content: /* ===========================================================
   * 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.]
   *
   * -------------------------
   * ComparableObjectItem.java
   * -------------------------
   * (C) Copyright 2006-2008, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 19-Oct-2006 : New class, based on XYDataItem (DG);
   *
   */
  
  package org.jfree.data;
  
  import java.io.Serializable;
  
  import org.jfree.util.ObjectUtilities;
  
  /**
   * Represents one (Comparable, Object) data item for use in a
   * {@link ComparableObjectSeries}.
   *
   * @since 1.0.3
   */
  public class ComparableObjectItem implements Cloneable, Comparable,
          Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = 2751513470325494890L;
  
      /** The x-value. */
      private Comparable x;
  
      /** The y-value. */
      private Object obj;
  
      /**
       * Constructs a new data item.
       *
       * @param x  the x-value (<code>null</code> NOT permitted).
       * @param y  the y-value (<code>null</code> permitted).
       */
      public ComparableObjectItem(Comparable x, Object y) {
          if (x == null) {
              throw new IllegalArgumentException("Null 'x' argument.");
          }
          this.x = x;
          this.obj = y;
      }
  
      /**
       * Returns the x-value.
       *
       * @return The x-value (never <code>null</code>).
       */
      protected Comparable getComparable() {
          return this.x;
      }
  
      /**
       * Returns the y-value.
       *
       * @return The y-value (possibly <code>null</code>).
       */
      protected Object getObject() {
          return this.obj;
      }
  
      /**
       * 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</code> permitted).
       */
      protected void setObject(Object y) {
          this.obj = 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 ComparableObjectItem object
          // ---------------------------------------------------------
          if (o1 instanceof ComparableObjectItem) {
              ComparableObjectItem that = (ComparableObjectItem) o1;
              return this.x.compareTo(that.x);
          }
  
          // CASE 2 : Comparing to a general object
          // ---------------------------------------------
          else {
              // consider these 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</code>
       *             permitted).
       *
       * @return A boolean.
       */
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof ComparableObjectItem)) {
              return false;
          }
          ComparableObjectItem that = (ComparableObjectItem) obj;
          if (!this.x.equals(that.x)) {
              return false;
          }
          if (!ObjectUtilities.equal(this.obj, that.obj)) {
              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.obj != null ? this.obj.hashCode() : 0);
          return result;
      }
  
  }
  