J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package javax.swing.text.rtf; |
| 26 | |
| 27 | import java.io.*; |
| 28 | import java.lang.*; |
| 29 | |
| 30 | /** |
| 31 | * A generic superclass for streams which read and parse text |
| 32 | * consisting of runs of characters interspersed with occasional |
| 33 | * ``specials'' (formatting characters). |
| 34 | * |
| 35 | * <p> Most of the functionality |
| 36 | * of this class would be redundant except that the |
| 37 | * <code>ByteToChar</code> converters |
| 38 | * are suddenly private API. Presumably this class will disappear |
| 39 | * when the API is made public again. (sigh) That will also let us handle |
| 40 | * multibyte character sets... |
| 41 | * |
| 42 | * <P> A subclass should override at least <code>write(char)</code> |
| 43 | * and <code>writeSpecial(int)</code>. For efficiency's sake it's a |
| 44 | * good idea to override <code>write(String)</code> as well. The subclass' |
| 45 | * initializer may also install appropriate translation and specials tables. |
| 46 | * |
| 47 | * @see OutputStream |
| 48 | */ |
| 49 | abstract class AbstractFilter extends OutputStream |
| 50 | { |
| 51 | /** A table mapping bytes to characters */ |
| 52 | protected char translationTable[]; |
| 53 | /** A table indicating which byte values should be interpreted as |
| 54 | * characters and which should be treated as formatting codes */ |
| 55 | protected boolean specialsTable[]; |
| 56 | |
| 57 | /** A translation table which does ISO Latin-1 (trivial) */ |
| 58 | static final char latin1TranslationTable[]; |
| 59 | /** A specials table which indicates that no characters are special */ |
| 60 | static final boolean noSpecialsTable[]; |
| 61 | /** A specials table which indicates that all characters are special */ |
| 62 | static final boolean allSpecialsTable[]; |
| 63 | |
| 64 | static { |
| 65 | int i; |
| 66 | |
| 67 | noSpecialsTable = new boolean[256]; |
| 68 | for (i = 0; i < 256; i++) |
| 69 | noSpecialsTable[i] = false; |
| 70 | |
| 71 | allSpecialsTable = new boolean[256]; |
| 72 | for (i = 0; i < 256; i++) |
| 73 | allSpecialsTable[i] = true; |
| 74 | |
| 75 | latin1TranslationTable = new char[256]; |
| 76 | for (i = 0; i < 256; i++) |
| 77 | latin1TranslationTable[i] = (char)i; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * A convenience method that reads text from a FileInputStream |
| 82 | * and writes it to the receiver. |
| 83 | * The format in which the file |
| 84 | * is read is determined by the concrete subclass of |
| 85 | * AbstractFilter to which this method is sent. |
| 86 | * <p>This method does not close the receiver after reaching EOF on |
| 87 | * the input stream. |
| 88 | * The user must call <code>close()</code> to ensure that all |
| 89 | * data are processed. |
| 90 | * |
| 91 | * @param in An InputStream providing text. |
| 92 | */ |
| 93 | public void readFromStream(InputStream in) |
| 94 | throws IOException |
| 95 | { |
| 96 | byte buf[]; |
| 97 | int count; |
| 98 | |
| 99 | buf = new byte[16384]; |
| 100 | |
| 101 | while(true) { |
| 102 | count = in.read(buf); |
| 103 | if (count < 0) |
| 104 | break; |
| 105 | |
| 106 | this.write(buf, 0, count); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | public void readFromReader(Reader in) |
| 111 | throws IOException |
| 112 | { |
| 113 | char buf[]; |
| 114 | int count; |
| 115 | |
| 116 | buf = new char[2048]; |
| 117 | |
| 118 | while(true) { |
| 119 | count = in.read(buf); |
| 120 | if (count < 0) |
| 121 | break; |
| 122 | for (int i = 0; i < count; i++) { |
| 123 | this.write(buf[i]); |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | public AbstractFilter() |
| 129 | { |
| 130 | translationTable = latin1TranslationTable; |
| 131 | specialsTable = noSpecialsTable; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Implements the abstract method of OutputStream, of which this class |
| 136 | * is a subclass. |
| 137 | */ |
| 138 | public void write(int b) |
| 139 | throws IOException |
| 140 | { |
| 141 | if (b < 0) |
| 142 | b += 256; |
| 143 | if (specialsTable[b]) |
| 144 | writeSpecial(b); |
| 145 | else { |
| 146 | char ch = translationTable[b]; |
| 147 | if (ch != (char)0) |
| 148 | write(ch); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | /** |
| 153 | * Implements the buffer-at-a-time write method for greater |
| 154 | * efficiency. |
| 155 | * |
| 156 | * <p> <strong>PENDING:</strong> Does <code>write(byte[])</code> |
| 157 | * call <code>write(byte[], int, int)</code> or is it the other way |
| 158 | * around? |
| 159 | */ |
| 160 | public void write(byte[] buf, int off, int len) |
| 161 | throws IOException |
| 162 | { |
| 163 | StringBuffer accumulator = null; |
| 164 | while (len > 0) { |
| 165 | short b = (short)buf[off]; |
| 166 | |
| 167 | // stupid signed bytes |
| 168 | if (b < 0) |
| 169 | b += 256; |
| 170 | |
| 171 | if (specialsTable[b]) { |
| 172 | if (accumulator != null) { |
| 173 | write(accumulator.toString()); |
| 174 | accumulator = null; |
| 175 | } |
| 176 | writeSpecial(b); |
| 177 | } else { |
| 178 | char ch = translationTable[b]; |
| 179 | if (ch != (char)0) { |
| 180 | if (accumulator == null) |
| 181 | accumulator = new StringBuffer(); |
| 182 | accumulator.append(ch); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | len --; |
| 187 | off ++; |
| 188 | } |
| 189 | |
| 190 | if (accumulator != null) |
| 191 | write(accumulator.toString()); |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Hopefully, all subclasses will override this method to accept strings |
| 196 | * of text, but if they don't, AbstractFilter's implementation |
| 197 | * will spoon-feed them via <code>write(char)</code>. |
| 198 | * |
| 199 | * @param s The string of non-special characters written to the |
| 200 | * OutputStream. |
| 201 | */ |
| 202 | public void write(String s) |
| 203 | throws IOException |
| 204 | { |
| 205 | int index, length; |
| 206 | |
| 207 | length = s.length(); |
| 208 | for(index = 0; index < length; index ++) { |
| 209 | write(s.charAt(index)); |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Subclasses must provide an implementation of this method which |
| 215 | * accepts a single (non-special) character. |
| 216 | * |
| 217 | * @param ch The character written to the OutputStream. |
| 218 | */ |
| 219 | protected abstract void write(char ch) throws IOException; |
| 220 | |
| 221 | /** |
| 222 | * Subclasses must provide an implementation of this method which |
| 223 | * accepts a single special byte. No translation is performed |
| 224 | * on specials. |
| 225 | * |
| 226 | * @param b The byte written to the OutputStream. |
| 227 | */ |
| 228 | protected abstract void writeSpecial(int b) throws IOException; |
| 229 | } |