Source for java.awt.font.LineBreakMeasurer

   1: /* LineBreakMeasurer.java
   2:    Copyright (C) 2006 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 java.awt.font;
  40: 
  41: import java.text.AttributedCharacterIterator;
  42: import java.text.BreakIterator;
  43: 
  44: public final class LineBreakMeasurer
  45: {
  46:   private AttributedCharacterIterator text;
  47:   private int position;
  48:   private TextMeasurer tm;
  49:   private int numChars;
  50: 
  51:   public LineBreakMeasurer(AttributedCharacterIterator text,
  52:                            BreakIterator breakIter, FontRenderContext frc)
  53:   {
  54:     this( text, frc );
  55:   }
  56: 
  57:   public LineBreakMeasurer(AttributedCharacterIterator text,
  58:                            FontRenderContext frc)
  59:   {
  60:     this.text = text;
  61:     position = 0;
  62:     numChars = text.getEndIndex();
  63:     tm = new TextMeasurer( text, frc );
  64:   }
  65: 
  66:   public void deleteChar(AttributedCharacterIterator newParagraph,
  67:                          int deletePos)
  68:   {
  69:     tm.deleteChar( newParagraph, deletePos );
  70:     position = 0;
  71:   }
  72: 
  73:   public void insertChar(AttributedCharacterIterator newParagraph,
  74:                          int insertPos)
  75:   {
  76:     tm.insertChar( newParagraph, insertPos );
  77:     position = 0;
  78:   }
  79: 
  80:   public TextLayout nextLayout(float wrappingWidth)
  81:   {
  82:     return nextLayout( wrappingWidth, numChars, false );
  83:   }
  84: 
  85:   public TextLayout nextLayout(float wrappingWidth, int offsetLimit,
  86:                                boolean requireNextWord)
  87:   {
  88:     int next = nextOffset( wrappingWidth, offsetLimit, requireNextWord );
  89:     TextLayout tl = tm.getLayout( position, next );
  90:     position = next;
  91:     return tl;
  92:   }
  93: 
  94:   public int nextOffset(float wrappingWidth)
  95:   {
  96:     return nextOffset( wrappingWidth, numChars, false );
  97:   }
  98: 
  99:   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: }