jfreechart example source code file (XYDataItem.java)

This example jfreechart source code file (XYDataItem.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

clonenotsupportedexception, clonenotsupportedexception, comparable, double, double, illegalargumentexception, io, null, number, number, object, serializable, string, xydataitem, xydataitem

The jfreechart XYDataItem.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * ---------------
 * XYDataItem.java
 * ---------------
 * (C) Copyright 2003-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
 * 03-Feb-2004 : Fixed bug in equals() method (DG);
 * 21-Feb-2005 : Added setY(double) method (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for
 *               debugging use (DG);
 *
 */

package org.jfree.data.xy;

import java.io.Serializable;

import org.jfree.util.ObjectUtilities;

/**
 * Represents one (x, y) data item for an {@link XYSeries}.
 */
public class XYDataItem implements Cloneable, Comparable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 2751513470325494890L;

    /** The x-value (<code>null not permitted). */
    private Number x;

    /** The y-value. */
    private Number y;

    /**
     * Constructs a new data item.
     *
     * @param x  the x-value (<code>null NOT permitted).
     * @param y  the y-value (<code>null permitted).
     */
    public XYDataItem(Number x, Number y) {
        if (x == null) {
            throw new IllegalArgumentException("Null 'x' argument.");
        }
        this.x = x;
        this.y = y;
    }

    /**
     * Constructs a new data item.
     *
     * @param x  the x-value.
     * @param y  the y-value.
     */
    public XYDataItem(double x, double y) {
        this(new Double(x), new Double(y));
    }

    /**
     * Returns the x-value.
     *
     * @return The x-value (never <code>null).
     */
    public Number getX() {
        return this.x;
    }

    /**
     * Returns the x-value as a double primitive.
     *
     * @return The x-value.
     *
     * @see #getX()
     * @see #getYValue()
     *
     * @since 1.0.9
     */
    public double getXValue() {
        // this.x is not allowed to be null...
        return this.x.doubleValue();
    }

    /**
     * Returns the y-value.
     *
     * @return The y-value (possibly <code>null).
     */
    public Number getY() {
        return this.y;
    }

    /**
     * Returns the y-value as a double primitive.
     *
     * @return The y-value.
     *
     * @see #getY()
     * @see #getXValue()
     *
     * @since 1.0.9
     */
    public double getYValue() {
        double result = Double.NaN;
        if (this.y != null) {
            result = this.y.doubleValue();
        }
        return result;
    }

    /**
     * Sets the y-value for this data item.  Note that there is no
     * corresponding method to change the x-value.
     *
     * @param y  the new y-value.
     */
    public void setY(double y) {
        setY(new Double(y));
    }

    /**
     * Sets the y-value for this data item.  Note that there is no
     * corresponding method to change the x-value.
     *
     * @param y  the new y-value (<code>null permitted).
     */
    public void setY(Number y) {
        this.y = y;
    }

    /**
     * Returns an integer indicating the order of this object relative to
     * another object.
     * <P>
     * For the order we consider only the x-value:
     * negative == "less-than", zero == "equal", positive == "greater-than".
     *
     * @param o1  the object being compared to.
     *
     * @return An integer indicating the order of this data pair object
     *      relative to another object.
     */
    public int compareTo(Object o1) {

        int result;

        // CASE 1 : Comparing to another TimeSeriesDataPair object
        // -------------------------------------------------------
        if (o1 instanceof XYDataItem) {
            XYDataItem dataItem = (XYDataItem) o1;
            double compare = this.x.doubleValue()
                             - dataItem.getX().doubleValue();
            if (compare > 0.0) {
                result = 1;
            }
            else {
                if (compare < 0.0) {
                    result = -1;
                }
                else {
                    result = 0;
                }
            }
        }

        // CASE 2 : Comparing to a general object
        // ---------------------------------------------
        else {
            // consider time periods to be ordered after general objects
            result = 1;
        }

        return result;

    }

    /**
     * Returns a clone of this object.
     *
     * @return A clone.
     *
     * @throws CloneNotSupportedException not thrown by this class, but
     *         subclasses may differ.
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    /**
     * Tests if this object is equal to another.
     *
     * @param obj  the object to test against for equality (<code>null
     *             permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof XYDataItem)) {
            return false;
        }
        XYDataItem that = (XYDataItem) obj;
        if (!this.x.equals(that.x)) {
            return false;
        }
        if (!ObjectUtilities.equal(this.y, that.y)) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code.
     *
     * @return A hash code.
     */
    public int hashCode() {
        int result;
        result = this.x.hashCode();
        result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
        return result;
    }

    /**
     * Returns a string representing this instance, primarily for debugging
     * use.
     *
     * @return A string.
     */
    public String toString() {
        return "[" + getXValue() + ", " + getYValue() + "]";
    }

}