1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 package com.android.inputmethod.latin; 18 19 import android.content.Context; 20 import android.text.TextUtils; 21 import android.util.Log; 22 23 import com.android.inputmethod.keyboard.Keyboard; 24 import com.android.inputmethod.keyboard.ProximityInfo; 25 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo; 26 27 import java.io.File; 28 import java.util.ArrayList; 29 import java.util.HashSet; 30 import java.util.Locale; 31 import java.util.concurrent.ConcurrentHashMap; 32 33 /** 34 * This class loads a dictionary and provides a list of suggestions for a given sequence of 35 * characters. This includes corrections and completions. 36 */ 37 public class Suggest implements Dictionary.WordCallback { 38 public static final String TAG = Suggest.class.getSimpleName(); 39 40 public static final int APPROX_MAX_WORD_LENGTH = 32; 41 42 public static final int CORRECTION_NONE = 0; 43 public static final int CORRECTION_FULL = 1; 44 public static final int CORRECTION_FULL_BIGRAM = 2; 45 46 // It seems the following values are only used for logging. 47 public static final int DIC_USER_TYPED = 0; 48 public static final int DIC_MAIN = 1; 49 public static final int DIC_USER = 2; 50 public static final int DIC_USER_HISTORY = 3; 51 public static final int DIC_CONTACTS = 4; 52 public static final int DIC_WHITELIST = 6; 53 // If you add a type of dictionary, increment DIC_TYPE_LAST_ID 54 // TODO: this value seems unused. Remove it? 55 public static final int DIC_TYPE_LAST_ID = 6; 56 public static final String DICT_KEY_MAIN = "main"; 57 public static final String DICT_KEY_CONTACTS = "contacts"; 58 // User dictionary, the system-managed one. 59 public static final String DICT_KEY_USER = "user"; 60 // User history dictionary for the unigram map, internal to LatinIME 61 public static final String DICT_KEY_USER_HISTORY_UNIGRAM = "history_unigram"; 62 // User history dictionary for the bigram map, internal to LatinIME 63 public static final String DICT_KEY_USER_HISTORY_BIGRAM = "history_bigram"; 64 public static final String DICT_KEY_WHITELIST ="whitelist"; 65 66 private static final boolean DBG = LatinImeLogger.sDBG; 67 68 private boolean mHasMainDictionary; 69 private Dictionary mContactsDict; 70 private WhitelistDictionary mWhiteListDictionary; 71 private final ConcurrentHashMap<String, Dictionary> mUnigramDictionaries = 72 new ConcurrentHashMap<String, Dictionary>(); 73 private final ConcurrentHashMap<String, Dictionary> mBigramDictionaries = 74 new ConcurrentHashMap<String, Dictionary>(); 75 76 private int mPrefMaxSuggestions = 18; 77 78 private static final int PREF_MAX_BIGRAMS = 60; 79 80 private float mAutoCorrectionThreshold; 81 82 private ArrayList<SuggestedWordInfo> mSuggestions = new ArrayList<SuggestedWordInfo>(); 83 private ArrayList<SuggestedWordInfo> mBigramSuggestions = new ArrayList<SuggestedWordInfo>(); 84 private CharSequence mConsideredWord; 85 86 // TODO: Remove these member variables by passing more context to addWord() callback method 87 private boolean mIsFirstCharCapitalized; 88 private boolean mIsAllUpperCase; 89 private int mTrailingSingleQuotesCount; 90 91 private static final int MINIMUM_SAFETY_NET_CHAR_LENGTH = 4; 92 93 public Suggest(final Context context, final Locale locale) { 94 initAsynchronously(context, locale); 95 } 96 97 /* package for test */ Suggest(final Context context, final File dictionary, 98 final long startOffset, final long length, final Locale locale) { 99 final Dictionary mainDict = DictionaryFactory.createDictionaryForTest(context, dictionary, 100 startOffset, length /* useFullEditDistance */, false, locale); 101 mHasMainDictionary = null != mainDict; 102 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, mainDict); 103 addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, mainDict); 104 initWhitelistAndAutocorrectAndPool(context, locale); 105 } 106 107 private void initWhitelistAndAutocorrectAndPool(final Context context, final Locale locale) { 108 mWhiteListDictionary = new WhitelistDictionary(context, locale); 109 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_WHITELIST, mWhiteListDictionary); 110 } 111 112 private void initAsynchronously(final Context context, final Locale locale) { 113 resetMainDict(context, locale); 114 115 // TODO: read the whitelist and init the pool asynchronously too. 116 // initPool should be done asynchronously now that the pool is thread-safe. 117 initWhitelistAndAutocorrectAndPool(context, locale); 118 } 119 120 private static void addOrReplaceDictionary( 121 final ConcurrentHashMap<String, Dictionary> dictionaries, 122 final String key, final Dictionary dict) { 123 final Dictionary oldDict = (dict == null) 124 ? dictionaries.remove(key) 125 : dictionaries.put(key, dict); 126 if (oldDict != null && dict != oldDict) { 127 oldDict.close(); 128 } 129 } 130 131 public void resetMainDict(final Context context, final Locale locale) { 132 mHasMainDictionary = false; 133 new Thread("InitializeBinaryDictionary") { 134 @Override 135 public void run() { 136 final DictionaryCollection newMainDict = 137 DictionaryFactory.createMainDictionaryFromManager(context, locale); 138 mHasMainDictionary = null != newMainDict && !newMainDict.isEmpty(); 139 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, newMainDict); 140 addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, newMainDict); 141 } 142 }.start(); 143 } 144 145 // The main dictionary could have been loaded asynchronously. Don't cache the return value 146 // of this method. 147 public boolean hasMainDictionary() { 148 return mHasMainDictionary; 149 } 150 151 public Dictionary getContactsDictionary() { 152 return mContactsDict; 153 } 154 155 public ConcurrentHashMap<String, Dictionary> getUnigramDictionaries() { 156 return mUnigramDictionaries; 157 } 158 159 public static int getApproxMaxWordLength() { 160 return APPROX_MAX_WORD_LENGTH; 161 } 162 163 /** 164 * Sets an optional user dictionary resource to be loaded. The user dictionary is consulted 165 * before the main dictionary, if set. This refers to the system-managed user dictionary. 166 */ 167 public void setUserDictionary(Dictionary userDictionary) { 168 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER, userDictionary); 169 } 170 171 /** 172 * Sets an optional contacts dictionary resource to be loaded. It is also possible to remove 173 * the contacts dictionary by passing null to this method. In this case no contacts dictionary 174 * won't be used. 175 */ 176 public void setContactsDictionary(Dictionary contactsDictionary) { 177 mContactsDict = contactsDictionary; 178 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary); 179 addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary); 180 } 181 182 public void setUserHistoryDictionary(Dictionary userHistoryDictionary) { 183 addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER_HISTORY_UNIGRAM, 184 userHistoryDictionary); 185 addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_USER_HISTORY_BIGRAM, 186 userHistoryDictionary); 187 } 188 189 public void setAutoCorrectionThreshold(float threshold) { 190 mAutoCorrectionThreshold = threshold; 191 } 192 193 private static CharSequence capitalizeWord(final boolean all, final boolean first, 194 final CharSequence word) { 195 if (TextUtils.isEmpty(word) || !(all || first)) return word; 196 final int wordLength = word.length(); 197 final StringBuilder sb = new StringBuilder(getApproxMaxWordLength()); 198 // TODO: Must pay attention to locale when changing case. 199 if (all) { 200 sb.append(word.toString().toUpperCase()); 201 } else if (first) { 202 sb.append(Character.toUpperCase(word.charAt(0))); 203 if (wordLength > 1) { 204 sb.append(word.subSequence(1, wordLength)); 205 } 206 } 207 return sb; 208 } 209 210 protected void addBigramToSuggestions(SuggestedWordInfo bigram) { 211 mSuggestions.add(bigram); 212 } 213 214 private static final WordComposer sEmptyWordComposer = new WordComposer(); 215 public SuggestedWords getBigramPredictions(CharSequence prevWordForBigram) { 216 LatinImeLogger.onStartSuggestion(prevWordForBigram); 217 mIsFirstCharCapitalized = false; 218 mIsAllUpperCase = false; 219 mTrailingSingleQuotesCount = 0; 220 mSuggestions = new ArrayList<SuggestedWordInfo>(mPrefMaxSuggestions); 221 222 // Treating USER_TYPED as UNIGRAM suggestion for logging now. 223 LatinImeLogger.onAddSuggestedWord("", Suggest.DIC_USER_TYPED, Dictionary.UNIGRAM); 224 mConsideredWord = ""; 225 226 mBigramSuggestions = new ArrayList<SuggestedWordInfo>(PREF_MAX_BIGRAMS); 227 228 getAllBigrams(prevWordForBigram, sEmptyWordComposer); 229 230 // Nothing entered: return all bigrams for the previous word 231 int insertCount = Math.min(mBigramSuggestions.size(), mPrefMaxSuggestions); 232 for (int i = 0; i < insertCount; ++i) { 233 addBigramToSuggestions(mBigramSuggestions.get(i)); 234 } 235 236 SuggestedWordInfo.removeDups(mSuggestions); 237 238 return new SuggestedWords(mSuggestions, 239 false /* typedWordValid */, 240 false /* hasAutoCorrectionCandidate */, 241 false /* allowsToBeAutoCorrected */, 242 false /* isPunctuationSuggestions */, 243 false /* isObsoleteSuggestions */, 244 true /* isPrediction */); 245 } 246 247 // TODO: cleanup dictionaries looking up and suggestions building with SuggestedWords.Builder 248 public SuggestedWords getSuggestedWords( 249 final WordComposer wordComposer, CharSequence prevWordForBigram, 250 final ProximityInfo proximityInfo, final int correctionMode) { 251 LatinImeLogger.onStartSuggestion(prevWordForBigram); 252 mIsFirstCharCapitalized = wordComposer.isFirstCharCapitalized(); 253 mIsAllUpperCase = wordComposer.isAllUpperCase(); 254 mTrailingSingleQuotesCount = wordComposer.trailingSingleQuotesCount(); 255 mSuggestions = new ArrayList<SuggestedWordInfo>(mPrefMaxSuggestions); 256 257 final String typedWord = wordComposer.getTypedWord(); 258 final String consideredWord = mTrailingSingleQuotesCount > 0 259 ? typedWord.substring(0, typedWord.length() - mTrailingSingleQuotesCount) 260 : typedWord; 261 // Treating USER_TYPED as UNIGRAM suggestion for logging now. 262 LatinImeLogger.onAddSuggestedWord(typedWord, Suggest.DIC_USER_TYPED, Dictionary.UNIGRAM); 263 mConsideredWord = consideredWord; 264 265 if (wordComposer.size() <= 1 && (correctionMode == CORRECTION_FULL_BIGRAM)) { 266 // At first character typed, search only the bigrams 267 mBigramSuggestions = new ArrayList<SuggestedWordInfo>(PREF_MAX_BIGRAMS); 268 269 if (!TextUtils.isEmpty(prevWordForBigram)) { 270 getAllBigrams(prevWordForBigram, wordComposer); 271 if (TextUtils.isEmpty(consideredWord)) { 272 // Nothing entered: return all bigrams for the previous word 273 int insertCount = Math.min(mBigramSuggestions.size(), mPrefMaxSuggestions); 274 for (int i = 0; i < insertCount; ++i) { 275 addBigramToSuggestions(mBigramSuggestions.get(i)); 276 } 277 } else { 278 // Word entered: return only bigrams that match the first char of the typed word 279 final char currentChar = consideredWord.charAt(0); 280 // TODO: Must pay attention to locale when changing case. 281 // TODO: Use codepoint instead of char 282 final char currentCharUpper = Character.toUpperCase(currentChar); 283 int count = 0; 284 final int bigramSuggestionSize = mBigramSuggestions.size(); 285 for (int i = 0; i < bigramSuggestionSize; i++) { 286 final SuggestedWordInfo bigramSuggestion = mBigramSuggestions.get(i); 287 final char bigramSuggestionFirstChar = 288 (char)bigramSuggestion.codePointAt(0); 289 if (bigramSuggestionFirstChar == currentChar 290 || bigramSuggestionFirstChar == currentCharUpper) { 291 addBigramToSuggestions(bigramSuggestion); 292 if (++count > mPrefMaxSuggestions) break; 293 } 294 } 295 } 296 } 297 298 } else if (wordComposer.size() > 1) { 299 final WordComposer wordComposerForLookup; 300 if (mTrailingSingleQuotesCount > 0) { 301 wordComposerForLookup = new WordComposer(wordComposer); 302 for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { 303 wordComposerForLookup.deleteLast(); 304 } 305 } else { 306 wordComposerForLookup = wordComposer; 307 } 308 // At second character typed, search the unigrams (scores being affected by bigrams) 309 for (final String key : mUnigramDictionaries.keySet()) { 310 // Skip UserUnigramDictionary and WhitelistDictionary to lookup 311 if (key.equals(DICT_KEY_USER_HISTORY_UNIGRAM) || key.equals(DICT_KEY_WHITELIST)) 312 continue; 313 final Dictionary dictionary = mUnigramDictionaries.get(key); 314 dictionary.getWords(wordComposerForLookup, prevWordForBigram, this, proximityInfo); 315 } 316 } 317 318 final CharSequence whitelistedWord = capitalizeWord(mIsAllUpperCase, 319 mIsFirstCharCapitalized, mWhiteListDictionary.getWhitelistedWord(consideredWord)); 320 321 final boolean hasAutoCorrection; 322 if (CORRECTION_FULL == correctionMode || CORRECTION_FULL_BIGRAM == correctionMode) { 323 final CharSequence autoCorrection = 324 AutoCorrection.computeAutoCorrectionWord(mUnigramDictionaries, wordComposer, 325 mSuggestions, consideredWord, mAutoCorrectionThreshold, 326 whitelistedWord); 327 hasAutoCorrection = (null != autoCorrection); 328 } else { 329 hasAutoCorrection = false; 330 } 331 332 if (whitelistedWord != null) { 333 if (mTrailingSingleQuotesCount > 0) { 334 final StringBuilder sb = new StringBuilder(whitelistedWord); 335 for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { 336 sb.appendCodePoint(Keyboard.CODE_SINGLE_QUOTE); 337 } 338 mSuggestions.add(0, new SuggestedWordInfo( 339 sb.toString(), SuggestedWordInfo.MAX_SCORE)); 340 } else { 341 mSuggestions.add(0, new SuggestedWordInfo( 342 whitelistedWord, SuggestedWordInfo.MAX_SCORE)); 343 } 344 } 345 346 mSuggestions.add(0, new SuggestedWordInfo(typedWord, SuggestedWordInfo.MAX_SCORE)); 347 SuggestedWordInfo.removeDups(mSuggestions); 348 349 final ArrayList<SuggestedWordInfo> suggestionsList; 350 if (DBG) { 351 suggestionsList = getSuggestionsInfoListWithDebugInfo(typedWord, mSuggestions); 352 } else { 353 suggestionsList = mSuggestions; 354 } 355 356 // TODO: Change this scheme - a boolean is not enough. A whitelisted word may be "valid" 357 // but still autocorrected from - in the case the whitelist only capitalizes the word. 358 // The whitelist should be case-insensitive, so it's not possible to be consistent with 359 // a boolean flag. Right now this is handled with a slight hack in 360 // WhitelistDictionary#shouldForciblyAutoCorrectFrom. 361 final boolean allowsToBeAutoCorrected = AutoCorrection.allowsToBeAutoCorrected( 362 getUnigramDictionaries(), consideredWord, wordComposer.isFirstCharCapitalized()) 363 // If we don't have a main dictionary, we never want to auto-correct. The reason for this 364 // is, the user may have a contact whose name happens to match a valid word in their 365 // language, and it will unexpectedly auto-correct. For example, if the user types in 366 // English with no dictionary and has a "Will" in their contact list, "will" would 367 // always auto-correct to "Will" which is unwanted. Hence, no main dict => no auto-correct. 368 && mHasMainDictionary; 369 370 boolean autoCorrectionAvailable = hasAutoCorrection; 371 if (correctionMode == CORRECTION_FULL || correctionMode == CORRECTION_FULL_BIGRAM) { 372 autoCorrectionAvailable |= !allowsToBeAutoCorrected; 373 } 374 // Don't auto-correct words with multiple capital letter 375 autoCorrectionAvailable &= !wordComposer.isMostlyCaps(); 376 autoCorrectionAvailable &= !wordComposer.isResumed(); 377 if (allowsToBeAutoCorrected && suggestionsList.size() > 1 && mAutoCorrectionThreshold > 0 378 && Suggest.shouldBlockAutoCorrectionBySafetyNet(typedWord, 379 suggestionsList.get(1).mWord)) { 380 autoCorrectionAvailable = false; 381 } 382 return new SuggestedWords(suggestionsList, 383 !allowsToBeAutoCorrected /* typedWordValid */, 384 autoCorrectionAvailable /* hasAutoCorrectionCandidate */, 385 allowsToBeAutoCorrected /* allowsToBeAutoCorrected */, 386 false /* isPunctuationSuggestions */, 387 false /* isObsoleteSuggestions */, 388 false /* isPrediction */); 389 } 390 391 /** 392 * Adds all bigram predictions for prevWord. Also checks the lower case version of prevWord if 393 * it contains any upper case characters. 394 */ 395 private void getAllBigrams(final CharSequence prevWord, final WordComposer wordComposer) { 396 if (StringUtils.hasUpperCase(prevWord)) { 397 // TODO: Must pay attention to locale when changing case. 398 final CharSequence lowerPrevWord = prevWord.toString().toLowerCase(); 399 for (final Dictionary dictionary : mBigramDictionaries.values()) { 400 dictionary.getBigrams(wordComposer, lowerPrevWord, this); 401 } 402 } 403 for (final Dictionary dictionary : mBigramDictionaries.values()) { 404 dictionary.getBigrams(wordComposer, prevWord, this); 405 } 406 } 407 408 private static ArrayList<SuggestedWordInfo> getSuggestionsInfoListWithDebugInfo( 409 final String typedWord, final ArrayList<SuggestedWordInfo> suggestions) { 410 final SuggestedWordInfo typedWordInfo = suggestions.get(0); 411 typedWordInfo.setDebugString("+"); 412 final int suggestionsSize = suggestions.size(); 413 final ArrayList<SuggestedWordInfo> suggestionsList = 414 new ArrayList<SuggestedWordInfo>(suggestionsSize); 415 suggestionsList.add(typedWordInfo); 416 // Note: i here is the index in mScores[], but the index in mSuggestions is one more 417 // than i because we added the typed word to mSuggestions without touching mScores. 418 for (int i = 0; i < suggestionsSize - 1; ++i) { 419 final SuggestedWordInfo cur = suggestions.get(i + 1); 420 final float normalizedScore = BinaryDictionary.calcNormalizedScore( 421 typedWord, cur.toString(), cur.mScore); 422 final String scoreInfoString; 423 if (normalizedScore > 0) { 424 scoreInfoString = String.format("%d (%4.2f)", cur.mScore, normalizedScore); 425 } else { 426 scoreInfoString = Integer.toString(cur.mScore); 427 } 428 cur.setDebugString(scoreInfoString); 429 suggestionsList.add(cur); 430 } 431 return suggestionsList; 432 } 433 434 // TODO: Use codepoint instead of char 435 @Override 436 public boolean addWord(final char[] word, final int offset, final int length, int score, 437 final int dicTypeId, final int dataType) { 438 int dataTypeForLog = dataType; 439 final ArrayList<SuggestedWordInfo> suggestions; 440 final int prefMaxSuggestions; 441 if (dataType == Dictionary.BIGRAM) { 442 suggestions = mBigramSuggestions; 443 prefMaxSuggestions = PREF_MAX_BIGRAMS; 444 } else { 445 suggestions = mSuggestions; 446 prefMaxSuggestions = mPrefMaxSuggestions; 447 } 448 449 int pos = 0; 450 451 // Check if it's the same word, only caps are different 452 if (StringUtils.equalsIgnoreCase(mConsideredWord, word, offset, length)) { 453 // TODO: remove this surrounding if clause and move this logic to 454 // getSuggestedWordBuilder. 455 if (suggestions.size() > 0) { 456 final SuggestedWordInfo currentHighestWord = suggestions.get(0); 457 // If the current highest word is also equal to typed word, we need to compare 458 // frequency to determine the insertion position. This does not ensure strictly 459 // correct ordering, but ensures the top score is on top which is enough for 460 // removing duplicates correctly. 461 if (StringUtils.equalsIgnoreCase(currentHighestWord.mWord, word, offset, length) 462 && score <= currentHighestWord.mScore) { 463 pos = 1; 464 } 465 } 466 } else { 467 // Check the last one's score and bail 468 if (suggestions.size() >= prefMaxSuggestions 469 && suggestions.get(prefMaxSuggestions - 1).mScore >= score) return true; 470 while (pos < suggestions.size()) { 471 final int curScore = suggestions.get(pos).mScore; 472 if (curScore < score 473 || (curScore == score && length < suggestions.get(pos).codePointCount())) { 474 break; 475 } 476 pos++; 477 } 478 } 479 if (pos >= prefMaxSuggestions) { 480 return true; 481 } 482 483 final StringBuilder sb = new StringBuilder(getApproxMaxWordLength()); 484 // TODO: Must pay attention to locale when changing case. 485 if (mIsAllUpperCase) { 486 sb.append(new String(word, offset, length).toUpperCase()); 487 } else if (mIsFirstCharCapitalized) { 488 sb.append(Character.toUpperCase(word[offset])); 489 if (length > 1) { 490 sb.append(word, offset + 1, length - 1); 491 } 492 } else { 493 sb.append(word, offset, length); 494 } 495 for (int i = mTrailingSingleQuotesCount - 1; i >= 0; --i) { 496 sb.appendCodePoint(Keyboard.CODE_SINGLE_QUOTE); 497 } 498 suggestions.add(pos, new SuggestedWordInfo(sb, score)); 499 if (suggestions.size() > prefMaxSuggestions) { 500 suggestions.remove(prefMaxSuggestions); 501 } else { 502 LatinImeLogger.onAddSuggestedWord(sb.toString(), dicTypeId, dataTypeForLog); 503 } 504 return true; 505 } 506 507 public void close() { 508 final HashSet<Dictionary> dictionaries = new HashSet<Dictionary>(); 509 dictionaries.addAll(mUnigramDictionaries.values()); 510 dictionaries.addAll(mBigramDictionaries.values()); 511 for (final Dictionary dictionary : dictionaries) { 512 dictionary.close(); 513 } 514 mHasMainDictionary = false; 515 } 516 517 // TODO: Resolve the inconsistencies between the native auto correction algorithms and 518 // this safety net 519 public static boolean shouldBlockAutoCorrectionBySafetyNet(final String typedWord, 520 final CharSequence suggestion) { 521 // Safety net for auto correction. 522 // Actually if we hit this safety net, it's a bug. 523 // If user selected aggressive auto correction mode, there is no need to use the safety 524 // net. 525 // If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH, 526 // we should not use net because relatively edit distance can be big. 527 final int typedWordLength = typedWord.length(); 528 if (typedWordLength < Suggest.MINIMUM_SAFETY_NET_CHAR_LENGTH) { 529 return false; 530 } 531 final int maxEditDistanceOfNativeDictionary = 532 (typedWordLength < 5 ? 2 : typedWordLength / 2) + 1; 533 final int distance = BinaryDictionary.editDistance(typedWord, suggestion.toString()); 534 if (DBG) { 535 Log.d(TAG, "Autocorrected edit distance = " + distance 536 + ", " + maxEditDistanceOfNativeDictionary); 537 } 538 if (distance > maxEditDistanceOfNativeDictionary) { 539 if (DBG) { 540 Log.e(TAG, "Safety net: before = " + typedWord + ", after = " + suggestion); 541 Log.e(TAG, "(Error) The edit distance of this correction exceeds limit. " 542 + "Turning off auto-correction."); 543 } 544 return true; 545 } else { 546 return false; 547 } 548 } 549 } 550