/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* -----------------------------
* DefaultKeyedValueDataset.java
* -----------------------------
* (C) Copyright 2003-2008, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 27-Mar-2003 : Version 1 (DG);
* 18-Aug-2003 : Implemented Cloneable (DG);
*
*/
package org.jfree.data.general;
import java.io.Serializable;
import org.jfree.data.DefaultKeyedValue;
import org.jfree.data.KeyedValue;
import org.jfree.util.ObjectUtilities;
/**
* A default implementation of the {@link KeyedValueDataset} interface.
*/
public class DefaultKeyedValueDataset extends AbstractDataset
implements KeyedValueDataset, Serializable {
/** For serialization. */
private static final long serialVersionUID = -8149484339560406750L;
/** Storage for the data. */
private KeyedValue data;
/**
* Constructs a new dataset, initially empty.
*/
public DefaultKeyedValueDataset() {
this(null);
}
/**
* Creates a new dataset with the specified initial value.
*
* @param key the key.
* @param value the value (<code>null</code> permitted).
*/
public DefaultKeyedValueDataset(Comparable key, Number value) {
this(new DefaultKeyedValue(key, value));
}
/**
* Creates a new dataset that uses the data from a {@link KeyedValue}
* instance.
*
* @param data the data (<code>null</code> permitted).
*/
public DefaultKeyedValueDataset(KeyedValue data) {
this.data = data;
}
/**
* Returns the key associated with the value, or <code>null</code> if the
* dataset has no data item.
*
* @return The key.
*/
public Comparable getKey() {
Comparable result = null;
if (this.data != null) {
result = this.data.getKey();
}
return result;
}
/**
* Returns the value.
*
* @return The value (possibly <code>null</code>).
*/
public Number getValue() {
Number result = null;
if (this.data != null) {
result = this.data.getValue();
}
return result;
}
/**
* Updates the value.
*
* @param value the new value (<code>null</code> permitted).
*/
public void updateValue(Number value) {
if (this.data == null) {
throw new RuntimeException("updateValue: can't update null.");
}
setValue(this.data.getKey(), value);
}
/**
* Sets the value for the dataset and sends a {@link DatasetChangeEvent} to
* all registered listeners.
*
* @param key the key.
* @param value the value (<code>null</code> permitted).
*/
public void setValue(Comparable key, Number value) {
this.data = new DefaultKeyedValue(key, value);
notifyListeners(new DatasetChangeEvent(this, this));
}
/**
* Tests this dataset for equality with an arbitrary object.
*
* @param obj the object (<code>null</code> permitted).
*
* @return A boolean.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof KeyedValueDataset)) {
return false;
}
KeyedValueDataset that = (KeyedValueDataset) obj;
if (this.data == null) {
if (that.getKey() != null || that.getValue() != null) {
return false;
}
return true;
}
if (!ObjectUtilities.equal(this.data.getKey(), that.getKey())) {
return false;
}
if (!ObjectUtilities.equal(this.data.getValue(), that.getValue())) {
return false;
}
return true;
}
/**
* Returns a hash code.
*
* @return A hash code.
*/
public int hashCode() {
return (this.data != null ? this.data.hashCode() : 0);
}
/**
* Creates a clone of the dataset.
*
* @return A clone.
*
* @throws CloneNotSupportedException This class will not throw this
* exception, but subclasses (if any) might.
*/
public Object clone() throws CloneNotSupportedException {
DefaultKeyedValueDataset clone
= (DefaultKeyedValueDataset) super.clone();
return clone;
}
}
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