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| 1 | /* | ||
| 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 3 | * | ||
| 4 | * This code is free software; you can redistribute it and/or modify it | ||
| 5 | * under the terms of the GNU General Public License version 2 only, as | ||
| 6 | * published by the Free Software Foundation. Oracle designates this | ||
| 7 | * particular file as subject to the "Classpath" exception as provided | ||
| 8 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 9 | * | ||
| 10 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 13 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 14 | * accompanied this code). | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU General Public License version | ||
| 17 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 18 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 19 | * | ||
| 20 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 21 | * or visit www.oracle.com if you need additional information or have any | ||
| 22 | * questions. | ||
| 23 | * | ||
| 24 | */ | ||
| 25 | |||
| 26 | /* | ||
| 27 | ******************************************************************************* | ||
| 28 | * | ||
| 29 | * Copyright (C) 1999-2003, International Business Machines | ||
| 30 | * Corporation and others. All Rights Reserved. | ||
| 31 | * | ||
| 32 | ******************************************************************************* | ||
| 33 | */ | ||
| 34 | |||
| 35 | package sun.font; | ||
| 36 | |||
| 37 | /** | ||
| 38 | * <code>ScriptRun</code> is used to find runs of characters in | ||
| 39 | * the same script, as defined in the <code>Script</code> class. | ||
| 40 | * It implements a simple iterator over an array of characters. | ||
| 41 | * The iterator will assign <code>COMMON</code> and <code>INHERITED</code> | ||
| 42 | * characters to the same script as the preceeding characters. If the | ||
| 43 | * COMMON and INHERITED characters are first, they will be assigned to | ||
| 44 | * the same script as the following characters. | ||
| 45 | * | ||
| 46 | * The iterator will try to match paired punctuation. If it sees an | ||
| 47 | * opening punctuation character, it will remember the script that | ||
| 48 | * was assigned to that character, and assign the same script to the | ||
| 49 | * matching closing punctuation. | ||
| 50 | * | ||
| 51 | * No attempt is made to combine related scripts into a single run. In | ||
| 52 | * particular, Hiragana, Katakana, and Han characters will appear in seperate | ||
| 53 | * runs. | ||
| 54 | |||
| 55 | * Here is an example of how to iterate over script runs: | ||
| 56 | * <pre> | ||
| 57 | * void printScriptRuns(char[] text) | ||
| 58 | * { | ||
| 59 | * ScriptRun scriptRun = new ScriptRun(text, 0, text.length); | ||
| 60 | * | ||
| 61 | * while (scriptRun.next()) { | ||
| 62 | * int start = scriptRun.getScriptStart(); | ||
| 63 | * int limit = scriptRun.getScriptLimit(); | ||
| 64 | * int script = scriptRun.getScriptCode(); | ||
| 65 | * | ||
| 66 | * System.out.println("Script \"" + Script.getName(script) + "\" from " + | ||
| 67 | * start + " to " + limit + "."); | ||
| 68 | * } | ||
| 69 | * } | ||
| 70 | * </pre> | ||
| 71 | * | ||
| 72 | */ | ||
| 73 | public final class ScriptRun | ||
| 74 | { | ||
| 75 | private char[] text; // fixed once set by constructor | ||
| 76 | private int textStart; | ||
| 77 | private int textLimit; | ||
| 78 | |||
| 79 | private int scriptStart; // change during iteration | ||
| 80 | private int scriptLimit; | ||
| 81 | private int scriptCode; | ||
| 82 | |||
| 83 | private int stack[]; // stack used to handle paired punctuation if encountered | ||
| 84 | private int parenSP; | ||
| 85 | |||
| 86 | public ScriptRun() { | ||
| 87 | // must call init later or we die. | ||
| 88 | } | ||
| 89 | |||
| 90 | /** | ||
| 91 | * Construct a <code>ScriptRun</code> object which iterates over a subrange | ||
| 92 | * of the given characetrs. | ||
| 93 | * | ||
| 94 | * @param chars the array of characters over which to iterate. | ||
| 95 | * @param start the index of the first character over which to iterate | ||
| 96 | * @param count the number of characters over which to iterate | ||
| 97 | */ | ||
| 98 | public ScriptRun(char[] chars, int start, int count) | ||
| 99 | { | ||
| 100 | init(chars, start, count); | ||
| 101 | } | ||
| 102 | |||
| 103 | public void init(char[] chars, int start, int count) | ||
| 104 | { | ||
| 105 | if (chars == null || start < 0 || count < 0 || count > chars.length - start) { | ||
| 106 | throw new IllegalArgumentException(); | ||
| 107 | } | ||
| 108 | |||
| 109 | text = chars; | ||
| 110 | textStart = start; | ||
| 111 | textLimit = start + count; | ||
| 112 | |||
| 113 | scriptStart = textStart; | ||
| 114 | scriptLimit = textStart; | ||
| 115 | scriptCode = Script.INVALID_CODE; | ||
| 116 | parenSP = 0; | ||
| 117 | } | ||
| 118 | |||
| 119 | /** | ||
| 120 | * Get the starting index of the current script run. | ||
| 121 | * | ||
| 122 | * @return the index of the first character in the current script run. | ||
| 123 | */ | ||
| 124 | public final int getScriptStart() { | ||
| 125 | return scriptStart; | ||
| 126 | } | ||
| 127 | |||
| 128 | /** | ||
| 129 | * Get the index of the first character after the current script run. | ||
| 130 | * | ||
| 131 | * @return the index of the first character after the current script run. | ||
| 132 | */ | ||
| 133 | public final int getScriptLimit() { | ||
| 134 | return scriptLimit; | ||
| 135 | } | ||
| 136 | |||
| 137 | /** | ||
| 138 | * Get the script code for the script of the current script run. | ||
| 139 | * | ||
| 140 | * @return the script code for the script of the current script run. | ||
| 141 | * @see #Script | ||
| 142 | */ | ||
| 143 | public final int getScriptCode() { | ||
| 144 | return scriptCode; | ||
| 145 | } | ||
| 146 | |||
| 147 | /** | ||
| 148 | * Find the next script run. Returns <code>false</code> if there | ||
| 149 | * isn't another run, returns <code>true</code> if there is. | ||
| 150 | * | ||
| 151 | * @return <code>false</code> if there isn't another run, <code>true</code> if there is. | ||
| 152 | */ | ||
| 153 | public final boolean next() { | ||
| 154 | int startSP = parenSP; // used to find the first new open character | ||
| 155 | |||
| 156 | // if we've fallen off the end of the text, we're done | ||
| 157 | if (scriptLimit >= textLimit) { | ||
| 158 | return false; | ||
| 159 | } | ||
| 160 | |||
| 161 | scriptCode = Script.COMMON; | ||
| 162 | scriptStart = scriptLimit; | ||
| 163 | |||
| 164 | int ch; | ||
| 165 | |||
| 166 | while ((ch = nextCodePoint()) != DONE) { | ||
| 167 | int sc = ScriptRunData.getScript(ch); | ||
| 168 | int pairIndex = sc == Script.COMMON ? getPairIndex(ch) : -1; | ||
| 169 | |||
| 170 | // Paired character handling: | ||
| 171 | // | ||
| 172 | // if it's an open character, push it onto the stack. | ||
| 173 | // if it's a close character, find the matching open on the | ||
| 174 | // stack, and use that script code. Any non-matching open | ||
| 175 | // characters above it on the stack will be popped. | ||
| 176 | if (pairIndex >= 0) { | ||
| 177 | if ((pairIndex & 1) == 0) { | ||
| 178 | if (stack == null) { | ||
| 179 | stack = new int[32]; | ||
| 180 | } else if (parenSP == stack.length) { | ||
| 181 | int[] newstack = new int[stack.length + 32]; | ||
| 182 | System.arraycopy(stack, 0, newstack, 0, stack.length); | ||
| 183 | stack = newstack; | ||
| 184 | } | ||
| 185 | |||
| 186 | stack[parenSP++] = pairIndex; | ||
| 187 | stack[parenSP++] = scriptCode; | ||
| 188 | } else if (parenSP > 0) { | ||
| 189 | int pi = pairIndex & ~1; | ||
| 190 | |||
| 191 | while ((parenSP -= 2) >= 0 && stack[parenSP] != pi); | ||
| 192 | |||
| 193 | if (parenSP >= 0) { | ||
| 194 | sc = stack[parenSP+1]; | ||
| 195 | } else { | ||
| 196 | parenSP = 0; | ||
| 197 | } | ||
| 198 | if (parenSP < startSP) { | ||
| 199 | startSP = parenSP; | ||
| 200 | } | ||
| 201 | } | ||
| 202 | } | ||
| 203 | |||
| 204 | if (sameScript(scriptCode, sc)) { | ||
| 205 | if (scriptCode <= Script.INHERITED && sc > Script.INHERITED) { | ||
| 206 | scriptCode = sc; | ||
| 207 | |||
| 208 | // now that we have a final script code, fix any open | ||
| 209 | // characters we pushed before we knew the script code. | ||
| 210 | while (startSP < parenSP) { | ||
| 211 | stack[startSP+1] = scriptCode; | ||
| 212 | startSP += 2; | ||
| 213 | } | ||
| 214 | } | ||
| 215 | |||
| 216 | // if this character is a close paired character, | ||
| 217 | // pop it from the stack | ||
| 218 | if (pairIndex > 0 && (pairIndex & 1) != 0 && parenSP > 0) { | ||
| 219 | parenSP -= 2; | ||
| 220 | } | ||
| 221 | } else { | ||
| 222 | // We've just seen the first character of | ||
| 223 | // the next run. Back over it so we'll see | ||
| 224 | // it again the next time. | ||
| 225 | pushback(ch); | ||
| 226 | |||
| 227 | // we're outta here | ||
| 228 | break; | ||
| 229 | } | ||
| 230 | } | ||
| 231 | |||
| 232 | return true; | ||
| 233 | } | ||
| 234 | |||
| 235 | static final int SURROGATE_START = 0x10000; | ||
| 236 | static final int LEAD_START = 0xd800; | ||
| 237 | static final int LEAD_LIMIT = 0xdc00; | ||
| 238 | static final int TAIL_START = 0xdc00; | ||
| 239 | static final int TAIL_LIMIT = 0xe000; | ||
| 240 | static final int LEAD_SURROGATE_SHIFT = 10; | ||
| 241 | static final int SURROGATE_OFFSET = SURROGATE_START - (LEAD_START << LEAD_SURROGATE_SHIFT) - TAIL_START; | ||
| 242 | |||
| 243 | static final int DONE = -1; | ||
| 244 | |||
| 245 | private final int nextCodePoint() { | ||
| 246 | if (scriptLimit >= textLimit) { | ||
| 247 | return DONE; | ||
| 248 | } | ||
| 249 | int ch = text[scriptLimit++]; | ||
| 250 | if (ch >= LEAD_START && ch < LEAD_LIMIT && scriptLimit < textLimit) { | ||
| 251 | int nch = text[scriptLimit]; | ||
| 252 | if (nch >= TAIL_START && nch < TAIL_LIMIT) { | ||
| 253 | ++scriptLimit; | ||
| 254 | ch = (ch << LEAD_SURROGATE_SHIFT) + nch + SURROGATE_OFFSET; | ||
| 255 | } | ||
| 256 | } | ||
| 257 | return ch; | ||
| 258 | } | ||
| 259 | |||
| 260 | private final void pushback(int ch) { | ||
| 261 | if (ch >= 0) { | ||
| 262 | if (ch >= 0x10000) { | ||
| 263 | scriptLimit -= 2; | ||
| 264 | } else { | ||
| 265 | scriptLimit -= 1; | ||
| 266 | } | ||
| 267 | } | ||
| 268 | } | ||
| 269 | |||
| 270 | /** | ||
| 271 | * Compare two script codes to see if they are in the same script. If one script is | ||
| 272 | * a strong script, and the other is INHERITED or COMMON, it will compare equal. | ||
| 273 | * | ||
| 274 | * @param scriptOne one of the script codes. | ||
| 275 | * @param scriptTwo the other script code. | ||
| 276 | * @return <code>true</code> if the two scripts are the same. | ||
| 277 | * @see com.ibm.icu.lang.Script | ||
| 278 | */ | ||
| 279 | private static boolean sameScript(int scriptOne, int scriptTwo) { | ||
| 280 | return scriptOne == scriptTwo || scriptOne <= Script.INHERITED || scriptTwo <= Script.INHERITED; | ||
| 281 | } | ||
| 282 | |||
| 283 | /** | ||
| 284 | * Find the highest bit that's set in a word. Uses a binary search through | ||
| 285 | * the bits. | ||
| 286 | * | ||
| 287 | * @param n the word in which to find the highest bit that's set. | ||
| 288 | * @return the bit number (counting from the low order bit) of the highest bit. | ||
| 289 | */ | ||
| 290 | private static final byte highBit(int n) | ||
| 291 | { | ||
| 292 | if (n <= 0) { | ||
| 293 | return -32; | ||
| 294 | } | ||
| 295 | |||
| 296 | byte bit = 0; | ||
| 297 | |||
| 298 | if (n >= 1 << 16) { | ||
| 299 | n >>= 16; | ||
| 300 | bit += 16; | ||
| 301 | } | ||
| 302 | |||
| 303 | if (n >= 1 << 8) { | ||
| 304 | n >>= 8; | ||
| 305 | bit += 8; | ||
| 306 | } | ||
| 307 | |||
| 308 | if (n >= 1 << 4) { | ||
| 309 | n >>= 4; | ||
| 310 | bit += 4; | ||
| 311 | } | ||
| 312 | |||
| 313 | if (n >= 1 << 2) { | ||
| 314 | n >>= 2; | ||
| 315 | bit += 2; | ||
| 316 | } | ||
| 317 | |||
| 318 | if (n >= 1 << 1) { | ||
| 319 | n >>= 1; | ||
| 320 | bit += 1; | ||
| 321 | } | ||
| 322 | |||
| 323 | return bit; | ||
| 324 | } | ||
| 325 | |||
| 326 | /** | ||
| 327 | * Search the pairedChars array for the given character. | ||
| 328 | * | ||
| 329 | * @param ch the character for which to search. | ||
| 330 | * @return the index of the character in the table, or -1 if it's not there. | ||
| 331 | */ | ||
| 332 | private static int getPairIndex(int ch) | ||
| 333 | { | ||
| 334 | int probe = pairedCharPower; | ||
| 335 | int index = 0; | ||
| 336 | |||
| 337 | if (ch >= pairedChars[pairedCharExtra]) { | ||
| 338 | index = pairedCharExtra; | ||
| 339 | } | ||
| 340 | |||
| 341 | while (probe > (1 << 0)) { | ||
| 342 | probe >>= 1; | ||
| 343 | |||
| 344 | if (ch >= pairedChars[index + probe]) { | ||
| 345 | index += probe; | ||
| 346 | } | ||
| 347 | } | ||
| 348 | |||
| 349 | if (pairedChars[index] != ch) { | ||
| 350 | index = -1; | ||
| 351 | } | ||
| 352 | |||
| 353 | return index; | ||
| 354 | } | ||
| 355 | |||
| 356 | // all common | ||
| 357 | private static int pairedChars[] = { | ||
| 358 | 0x0028, 0x0029, // ascii paired punctuation // common | ||
| 359 | 0x003c, 0x003e, // common | ||
| 360 | 0x005b, 0x005d, // common | ||
| 361 | 0x007b, 0x007d, // common | ||
| 362 | 0x00ab, 0x00bb, // guillemets // common | ||
| 363 | 0x2018, 0x2019, // general punctuation // common | ||
| 364 | 0x201c, 0x201d, // common | ||
| 365 | 0x2039, 0x203a, // common | ||
| 366 | 0x3008, 0x3009, // chinese paired punctuation // common | ||
| 367 | 0x300a, 0x300b, | ||
| 368 | 0x300c, 0x300d, | ||
| 369 | 0x300e, 0x300f, | ||
| 370 | 0x3010, 0x3011, | ||
| 371 | 0x3014, 0x3015, | ||
| 372 | 0x3016, 0x3017, | ||
| 373 | 0x3018, 0x3019, | ||
| 374 | 0x301a, 0x301b | ||
| 375 | }; | ||
| 376 | |||
| 377 | private static final int pairedCharPower = 1 << highBit(pairedChars.length); | ||
| 378 | private static final int pairedCharExtra = pairedChars.length - pairedCharPower; | ||
| 379 | |||
| 380 | } | ||