001    /* NavigationFilter.java --
002       Copyright (C) 2003, 2004 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.swing.text;
040    
041    public class NavigationFilter
042    {
043      public abstract static class FilterBypass
044      {
045        public FilterBypass()
046        {
047          // Do nothing here.
048        }
049    
050        public abstract Caret getCaret();
051        public abstract void moveDot(int dot, Position.Bias bias);
052        public abstract void setDot(int dot, Position.Bias bias);
053      }
054    
055      public NavigationFilter()
056      {
057        // Do nothing here.
058      }
059    
060      public void moveDot(NavigationFilter.FilterBypass fb, int dot,
061                          Position.Bias bias)
062      {
063        fb.moveDot(dot, bias);
064      }
065    
066      public void setDot(NavigationFilter.FilterBypass fb, int dot,
067                         Position.Bias bias)
068      {
069        fb.setDot(dot, bias);
070      }
071    
072      /**
073       * Returns the next visual position in the specified direction at which one
074       * would place a caret. The default implementation forwards to the text
075       * component's root view. Subclasses may wish to restrict that more.
076       *
077       * @param c the text component
078       * @param pos the current model position
079       * @param bias the bias of <code>pos</code>
080       * @param dir the direction, one of {@link javax.swing.SwingConstants#NORTH},
081       *        {@link javax.swing.SwingConstants#SOUTH},
082       *        {@link javax.swing.SwingConstants#WEST} or
083       *        {@link javax.swing.SwingConstants#EAST}
084       * @param retBias the bias of the returned position
085       *
086       * @return the next model location to place the caret
087       *
088       * @throws BadLocationException when <code>pos</code> is not a valid model
089       *         position
090       */
091      public int getNextVisualPositionFrom(JTextComponent c, int pos,
092                                           Position.Bias bias, int dir,
093                                           Position.Bias[] retBias)
094        throws BadLocationException
095      {
096        return c.getUI().getNextVisualPositionFrom(c, pos, bias, dir, retBias);
097      }
098    }