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 * XYItemKey.java
029 * --------------
030 * (C) Copyright 2014-2022, 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;
043import org.jfree.data.ItemKey;
044
045/**
046 * An object that references one data item in an {@link XYZDataset}.  This is 
047 * used internally to track the data item that a 3D object is related to, if
048 * any (and later that link is used for chart interaction).  Instances of
049 * this class are immutable.
050 * 
051 * @param <S> the series key type.
052 */
053public class XYItemKey<S extends Comparable<S>> implements ItemKey, 
054        Comparable<XYItemKey<S>>, Serializable {
055    
056    /** A key identifying a series in the dataset. */
057    private final S seriesKey;
058    
059    /** The index of an item within a series. */
060    private final int itemIndex;
061    
062    /**
063     * Creates a new instance.
064     * 
065     * @param seriesKey  the series key.
066     * @param itemIndex  the item index.
067     */
068    public XYItemKey(S seriesKey, int itemIndex) {
069        Args.nullNotPermitted(seriesKey, "seriesKey");
070        this.seriesKey = seriesKey;
071        this.itemIndex = itemIndex;
072    }
073    
074    /**
075     * Returns the series key.
076     * 
077     * @return The series key (never {@code null}). 
078     */
079    public S getSeriesKey() {
080        return this.seriesKey;
081    }
082    
083    /**
084     * Returns the item index.
085     * 
086     * @return The item index.
087     */
088    public int getItemIndex() {
089        return this.itemIndex;
090    }
091    
092    /**
093     * Tests this instance for equality with an arbitrary object.
094     * 
095     * @param obj  the object to test ({@code null} permitted).
096     * 
097     * @return A boolean. 
098     */
099    @Override
100    public boolean equals(Object obj) {
101        if (obj == this) {
102            return true;
103        }
104        if (!(obj instanceof XYItemKey)) {
105            return false;
106        }
107        XYItemKey that = (XYItemKey) obj;
108        if (!this.seriesKey.equals(that.seriesKey)) {
109            return false;
110        }
111        if (this.itemIndex != that.itemIndex) {
112            return false;
113        }
114        return true;
115    }
116
117    @Override
118    public int hashCode() {
119        int hash = 7;
120        hash = 41 * hash + Objects.hashCode(this.seriesKey);
121        hash = 41 * hash + this.itemIndex;
122        return hash;
123    }
124
125    @Override
126    public String toJSONString() {
127        StringBuilder sb = new StringBuilder();
128        sb.append("{\"seriesKey\": \"").append(this.seriesKey.toString());
129        sb.append("\", ");
130        sb.append("\"itemIndex\": ").append(this.itemIndex).append("}");
131        return sb.toString();
132    }
133
134    @Override
135    public String toString() {
136        StringBuilder sb = new StringBuilder();
137        sb.append("XYItemKey[seriesKey=");
138        sb.append(this.seriesKey.toString()).append(",item=");
139        sb.append(itemIndex);
140        sb.append("]");
141        return sb.toString();
142    }
143
144    @Override
145    public int compareTo(XYItemKey<S> key) {
146        int result = this.seriesKey.compareTo(key.seriesKey);
147        if (result == 0) {
148            result = this.itemIndex - key.itemIndex;
149        }
150        return result;
151    }
152
153}
154