), new Double(y));
088        }
089    
090        /**
091         * Returns the x-value.
092         *
093         * @return The x-value (never <code>null</code>).
094         */
095        public Number getX() {
096            return this.x;
097        }
098    
099        /**
100         * Returns the x-value as a double primitive.
101         *
102         * @return The x-value.
103         *
104         * @see #getX()
105         * @see #getYValue()
106         *
107         * @since 1.0.9
108         */
109        public double getXValue() {
110            // this.x is not allowed to be null...
111            return this.x.doubleValue();
112        }
113    
114        /**
115         * Returns the y-value.
116         *
117         * @return The y-value (possibly <code>null</code>).
118         */
119        public Number getY() {
120            return this.y;
121        }
122    
123        /**
124         * Returns the y-value as a double primitive.
125         *
126         * @return The y-value.
127         *
128         * @see #getY()
129         * @see #getXValue()
130         *
131         * @since 1.0.9
132         */
133        public double getYValue() {
134            double result = Double.NaN;
135            if (this.y != null) {
136                result = this.y.doubleValue();
137            }
138            return result;
139        }
140    
141        /**
142         * Sets the y-value for this data item.  Note that there is no
143         * corresponding method to change the x-value.
144         *
145         * @param y  the new y-value.
146         */
147        public void setY(double y) {
148            setY(new Double(y));
149        }
150    
151        /**
152         * Sets the y-value for this data item.  Note that there is no
153         * corresponding method to change the x-value.
154         *
155         * @param y  the new y-value (<code>null</code> permitted).
156         */
157        public void setY(Number y) {
158            this.y = y;
159        }
160    
161        /**
162         * Returns an integer indicating the order of this object relative to
163         * another object.
164         * <P>
165         * For the order we consider only the x-value:
166         * negative == "less-than", zero == "equal", positive == "greater-than".
167         *
168         * @param o1  the object being compared to.
169         *
170         * @return An integer indicating the order of this data pair object
171         *      relative to another object.
172         */
173        public int compareTo(Object o1) {
174    
175            int result;
176    
177            // CASE 1 : Comparing to another TimeSeriesDataPair object
178            // -------------------------------------------------------
179            if (o1 instanceof XYDataItem) {
180                XYDataItem dataItem = (XYDataItem) o1;
181                double compare = this.x.doubleValue()
182                                 - dataItem.getX().doubleValue();
183                if (compare > 0.0) {
184                    result = 1;
185                }
186                else {
187                    if (compare < 0.0) {
188                        result = -1;
189                    }
190                    else {
191                        result = 0;
192                    }
193                }
194            }
195    
196            // CASE 2 : Comparing to a general object
197            // ---------------------------------------------
198            else {
199                // consider time periods to be ordered after general objects
200                result = 1;
201            }
202    
203            return result;
204    
205        }
206    
207        /**
208         * Returns a clone of this object.
209         *
210         * @return A clone.
211         *
212         * @throws CloneNotSupportedException not thrown by this class, but
213         *         subclasses may differ.
214         */
215        public Object clone() throws CloneNotSupportedException {
216            return super.clone();
217        }
218    
219        /**
220         * Tests if this object is equal to another.
221         *
222         * @param obj  the object to test against for equality (<code>null</code>
223         *             permitted).
224         *
225         * @return A boolean.
226         */
227        public boolean equals(Object obj) {
228            if (obj == this) {
229                return true;
230            }
231            if (!(obj instanceof XYDataItem)) {
232                return false;
233            }
234            XYDataItem that = (XYDataItem) obj;
235            if (!this.x.equals(that.x)) {
236                return false;
237            }
238            if (!ObjectUtilities.equal(this.y, that.y)) {
239                return false;
240            }
241            return true;
242        }
243    
244        /**
245         * Returns a hash code.
246         *
247         * @return A hash code.
248         */
249        public int hashCode() {
250            int result;
251            result = this.x.hashCode();
252            result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
253            return result;
254        }
255    
256        /**
257         * Returns a string representing this instance, primarily for debugging
258         * use.
259         *
260         * @return A string.
261         */
262        public String toString() {
263            return "[" + getXValue() + ", " + getYValue() + "]";
264        }
265    
266    }