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1: /* =========================================================== 2: * JFreeChart : a free chart library for the Java(tm) platform 3: * =========================================================== 4: * 5: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. 6: * 7: * Project Info: http://www.jfree.org/jfreechart/index.html 8: * 9: * This library is free software; you can redistribute it and/or modify it 10: * under the terms of the GNU Lesser General Public License as published by 11: * the Free Software Foundation; either version 2.1 of the License, or 12: * (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but 15: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 16: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 17: * License for more details. 18: * 19: * You should have received a copy of the GNU Lesser General Public 20: * License along with this library; if not, write to the Free Software 21: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 22: * USA. 23: * 24: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 25: * in the United States and other countries.] 26: * 27: * ------------------------ 28: * DefaultValueDataset.java 29: * ------------------------ 30: * (C) Copyright 2003-2005, by Object Refinery Limited. 31: * 32: * Original Author: David Gilbert (for Object Refinery Limited); 33: * Contributor(s): -; 34: * 35: * $Id $ 36: * 37: * Changes 38: * ------- 39: * 27-Mar-2003 : Version 1 (DG); 40: * 18-Aug-2003 : Implemented Cloneable (DG); 41: * 03-Mar-2005 : Implemented PublicCloneable (DG); 42: * 43: */ 44: 45: package org.jfree.data.general; 46: 47: import java.io.Serializable; 48: 49: import org.jfree.util.ObjectUtilities; 50: import org.jfree.util.PublicCloneable; 51: 52: /** 53: * A dataset that stores a single value. This class provides a default 54: * implementation of the {@link ValueDataset} interface. 55: */ 56: public class DefaultValueDataset extends AbstractDataset 57: implements ValueDataset, 58: Cloneable, PublicCloneable, 59: Serializable { 60: 61: /** For serialization. */ 62: private static final long serialVersionUID = 8137521217249294891L; 63: 64: /** The value. */ 65: private Number value; 66: 67: /** 68: * Constructs a new dataset, initially empty. 69: */ 70: public DefaultValueDataset() { 71: this(null); 72: } 73: 74: /** 75: * Creates a new dataset. 76: * 77: * @param value the value. 78: */ 79: public DefaultValueDataset(double value) { 80: this(new Double(value)); 81: } 82: 83: /** 84: * Creates a new dataset. 85: * 86: * @param value the initial value. 87: */ 88: public DefaultValueDataset(Number value) { 89: this.value = value; 90: } 91: 92: /** 93: * Returns the value. 94: * 95: * @return The value (possibly <code>null</code>). 96: */ 97: public Number getValue() { 98: return this.value; 99: } 100: 101: /** 102: * Sets the value and sends a {@link DatasetChangeEvent} to all registered 103: * listeners. 104: * 105: * @param value the new value (<code>null</code> permitted). 106: */ 107: public void setValue(Number value) { 108: this.value = value; 109: notifyListeners(new DatasetChangeEvent(this, this)); 110: } 111: 112: /** 113: * Tests this dataset for equality with an arbitrary object. 114: * 115: * @param obj the object. 116: * 117: * @return A boolean. 118: */ 119: public boolean equals(Object obj) { 120: 121: if (obj == null) { 122: return false; 123: } 124: 125: if (obj == this) { 126: return true; 127: } 128: 129: if (obj instanceof ValueDataset) { 130: ValueDataset vd = (ValueDataset) obj; 131: return ObjectUtilities.equal(this.value, vd.getValue()); 132: } 133: 134: return false; 135: } 136: 137: /** 138: * Returns a hash code. 139: * 140: * @return A hash code. 141: */ 142: public int hashCode() { 143: return (this.value != null ? this.value.hashCode() : 0); 144: } 145: 146: }