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