Source for javax.swing.LayoutFocusTraversalPolicy

   1: /* LayoutFocusTraversalPolicy.java --
   2:    Copyright (C) 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package javax.swing;
  40: 
  41: import java.awt.Component;
  42: import java.io.Serializable;
  43: import java.util.Comparator;
  44: 
  45: /**
  46:  * @author Graydon Hoare
  47:  * @author Michael Koch
  48:  * 
  49:  * @since 1.4
  50:  */
  51: public class LayoutFocusTraversalPolicy 
  52:   extends SortingFocusTraversalPolicy
  53:   implements Serializable
  54: {
  55:   private static class LayoutComparator
  56:     implements Comparator
  57:   {
  58:     public LayoutComparator()
  59:     {
  60:       // Do nothing here.
  61:     }
  62:     
  63:     public int compare(Object o1, Object o2)
  64:     {
  65:       Component comp1 = (Component) o1;
  66:       Component comp2 = (Component) o2;
  67: 
  68:       int x1 = comp1.getX();
  69:       int y1 = comp1.getY();
  70:       int x2 = comp2.getX();
  71:       int y2 = comp2.getY();
  72:       
  73:       if (x1 == x2 && y1 == y2)
  74:     return 0;
  75:       
  76:       if ((y1 < y2) || ((y1 == y2) && (x1 < x2)))
  77:     return -1;
  78: 
  79:       return 1;
  80:     }
  81:   }
  82: 
  83:   private static final long serialVersionUID = 4312146927238881442L;
  84:   
  85:   public LayoutFocusTraversalPolicy()
  86:   {
  87:     super(new LayoutComparator());
  88:   }
  89: }