001/* LineBreakMeasurer.java 002 Copyright (C) 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.awt.font; 040 041import java.text.AttributedCharacterIterator; 042import java.text.BreakIterator; 043 044public 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}