LatinIME/java/src/com/android/inputmethod/latin/Suggest.java

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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.android.inputmethod.latin;
import android.content.Context;
import android.text.AutoText;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
/**
* This class loads a dictionary and provides a list of suggestions for a given sequence of
* characters. This includes corrections and completions.
*/
public class Suggest implements Dictionary.WordCallback {
public static final String TAG = Suggest.class.getSimpleName();
public static final int APPROX_MAX_WORD_LENGTH = 32;
public static final int CORRECTION_NONE = 0;
public static final int CORRECTION_BASIC = 1;
public static final int CORRECTION_FULL = 2;
public static final int CORRECTION_FULL_BIGRAM = 3;
/**
* Words that appear in both bigram and unigram data gets multiplier ranging from
* BIGRAM_MULTIPLIER_MIN to BIGRAM_MULTIPLIER_MAX depending on the score from
* bigram data.
*/
public static final double BIGRAM_MULTIPLIER_MIN = 1.2;
public static final double BIGRAM_MULTIPLIER_MAX = 1.5;
/**
* Maximum possible bigram frequency. Will depend on how many bits are being used in data
* structure. Maximum bigram frequency will get the BIGRAM_MULTIPLIER_MAX as the multiplier.
*/
public static final int MAXIMUM_BIGRAM_FREQUENCY = 127;
// It seems the following values are only used for logging.
public static final int DIC_USER_TYPED = 0;
public static final int DIC_MAIN = 1;
public static final int DIC_USER = 2;
public static final int DIC_USER_UNIGRAM = 3;
public static final int DIC_CONTACTS = 4;
public static final int DIC_USER_BIGRAM = 5;
// If you add a type of dictionary, increment DIC_TYPE_LAST_ID
// TODO: this value seems unused. Remove it?
public static final int DIC_TYPE_LAST_ID = 5;
public static final String DICT_KEY_MAIN = "main";
public static final String DICT_KEY_CONTACTS = "contacts";
// User dictionary, the system-managed one.
public static final String DICT_KEY_USER = "user";
// User unigram dictionary, internal to LatinIME
public static final String DICT_KEY_USER_UNIGRAM = "user_unigram";
// User bigram dictionary, internal to LatinIME
public static final String DICT_KEY_USER_BIGRAM = "user_bigram";
public static final String DICT_KEY_WHITELIST ="whitelist";
private static final boolean DBG = LatinImeLogger.sDBG;
private AutoCorrection mAutoCorrection;
private Dictionary mMainDict;
private WhitelistDictionary mWhiteListDictionary;
private final Map<String, Dictionary> mUnigramDictionaries = new HashMap<String, Dictionary>();
private final Map<String, Dictionary> mBigramDictionaries = new HashMap<String, Dictionary>();
private int mPrefMaxSuggestions = 18;
private static final int PREF_MAX_BIGRAMS = 60;
private boolean mQuickFixesEnabled;
private double mAutoCorrectionThreshold;
private int[] mScores = new int[mPrefMaxSuggestions];
private int[] mBigramScores = new int[PREF_MAX_BIGRAMS];
private ArrayList<CharSequence> mSuggestions = new ArrayList<CharSequence>();
ArrayList<CharSequence> mBigramSuggestions = new ArrayList<CharSequence>();
private ArrayList<CharSequence> mStringPool = new ArrayList<CharSequence>();
private CharSequence mTypedWord;
// TODO: Remove these member variables by passing more context to addWord() callback method
private boolean mIsFirstCharCapitalized;
private boolean mIsAllUpperCase;
private int mCorrectionMode = CORRECTION_BASIC;
public Suggest(Context context, int dictionaryResId, Locale locale) {
init(context, DictionaryFactory.createDictionaryFromManager(context, locale,
dictionaryResId));
}
/* package for test */ Suggest(Context context, File dictionary, long startOffset, long length,
Flag[] flagArray) {
init(null, DictionaryFactory.createDictionaryForTest(context, dictionary, startOffset,
length, flagArray));
}
private void init(Context context, Dictionary mainDict) {
mMainDict = mainDict;
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, mainDict);
addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, mainDict);
mWhiteListDictionary = WhitelistDictionary.init(context);
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_WHITELIST, mWhiteListDictionary);
mAutoCorrection = new AutoCorrection();
initPool();
}
private void addOrReplaceDictionary(Map<String, Dictionary> dictionaries, String key,
Dictionary dict) {
final Dictionary oldDict = (dict == null)
? dictionaries.remove(key)
: dictionaries.put(key, dict);
if (oldDict != null && dict != oldDict) {
oldDict.close();
}
}
public void resetMainDict(Context context, int dictionaryResId, Locale locale) {
final Dictionary newMainDict = DictionaryFactory.createDictionaryFromManager(
context, locale, dictionaryResId);
mMainDict = newMainDict;
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_MAIN, newMainDict);
addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_MAIN, newMainDict);
}
private void initPool() {
for (int i = 0; i < mPrefMaxSuggestions; i++) {
StringBuilder sb = new StringBuilder(getApproxMaxWordLength());
mStringPool.add(sb);
}
}
public void setQuickFixesEnabled(boolean enabled) {
mQuickFixesEnabled = enabled;
}
public int getCorrectionMode() {
return mCorrectionMode;
}
public void setCorrectionMode(int mode) {
mCorrectionMode = mode;
}
public boolean hasMainDictionary() {
return mMainDict != null;
}
public Map<String, Dictionary> getUnigramDictionaries() {
return mUnigramDictionaries;
}
public int getApproxMaxWordLength() {
return APPROX_MAX_WORD_LENGTH;
}
/**
* Sets an optional user dictionary resource to be loaded. The user dictionary is consulted
* before the main dictionary, if set. This refers to the system-managed user dictionary.
*/
public void setUserDictionary(Dictionary userDictionary) {
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER, userDictionary);
}
/**
* Sets an optional contacts dictionary resource to be loaded. It is also possible to remove
* the contacts dictionary by passing null to this method. In this case no contacts dictionary
* won't be used.
*/
public void setContactsDictionary(Dictionary contactsDictionary) {
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary);
addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_CONTACTS, contactsDictionary);
}
public void setUserUnigramDictionary(Dictionary userUnigramDictionary) {
addOrReplaceDictionary(mUnigramDictionaries, DICT_KEY_USER_UNIGRAM, userUnigramDictionary);
}
public void setUserBigramDictionary(Dictionary userBigramDictionary) {
addOrReplaceDictionary(mBigramDictionaries, DICT_KEY_USER_BIGRAM, userBigramDictionary);
}
public void setAutoCorrectionThreshold(double threshold) {
mAutoCorrectionThreshold = threshold;
}
public boolean isAggressiveAutoCorrectionMode() {
return (mAutoCorrectionThreshold == 0);
}
/**
* Number of suggestions to generate from the input key sequence. This has
* to be a number between 1 and 100 (inclusive).
* @param maxSuggestions
* @throws IllegalArgumentException if the number is out of range
*/
public void setMaxSuggestions(int maxSuggestions) {
if (maxSuggestions < 1 || maxSuggestions > 100) {
throw new IllegalArgumentException("maxSuggestions must be between 1 and 100");
}
mPrefMaxSuggestions = maxSuggestions;
mScores = new int[mPrefMaxSuggestions];
mBigramScores = new int[PREF_MAX_BIGRAMS];
collectGarbage(mSuggestions, mPrefMaxSuggestions);
while (mStringPool.size() < mPrefMaxSuggestions) {
StringBuilder sb = new StringBuilder(getApproxMaxWordLength());
mStringPool.add(sb);
}
}
/**
* Returns a object which represents suggested words that match the list of character codes
* passed in. This object contents will be overwritten the next time this function is called.
* @param view a view for retrieving the context for AutoText
* @param wordComposer contains what is currently being typed
* @param prevWordForBigram previous word (used only for bigram)
* @return suggested words object.
*/
public SuggestedWords getSuggestions(View view, WordComposer wordComposer,
CharSequence prevWordForBigram) {
return getSuggestedWordBuilder(view, wordComposer, prevWordForBigram).build();
}
private CharSequence capitalizeWord(boolean all, boolean first, CharSequence word) {
if (TextUtils.isEmpty(word) || !(all || first)) return word;
final int wordLength = word.length();
final int poolSize = mStringPool.size();
final StringBuilder sb =
poolSize > 0 ? (StringBuilder) mStringPool.remove(poolSize - 1)
: new StringBuilder(getApproxMaxWordLength());
sb.setLength(0);
// TODO: Must pay attention to locale when changing case.
if (all) {
sb.append(word.toString().toUpperCase());
} else if (first) {
sb.append(Character.toUpperCase(word.charAt(0)));
if (wordLength > 1) {
sb.append(word.subSequence(1, wordLength));
}
}
return sb;
}
protected void addBigramToSuggestions(CharSequence bigram) {
final int poolSize = mStringPool.size();
final StringBuilder sb = poolSize > 0 ?
(StringBuilder) mStringPool.remove(poolSize - 1)
: new StringBuilder(getApproxMaxWordLength());
sb.setLength(0);
sb.append(bigram);
mSuggestions.add(sb);
}
// TODO: cleanup dictionaries looking up and suggestions building with SuggestedWords.Builder
public SuggestedWords.Builder getSuggestedWordBuilder(View view, WordComposer wordComposer,
CharSequence prevWordForBigram) {
LatinImeLogger.onStartSuggestion(prevWordForBigram);
mAutoCorrection.init();
mIsFirstCharCapitalized = wordComposer.isFirstCharCapitalized();
mIsAllUpperCase = wordComposer.isAllUpperCase();
collectGarbage(mSuggestions, mPrefMaxSuggestions);
Arrays.fill(mScores, 0);
// Save a lowercase version of the original word
CharSequence typedWord = wordComposer.getTypedWord();
if (typedWord != null) {
final String typedWordString = typedWord.toString();
typedWord = typedWordString;
// Treating USER_TYPED as UNIGRAM suggestion for logging now.
LatinImeLogger.onAddSuggestedWord(typedWordString, Suggest.DIC_USER_TYPED,
Dictionary.DataType.UNIGRAM);
}
mTypedWord = typedWord;
if (wordComposer.size() <= 1 && (mCorrectionMode == CORRECTION_FULL_BIGRAM
|| mCorrectionMode == CORRECTION_BASIC)) {
// At first character typed, search only the bigrams
Arrays.fill(mBigramScores, 0);
collectGarbage(mBigramSuggestions, PREF_MAX_BIGRAMS);
if (!TextUtils.isEmpty(prevWordForBigram)) {
CharSequence lowerPrevWord = prevWordForBigram.toString().toLowerCase();
if (mMainDict != null && mMainDict.isValidWord(lowerPrevWord)) {
prevWordForBigram = lowerPrevWord;
}
for (final Dictionary dictionary : mBigramDictionaries.values()) {
dictionary.getBigrams(wordComposer, prevWordForBigram, this);
}
if (TextUtils.isEmpty(typedWord)) {
// Nothing entered: return all bigrams for the previous word
int insertCount = Math.min(mBigramSuggestions.size(), mPrefMaxSuggestions);
for (int i = 0; i < insertCount; ++i) {
addBigramToSuggestions(mBigramSuggestions.get(i));
}
} else {
// Word entered: return only bigrams that match the first char of the typed word
final char currentChar = typedWord.charAt(0);
// TODO: Must pay attention to locale when changing case.
final char currentCharUpper = Character.toUpperCase(currentChar);
int count = 0;
final int bigramSuggestionSize = mBigramSuggestions.size();
for (int i = 0; i < bigramSuggestionSize; i++) {
final CharSequence bigramSuggestion = mBigramSuggestions.get(i);
final char bigramSuggestionFirstChar = bigramSuggestion.charAt(0);
if (bigramSuggestionFirstChar == currentChar
|| bigramSuggestionFirstChar == currentCharUpper) {
addBigramToSuggestions(bigramSuggestion);
if (++count > mPrefMaxSuggestions) break;
}
}
}
}
} else if (wordComposer.size() > 1) {
// At second character typed, search the unigrams (scores being affected by bigrams)
for (final String key : mUnigramDictionaries.keySet()) {
// Skip UserUnigramDictionary and WhitelistDictionary to lookup
if (key.equals(DICT_KEY_USER_UNIGRAM) || key.equals(DICT_KEY_WHITELIST))
continue;
final Dictionary dictionary = mUnigramDictionaries.get(key);
dictionary.getWords(wordComposer, this);
}
}
CharSequence autoText = null;
final String typedWordString = typedWord == null ? null : typedWord.toString();
if (typedWord != null) {
// Apply quick fix only for the typed word.
if (mQuickFixesEnabled) {
final String lowerCaseTypedWord = typedWordString.toLowerCase();
CharSequence tempAutoText = capitalizeWord(
mIsAllUpperCase, mIsFirstCharCapitalized, AutoText.get(
lowerCaseTypedWord, 0, lowerCaseTypedWord.length(), view));
// TODO: cleanup canAdd
// Is there an AutoText (also known as Quick Fixes) correction?
// Capitalize as needed
boolean canAdd = tempAutoText != null;
// Is that correction already the current prediction (or original word)?
canAdd &= !TextUtils.equals(tempAutoText, typedWord);
// Is that correction already the next predicted word?
if (canAdd && mSuggestions.size() > 0 && mCorrectionMode != CORRECTION_BASIC) {
canAdd &= !TextUtils.equals(tempAutoText, mSuggestions.get(0));
}
if (canAdd) {
if (DBG) {
Log.d(TAG, "Auto corrected by AUTOTEXT.");
}
autoText = tempAutoText;
}
}
}
CharSequence whitelistedWord = capitalizeWord(mIsAllUpperCase, mIsFirstCharCapitalized,
mWhiteListDictionary.getWhiteListedWord(typedWordString));
mAutoCorrection.updateAutoCorrectionStatus(mUnigramDictionaries, wordComposer,
mSuggestions, mScores, typedWord, mAutoCorrectionThreshold, mCorrectionMode,
autoText, whitelistedWord);
if (autoText != null) {
mSuggestions.add(0, autoText);
}
if (whitelistedWord != null) {
mSuggestions.add(0, whitelistedWord);
}
if (typedWord != null) {
mSuggestions.add(0, typedWordString);
}
removeDupes();
if (DBG) {
double normalizedScore = mAutoCorrection.getNormalizedScore();
ArrayList<SuggestedWords.SuggestedWordInfo> scoreInfoList =
new ArrayList<SuggestedWords.SuggestedWordInfo>();
scoreInfoList.add(new SuggestedWords.SuggestedWordInfo("+", false));
for (int i = 0; i < mScores.length; ++i) {
if (normalizedScore > 0) {
final String scoreThreshold = String.format("%d (%4.2f)", mScores[i],
normalizedScore);
scoreInfoList.add(
new SuggestedWords.SuggestedWordInfo(scoreThreshold, false));
normalizedScore = 0.0;
} else {
final String score = Integer.toString(mScores[i]);
scoreInfoList.add(new SuggestedWords.SuggestedWordInfo(score, false));
}
}
for (int i = mScores.length; i < mSuggestions.size(); ++i) {
scoreInfoList.add(new SuggestedWords.SuggestedWordInfo("--", false));
}
return new SuggestedWords.Builder().addWords(mSuggestions, scoreInfoList);
}
return new SuggestedWords.Builder().addWords(mSuggestions, null);
}
private void removeDupes() {
final ArrayList<CharSequence> suggestions = mSuggestions;
if (suggestions.size() < 2) return;
int i = 1;
// Don't cache suggestions.size(), since we may be removing items
while (i < suggestions.size()) {
final CharSequence cur = suggestions.get(i);
// Compare each candidate with each previous candidate
for (int j = 0; j < i; j++) {
CharSequence previous = suggestions.get(j);
if (TextUtils.equals(cur, previous)) {
removeFromSuggestions(i);
i--;
break;
}
}
i++;
}
}
private void removeFromSuggestions(int index) {
CharSequence garbage = mSuggestions.remove(index);
if (garbage != null && garbage instanceof StringBuilder) {
mStringPool.add(garbage);
}
}
public boolean hasAutoCorrection() {
return mAutoCorrection.hasAutoCorrection();
}
@Override
public boolean addWord(final char[] word, final int offset, final int length, int score,
final int dicTypeId, final Dictionary.DataType dataType) {
Dictionary.DataType dataTypeForLog = dataType;
final ArrayList<CharSequence> suggestions;
final int[] sortedScores;
final int prefMaxSuggestions;
if(dataType == Dictionary.DataType.BIGRAM) {
suggestions = mBigramSuggestions;
sortedScores = mBigramScores;
prefMaxSuggestions = PREF_MAX_BIGRAMS;
} else {
suggestions = mSuggestions;
sortedScores = mScores;
prefMaxSuggestions = mPrefMaxSuggestions;
}
int pos = 0;
// Check if it's the same word, only caps are different
if (Utils.equalsIgnoreCase(mTypedWord, word, offset, length)) {
// TODO: remove this surrounding if clause and move this logic to
// getSuggestedWordBuilder.
if (suggestions.size() > 0) {
final String currentHighestWord = suggestions.get(0).toString();
// If the current highest word is also equal to typed word, we need to compare
// frequency to determine the insertion position. This does not ensure strictly
// correct ordering, but ensures the top score is on top which is enough for
// removing duplicates correctly.
if (Utils.equalsIgnoreCase(currentHighestWord, word, offset, length)
&& score <= sortedScores[0]) {
pos = 1;
}
}
} else {
if (dataType == Dictionary.DataType.UNIGRAM) {
// Check if the word was already added before (by bigram data)
int bigramSuggestion = searchBigramSuggestion(word,offset,length);
if(bigramSuggestion >= 0) {
dataTypeForLog = Dictionary.DataType.BIGRAM;
// turn freq from bigram into multiplier specified above
double multiplier = (((double) mBigramScores[bigramSuggestion])
/ MAXIMUM_BIGRAM_FREQUENCY)
* (BIGRAM_MULTIPLIER_MAX - BIGRAM_MULTIPLIER_MIN)
+ BIGRAM_MULTIPLIER_MIN;
/* Log.d(TAG,"bigram num: " + bigramSuggestion
+ " wordB: " + mBigramSuggestions.get(bigramSuggestion).toString()
+ " currentScore: " + score + " bigramScore: "
+ mBigramScores[bigramSuggestion]
+ " multiplier: " + multiplier); */
score = (int)Math.round((score * multiplier));
}
}
// Check the last one's score and bail
if (sortedScores[prefMaxSuggestions - 1] >= score) return true;
while (pos < prefMaxSuggestions) {
if (sortedScores[pos] < score
|| (sortedScores[pos] == score && length < suggestions.get(pos).length())) {
break;
}
pos++;
}
}
if (pos >= prefMaxSuggestions) {
return true;
}
System.arraycopy(sortedScores, pos, sortedScores, pos + 1, prefMaxSuggestions - pos - 1);
sortedScores[pos] = score;
int poolSize = mStringPool.size();
StringBuilder sb = poolSize > 0 ? (StringBuilder) mStringPool.remove(poolSize - 1)
: new StringBuilder(getApproxMaxWordLength());
sb.setLength(0);
// TODO: Must pay attention to locale when changing case.
if (mIsAllUpperCase) {
sb.append(new String(word, offset, length).toUpperCase());
} else if (mIsFirstCharCapitalized) {
sb.append(Character.toUpperCase(word[offset]));
if (length > 1) {
sb.append(word, offset + 1, length - 1);
}
} else {
sb.append(word, offset, length);
}
suggestions.add(pos, sb);
if (suggestions.size() > prefMaxSuggestions) {
CharSequence garbage = suggestions.remove(prefMaxSuggestions);
if (garbage instanceof StringBuilder) {
mStringPool.add(garbage);
}
} else {
LatinImeLogger.onAddSuggestedWord(sb.toString(), dicTypeId, dataTypeForLog);
}
return true;
}
private int searchBigramSuggestion(final char[] word, final int offset, final int length) {
// TODO This is almost O(n^2). Might need fix.
// search whether the word appeared in bigram data
int bigramSuggestSize = mBigramSuggestions.size();
for(int i = 0; i < bigramSuggestSize; i++) {
if(mBigramSuggestions.get(i).length() == length) {
boolean chk = true;
for(int j = 0; j < length; j++) {
if(mBigramSuggestions.get(i).charAt(j) != word[offset+j]) {
chk = false;
break;
}
}
if(chk) return i;
}
}
return -1;
}
private void collectGarbage(ArrayList<CharSequence> suggestions, int prefMaxSuggestions) {
int poolSize = mStringPool.size();
int garbageSize = suggestions.size();
while (poolSize < prefMaxSuggestions && garbageSize > 0) {
CharSequence garbage = suggestions.get(garbageSize - 1);
if (garbage != null && garbage instanceof StringBuilder) {
mStringPool.add(garbage);
poolSize++;
}
garbageSize--;
}
if (poolSize == prefMaxSuggestions + 1) {
Log.w("Suggest", "String pool got too big: " + poolSize);
}
suggestions.clear();
}
public void close() {
final Set<Dictionary> dictionaries = new HashSet<Dictionary>();
dictionaries.addAll(mUnigramDictionaries.values());
dictionaries.addAll(mBigramDictionaries.values());
for (final Dictionary dictionary : dictionaries) {
dictionary.close();
}
mMainDict = null;
}
}