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 }