content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/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.]
   * 
   * --------------------
   * ClassComparator.java
   * --------------------
   * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner (taquera@sherito.org);
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: ClassComparator.java,v 1.5 2005/11/08 14:22:04 mungady Exp $
   *
   * Changes
   * -------
   * 02-May-2003 : Initial version
   */
  package org.jfree.xml.factory.objects;
  
  import java.io.Serializable;
  import java.util.Comparator;
  
  /**
   * The class comparator can be used to compare and sort classes and their
   * superclasses. The comparator is not able to compare classes which have
   * no relation...
   *
   * @author Thomas Morgner
   * @deprecated Moved to org.jfree.util
   */
  public class ClassComparator implements Comparator, Serializable {
  
      /**
       * Defaultconstructor.
       */
      public ClassComparator() {
          super();
      }
  
      /**
       * Compares its two arguments for order.  Returns a negative integer,
       * zero, or a positive integer as the first argument is less than, equal
       * to, or greater than the second.<p>
       * <P>
       * Note: throws ClassCastException if the arguments' types prevent them from
       * being compared by this Comparator.
       * And IllegalArgumentException if the classes share no relation.
       *
       * The implementor must ensure that <tt>sgn(compare(x, y)) ==
       * -sgn(compare(y, x))</tt> for all <tt>x</tt> and <tt>y</tt>.  (This
       * implies that <tt>compare(x, y)</tt> must throw an exception if and only
       * if <tt>compare(y, x)</tt> throws an exception.)<p>
       *
       * The implementor must also ensure that the relation is transitive:
       * <tt>((compare(x, y)&gt;0) &amp;&amp; (compare(y, z)&gt;0))</tt> implies
       * <tt>compare(x, z)&gt;0</tt>.<p>
       *
       * Finally, the implementer must ensure that <tt>compare(x, y)==0</tt>
       * implies that <tt>sgn(compare(x, z))==sgn(compare(y, z))</tt> for all
       * <tt>z</tt>.<p>
       *
       * It is generally the case, but <i>not</i> strictly required that
       * <tt>(compare(x, y)==0) == (x.equals(y))</tt>.  Generally speaking,
       * any comparator that violates this condition should clearly indicate
       * this fact.  The recommended language is "Note: this comparator
       * imposes orderings that are inconsistent with equals."
       *
       * @param o1 the first object to be compared.
       * @param o2 the second object to be compared.
       * @return a negative integer, zero, or a positive integer as the
       *         first argument is less than, equal to, or greater than the
       *         second.
       */
      public int compare(final Object o1, final Object o2) {
          final Class c1 = (Class) o1;
          final Class c2 = (Class) o2;
          if (c1.equals(o2)) {
              return 0;
          }
          if (c1.isAssignableFrom(c2)) {
              return -1;
          }
          else {
              if (!c2.isAssignableFrom(c2)) {
                  throw new IllegalArgumentException("The classes share no relation");
              }
              return 1;
          }
      }
  
      /**
       * Checks, whether the given classes are comparable. This method will
       * return true, if one of the classes is assignable from the other class.
       *
       * @param c1 the first class to compare
       * @param c2 the second class to compare
       * @return true, if the classes share a direct relation, false otherwise.
       */
      public boolean isComparable(final Class c1, final Class c2) {
          return (c1.isAssignableFrom(c2) || c2.isAssignableFrom(c1));
      }
  }
  