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.]
   * 
   * -------------
   * RectangleEdge
   * -------------
   * (C) Copyright 2003-2005, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * $Id: RectangleEdge.java,v 1.4 2005/10/18 13:18:34 mungady Exp $
   *
   * Changes:
   * --------
   * 14-Jul-2003 (DG);
   * 
   */
  
  package org.jfree.ui;
  
  import java.awt.geom.Rectangle2D;
  import java.io.ObjectStreamException;
  import java.io.Serializable;
  
  /**
   * Used to indicate the edge of a rectangle.
   *
   * @author David Gilbert
   */
  public final class RectangleEdge implements Serializable {
  
      /** For serialization. */
      private static final long serialVersionUID = -7400988293691093548L;
      
      /** Top. */
      public static final RectangleEdge TOP 
          = new RectangleEdge("RectangleEdge.TOP");
  
      /** Bottom. */
      public static final RectangleEdge BOTTOM 
          = new RectangleEdge("RectangleEdge.BOTTOM");
  
      /** Left. */
      public static final RectangleEdge LEFT 
          = new RectangleEdge("RectangleEdge.LEFT");
  
      /** Right. */
      public static final RectangleEdge RIGHT 
          = new RectangleEdge("RectangleEdge.RIGHT");
  
      /** The name. */
      private String name;
  
      /**
       * Private constructor.
       *
       * @param name  the name.
       */
      private RectangleEdge(final String name) {
          this.name = name;
      }
  
      /**
       * Returns a string representing the object.
       *
       * @return The string.
       */
      public String toString() {
          return this.name;
      }
  
      /**
       * Returns <code>true</code> if this object is equal to the specified 
       * object, and <code>false</code> otherwise.
       *
       * @param o  the other object.
       *
       * @return A boolean.
       */
      public boolean equals(final Object o) {
  
          if (this == o) {
              return true;
          }
          if (!(o instanceof RectangleEdge)) {
              return false;
          }
  
          final RectangleEdge order = (RectangleEdge) o;
          if (!this.name.equals(order.name)) {
              return false;
          }
  
          return true;
  
      }
  
      /**
       * Returns a hash code value for the object.
       *
       * @return the hashcode
       */
      public int hashCode() {
          return this.name.hashCode();
      }
  
      /**
       * Returns <code>true</code> if the edge is <code>TOP</code> or 
       * <code>BOTTOM</code>, and <code>false</code> otherwise.
       * 
       * @param edge  the edge.
       * 
       * @return A boolean.
       */
      public static boolean isTopOrBottom(final RectangleEdge edge) {
          return (edge == RectangleEdge.TOP || edge == RectangleEdge.BOTTOM);    
      }
      
      /**
       * Returns <code>true</code> if the edge is <code>LEFT</code> or 
       * <code>RIGHT</code>, and <code>false</code> otherwise.
       * 
       * @param edge  the edge.
       * 
       * @return A boolean.
       */
      public static boolean isLeftOrRight(final RectangleEdge edge) {
          return (edge == RectangleEdge.LEFT || edge == RectangleEdge.RIGHT);    
      }
  
      /**
       * Returns the opposite edge.
       * 
       * @param edge  an edge.
       * 
       * @return The opposite edge.
       */
      public static RectangleEdge opposite(final RectangleEdge edge) {
          RectangleEdge result = null;
          if (edge == RectangleEdge.TOP) {
              result = RectangleEdge.BOTTOM;
          }
          else if (edge == RectangleEdge.BOTTOM) {
              result = RectangleEdge.TOP;
          }
          else if (edge == RectangleEdge.LEFT) {
              result = RectangleEdge.RIGHT;
          }
          else if (edge == RectangleEdge.RIGHT) {
              result = RectangleEdge.LEFT;
          }
          return result;
      }
      
      /**
       * Returns the x or y coordinate of the specified edge.
       * 
       * @param rectangle  the rectangle.
       * @param edge  the edge.
       * 
       * @return The coordinate.
       */
      public static double coordinate(final Rectangle2D rectangle, 
                                      final RectangleEdge edge) {
          double result = 0.0;
          if (edge == RectangleEdge.TOP) {
              result = rectangle.getMinY();
          }
          else if (edge == RectangleEdge.BOTTOM) {
              result = rectangle.getMaxY();
          }
          else if (edge == RectangleEdge.LEFT) {
              result = rectangle.getMinX();
          }
          else if (edge == RectangleEdge.RIGHT) {
              result = rectangle.getMaxX();
          }
          return result;
      }
      
      /**
       * Ensures that serialization returns the unique instances.
       * 
       * @return The object.
       * 
       * @throws ObjectStreamException if there is a problem.
       */
      private Object readResolve() throws ObjectStreamException {
          RectangleEdge result = null;
          if (this.equals(RectangleEdge.TOP)) {
              result = RectangleEdge.TOP;
          }
          else if (this.equals(RectangleEdge.BOTTOM)) {
              result = RectangleEdge.BOTTOM;
          }
          else if (this.equals(RectangleEdge.LEFT)) {
              result = RectangleEdge.LEFT;
          }
          else if (this.equals(RectangleEdge.RIGHT)) {
              result = RectangleEdge.RIGHT;
          }
          return result;
      }
      
  }
  