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.AttributedString;
043    import java.text.BreakIterator;
044    import java.awt.Shape;
045    
046    public final class LineBreakMeasurer
047    {
048      private AttributedCharacterIterator text;
049      private int position;
050      private TextMeasurer tm; 
051      private int numChars;
052    
053      public LineBreakMeasurer(AttributedCharacterIterator text, 
054                               BreakIterator breakIter, FontRenderContext frc)
055      {
056        this( text, frc );
057      }
058    
059      public LineBreakMeasurer(AttributedCharacterIterator text, 
060                               FontRenderContext frc)
061      {
062        this.text = text;
063        position = 0;
064        numChars = text.getEndIndex();
065        tm = new TextMeasurer( text, frc );
066      }
067    
068      public void deleteChar(AttributedCharacterIterator newParagraph, 
069                             int deletePos)
070      {
071        tm.deleteChar( newParagraph, deletePos );
072        position = 0;
073      }
074    
075      public void insertChar(AttributedCharacterIterator newParagraph, 
076                             int insertPos)
077      {
078        tm.insertChar( newParagraph, insertPos );
079        position = 0;
080      }
081    
082      public TextLayout nextLayout(float wrappingWidth)
083      {
084        return nextLayout( wrappingWidth, numChars, false );
085      }
086    
087      public TextLayout nextLayout(float wrappingWidth, int offsetLimit, 
088                                   boolean requireNextWord)
089      {
090        int next = nextOffset( wrappingWidth, offsetLimit, requireNextWord );
091        TextLayout tl = tm.getLayout( position, next );
092        position = next;
093        return tl;
094      }
095    
096      public int nextOffset(float wrappingWidth)
097      {
098        return nextOffset( wrappingWidth, numChars, false );
099      }
100    
101      public int nextOffset(float wrappingWidth, int offsetLimit, 
102                            boolean requireNextWord)
103      {
104        int guessOffset = tm.getLineBreakIndex(position, wrappingWidth);
105        if( offsetLimit > numChars )
106          offsetLimit = numChars;
107    
108        if( guessOffset > offsetLimit )
109          {
110            text.setIndex( offsetLimit );
111            return offsetLimit;
112          }
113    
114        text.setIndex( guessOffset );
115    
116        // If we're on a breaking character, return directly
117        if( Character.isWhitespace( text.current() ) )
118          return guessOffset;
119    
120        // Otherwise jump forward or backward to the last such char.
121        if( !requireNextWord )
122          while( !Character.isWhitespace( text.previous() ) && 
123                 guessOffset > position )
124            guessOffset--; 
125        else
126          while( !Character.isWhitespace( text.next() ) && 
127                 guessOffset < offsetLimit )
128            guessOffset++;
129        
130        if( guessOffset > offsetLimit )
131          {
132            text.setIndex( offsetLimit );
133            return offsetLimit;
134          }
135    
136        text.setIndex( guessOffset );
137    
138        return guessOffset;
139      }
140    
141      public void setPosition(int newPosition)
142      {
143        position = newPosition;
144      }
145    
146      public int getPosition()
147      {
148        return position;
149      }
150    }
151