/* ===========================================================
* 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.]
*
* ------------------------
* DefaultValueDataset.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);
* 03-Mar-2005 : Implemented PublicCloneable (DG);
* ------------- JFREECHART 1.0.x ---------------------------------------------
* 30-Jan-2007 : Added explicit super() call in constructor (for clarity) (DG);
*
*/
package org.jfree.data.general;
import java.io.Serializable;
import org.jfree.util.ObjectUtilities;
import org.jfree.util.PublicCloneable;
/**
* A dataset that stores a single value (that is possibly <code>null</code>).
* This class provides a default implementation of the {@link ValueDataset}
* interface.
*/
public class DefaultValueDataset extends AbstractDataset
implements ValueDataset, Cloneable, PublicCloneable, Serializable {
/** For serialization. */
private static final long serialVersionUID = 8137521217249294891L;
/** The value. */
private Number value;
/**
* Constructs a new dataset, initially empty.
*/
public DefaultValueDataset() {
this(null);
}
/**
* Creates a new dataset with the specified value.
*
* @param value the value.
*/
public DefaultValueDataset(double value) {
this(new Double(value));
}
/**
* Creates a new dataset with the specified value.
*
* @param value the initial value (<code>null</code> permitted).
*/
public DefaultValueDataset(Number value) {
super();
this.value = value;
}
/**
* Returns the value.
*
* @return The value (possibly <code>null</code>).
*/
public Number getValue() {
return this.value;
}
/**
* Sets the value and sends a {@link DatasetChangeEvent} to all registered
* listeners.
*
* @param value the new value (<code>null</code> permitted).
*/
public void setValue(Number value) {
this.value = 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 ValueDataset) {
ValueDataset vd = (ValueDataset) obj;
return ObjectUtilities.equal(this.value, vd.getValue());
}
return false;
}
/**
* Returns a hash code.
*
* @return A hash code.
*/
public int hashCode() {
return (this.value != null ? this.value.hashCode() : 0);
}
}
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