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 
LineBreakMeasurer(AttributedCharacterIterator text, BreakIterator breakIter, FontRenderContext frc)51   public LineBreakMeasurer(AttributedCharacterIterator text,
52                            BreakIterator breakIter, FontRenderContext frc)
53   {
54     this( text, frc );
55   }
56 
LineBreakMeasurer(AttributedCharacterIterator text, FontRenderContext frc)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 
deleteChar(AttributedCharacterIterator newParagraph, int deletePos)66   public void deleteChar(AttributedCharacterIterator newParagraph,
67                          int deletePos)
68   {
69     tm.deleteChar( newParagraph, deletePos );
70     position = 0;
71   }
72 
insertChar(AttributedCharacterIterator newParagraph, int insertPos)73   public void insertChar(AttributedCharacterIterator newParagraph,
74                          int insertPos)
75   {
76     tm.insertChar( newParagraph, insertPos );
77     position = 0;
78   }
79 
nextLayout(float wrappingWidth)80   public TextLayout nextLayout(float wrappingWidth)
81   {
82     return nextLayout( wrappingWidth, numChars, false );
83   }
84 
nextLayout(float wrappingWidth, int offsetLimit, boolean requireNextWord)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 
nextOffset(float wrappingWidth)94   public int nextOffset(float wrappingWidth)
95   {
96     return nextOffset( wrappingWidth, numChars, false );
97   }
98 
nextOffset(float wrappingWidth, int offsetLimit, boolean requireNextWord)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 
setPosition(int newPosition)139   public void setPosition(int newPosition)
140   {
141     position = newPosition;
142   }
143 
getPosition()144   public int getPosition()
145   {
146     return position;
147   }
148 }
149