001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2022, by David Gilbert 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 * XYDataItem.java
029 * ---------------
030 * (C) Copyright 2003-2022, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.data.xy;
038
039import java.io.Serializable;
040import java.util.Objects;
041
042import org.jfree.chart.internal.Args;
043
044/**
045 * Represents one (x, y) data item for an {@link XYSeries}.  Note that
046 * subclasses are REQUIRED to support cloning.
047 */
048public class XYDataItem implements Cloneable, Comparable<XYDataItem>, Serializable {
049
050    /** For serialization. */
051    private static final long serialVersionUID = 2751513470325494890L;
052
053    /** The x-value ({@code null} not permitted). */
054    private Number x;
055
056    /** The y-value. */
057    private Number y;
058
059    /**
060     * Constructs a new data item.
061     *
062     * @param x  the x-value ({@code null} NOT permitted).
063     * @param y  the y-value ({@code null} permitted).
064     */
065    public XYDataItem(Number x, Number y) {
066        Args.nullNotPermitted(x, "x");
067        this.x = x;
068        this.y = y;
069    }
070
071    /**
072     * Constructs a new data item.
073     *
074     * @param x  the x-value.
075     * @param y  the y-value.
076     */
077    public XYDataItem(double x, double y) {
078        this(Double.valueOf(x), Double.valueOf(y));
079    }
080
081    /**
082     * Returns the x-value.
083     *
084     * @return The x-value (never {@code null}).
085     */
086    public Number getX() {
087        return this.x;
088    }
089
090    /**
091     * Returns the x-value as a double primitive.
092     *
093     * @return The x-value.
094     *
095     * @see #getX()
096     * @see #getYValue()
097     */
098    public double getXValue() {
099        // this.x is not allowed to be null...
100        return this.x.doubleValue();
101    }
102
103    /**
104     * Returns the y-value.
105     *
106     * @return The y-value (possibly {@code null}).
107     */
108    public Number getY() {
109        return this.y;
110    }
111
112    /**
113     * Returns the y-value as a double primitive.
114     *
115     * @return The y-value.
116     *
117     * @see #getY()
118     * @see #getXValue()
119     */
120    public double getYValue() {
121        double result = Double.NaN;
122        if (this.y != null) {
123            result = this.y.doubleValue();
124        }
125        return result;
126    }
127
128    /**
129     * Sets the y-value for this data item.  Note that there is no
130     * corresponding method to change the x-value.
131     *
132     * @param y  the new y-value.
133     */
134    public void setY(double y) {
135        setY(Double.valueOf(y));
136    }
137
138    /**
139     * Sets the y-value for this data item.  Note that there is no
140     * corresponding method to change the x-value.
141     *
142     * @param y  the new y-value ({@code null} permitted).
143     */
144    public void setY(Number y) {
145        this.y = y;
146    }
147
148    /**
149     * Returns an integer indicating the order of this object relative to
150     * another object.
151     * <P>
152     * For the order we consider only the x-value:
153     * negative == "less-than", zero == "equal", positive == "greater-than".
154     *
155     * @param other  the data item being compared to.
156     *
157     * @return An integer indicating the order of this data pair object
158     *      relative to another object.
159     */
160    @Override
161    public int compareTo(XYDataItem other) {
162        int result;
163        double compare = this.x.doubleValue() - other.getX().doubleValue();
164        if (compare > 0.0) {
165            result = 1;
166        } else {
167            if (compare < 0.0) {
168                result = -1;
169            } else {
170                result = 0;
171            }
172        }
173        return result;
174    }
175
176    /**
177     * Returns a clone of this object.
178     *
179     * @return A clone.
180     */
181    @Override
182    public Object clone() {
183        Object clone = null;
184        try {
185            clone = super.clone();
186        }
187        catch (CloneNotSupportedException e) { // won't get here...
188            e.printStackTrace();
189        }
190        return clone;
191    }
192
193    /**
194     * Tests if this object is equal to another.
195     *
196     * @param obj  the object to test against for equality ({@code null}
197     *             permitted).
198     *
199     * @return A boolean.
200     */
201    @Override
202    public boolean equals(Object obj) {
203        if (obj == this) {
204            return true;
205        }
206        if (!(obj instanceof XYDataItem)) {
207            return false;
208        }
209        XYDataItem that = (XYDataItem) obj;
210        if (!this.x.equals(that.x)) {
211            return false;
212        }
213        if (!Objects.equals(this.y, that.y)) {
214            return false;
215        }
216        return true;
217    }
218
219    /**
220     * Returns a hash code.
221     *
222     * @return A hash code.
223     */
224    @Override
225    public int hashCode() {
226        int result;
227        result = this.x.hashCode();
228        result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
229        return result;
230    }
231
232    /**
233     * Returns a string representing this instance, primarily for debugging
234     * use.
235     *
236     * @return A string.
237     */
238    @Override
239    public String toString() {
240        return "[" + getXValue() + ", " + getYValue() + "]";
241    }
242
243}