001    /* LineBreakMeasurer.java
002       Copyright (C) 2006 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 java.awt.font;
040    
041    import java.text.AttributedCharacterIterator;
042    import java.text.BreakIterator;
043    
044    public final class LineBreakMeasurer
045    {
046      private AttributedCharacterIterator text;
047      private int position;
048      private TextMeasurer tm; 
049      private int numChars;
050    
051      public LineBreakMeasurer(AttributedCharacterIterator text, 
052                               BreakIterator breakIter, FontRenderContext frc)
053      {
054        this( text, frc );
055      }
056    
057      public LineBreakMeasurer(AttributedCharacterIterator text, 
058                               FontRenderContext frc)
059      {
060        this.text = text;
061        position = 0;
062        numChars = text.getEndIndex();
063        tm = new TextMeasurer( text, frc );
064      }
065    
066      public void deleteChar(AttributedCharacterIterator newParagraph, 
067                             int deletePos)
068      {
069        tm.deleteChar( newParagraph, deletePos );
070        position = 0;
071      }
072    
073      public void insertChar(AttributedCharacterIterator newParagraph, 
074                             int insertPos)
075      {
076        tm.insertChar( newParagraph, insertPos );
077        position = 0;
078      }
079    
080      public TextLayout nextLayout(float wrappingWidth)
081      {
082        return nextLayout( wrappingWidth, numChars, false );
083      }
084    
085      public TextLayout nextLayout(float wrappingWidth, int offsetLimit, 
086                                   boolean requireNextWord)
087      {
088        int next = nextOffset( wrappingWidth, offsetLimit, requireNextWord );
089        TextLayout tl = tm.getLayout( position, next );
090        position = next;
091        return tl;
092      }
093    
094      public int nextOffset(float wrappingWidth)
095      {
096        return nextOffset( wrappingWidth, numChars, false );
097      }
098    
099      public int nextOffset(float wrappingWidth, int offsetLimit, 
100                            boolean requireNextWord)
101      {
102        int guessOffset = tm.getLineBreakIndex(position, wrappingWidth);
103        if( offsetLimit > numChars )
104          offsetLimit = numChars;
105    
106        if( guessOffset > offsetLimit )
107          {
108            text.setIndex( offsetLimit );
109            return offsetLimit;
110          }
111    
112        text.setIndex( guessOffset );
113    
114        // If we're on a breaking character, return directly
115        if( Character.isWhitespace( text.current() ) )
116          return guessOffset;
117    
118        // Otherwise jump forward or backward to the last such char.
119        if( !requireNextWord )
120          while( !Character.isWhitespace( text.previous() ) && 
121                 guessOffset > position )
122            guessOffset--; 
123        else
124          while( !Character.isWhitespace( text.next() ) && 
125                 guessOffset < offsetLimit )
126            guessOffset++;
127        
128        if( guessOffset > offsetLimit )
129          {
130            text.setIndex( offsetLimit );
131            return offsetLimit;
132          }
133    
134        text.setIndex( guessOffset );
135    
136        return guessOffset;
137      }
138    
139      public void setPosition(int newPosition)
140      {
141        position = newPosition;
142      }
143    
144      public int getPosition()
145      {
146        return position;
147      }
148    }
149