001/* ======================================================
002 * JFreeChart : a chart library for the Java(tm) platform
003 * ======================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert and Contributors.
006 *
007 * Project Info:  https://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 * FlowEntity.java
029 * ---------------
030 * (C) Copyright 2021-present, by David Gilbert and Contributors.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   Tracy Hiltbrand (equals/hashCode comply with EqualsVerifier);
034 *
035 */
036
037package org.jfree.chart.entity;
038
039import java.awt.Shape;
040import java.util.Objects;
041import org.jfree.chart.plot.flow.FlowPlot;
042import org.jfree.chart.util.Args;
043import org.jfree.data.flow.FlowKey;
044
045/**
046 * A chart entity representing the flow between two nodes in a {@link FlowPlot}.
047 * 
048 * @since 1.5.3
049 */
050public class FlowEntity extends ChartEntity {
051
052    /** The key. */
053    private final FlowKey key;
054    
055    /**
056     * Creates a new instance.
057     * 
058     * @param key  the key identifying the flow ({@code null} not permitted).
059     * @param area  the outline of the entity ({@code null} not permitted).
060     * @param toolTipText  the tool tip text.
061     * @param urlText  the URL text.
062     */
063    public FlowEntity(FlowKey key, Shape area, String toolTipText, String urlText) {
064        super(area, toolTipText, urlText);
065        Args.nullNotPermitted(key, "key");
066        this.key = key;
067    }
068    
069    /**
070     * Returns the key identifying the flow.
071     * 
072     * @return The flow key (never {@code null}). 
073     */
074    public FlowKey getKey() {
075        return this.key;
076    }
077
078    /**
079     * Returns a string representation of this instance, primarily for 
080     * debugging purposes.
081     * 
082     * @return A string. 
083     */
084    @Override
085    public String toString() {
086        return "[FlowEntity: " + this.key + "]";
087    }
088
089    /**
090     * Tests this instance for equality with an arbitrary object.
091     * 
092     * @param obj  the object ({@code null} permitted).
093     * 
094     * @return A boolean. 
095     */
096    @Override
097    public boolean equals(Object obj) {
098        if (!(obj instanceof FlowEntity)) {
099            return false;
100        }
101        FlowEntity that = (FlowEntity) obj;
102        if (!java.util.Objects.equals(this.key, that.key)) {
103            return false;
104        }
105        // fix the "equals not symmetric" problem
106        if (!that.canEqual(this)) {
107            return false;
108        }
109
110        return super.equals(obj);
111    }
112
113    /**
114     * Ensures symmetry between super/subclass implementations of equals. For
115     * more detail, see http://jqno.nl/equalsverifier/manual/inheritance.
116     *
117     * @param other Object
118     * 
119     * @return true ONLY if the parameter is THIS class type
120     */
121    @Override
122    public boolean canEqual(Object other) {
123        // fix the "equals not symmetric" problem
124        return (other instanceof FlowEntity);
125    }
126
127    @Override
128    public int hashCode() {
129        int hash = super.hashCode();
130        hash = 79 * hash + Objects.hashCode(this.key);
131        return hash;
132    }
133
134}