/*
* Copyright (C) 2011 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.sugree.inputmethod.latin.spellcheck;
import android.content.Intent;
import android.content.res.Resources;
import android.service.textservice.SpellCheckerService;
import android.text.TextUtils;
import android.util.Log;
import android.view.textservice.SuggestionsInfo;
import android.view.textservice.TextInfo;
import com.android.inputmethod.compat.ArraysCompatUtils;
import com.android.inputmethod.keyboard.ProximityInfo;
import com.sugree.inputmethod.latin.R;
import com.sugree.inputmethod.latin.BinaryDictionary;
import com.sugree.inputmethod.latin.Dictionary;
import com.sugree.inputmethod.latin.DictionaryCollection;
import com.sugree.inputmethod.latin.DictionaryFactory;
import com.sugree.inputmethod.latin.Flag;
import com.sugree.inputmethod.latin.LocaleUtils;
import com.sugree.inputmethod.latin.SynchronouslyLoadedContactsDictionary;
import com.sugree.inputmethod.latin.SynchronouslyLoadedUserDictionary;
import com.sugree.inputmethod.latin.Utils;
import com.sugree.inputmethod.latin.WhitelistDictionary;
import com.sugree.inputmethod.latin.WordComposer;
import com.sugree.inputmethod.latin.Dictionary.DataType;
import com.sugree.inputmethod.latin.Dictionary.WordCallback;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;
/**
* Service for spell checking, using LatinIME's dictionaries and mechanisms.
*/
public class AndroidSpellCheckerService extends SpellCheckerService {
private static final String TAG = AndroidSpellCheckerService.class.getSimpleName();
private static final boolean DBG = false;
private static final int POOL_SIZE = 2;
private static final int CAPITALIZE_NONE = 0; // No caps, or mixed case
private static final int CAPITALIZE_FIRST = 1; // First only
private static final int CAPITALIZE_ALL = 2; // All caps
private final static String[] EMPTY_STRING_ARRAY = new String[0];
private final static Flag[] USE_FULL_EDIT_DISTANCE_FLAG_ARRAY;
static {
// See BinaryDictionary.java for an explanation of these flags
// Specifially, ALL_CONFIG_FLAGS means that we want to consider all flags with the
// current dictionary configuration - for example, consider the UMLAUT flag
// so that it will be turned on for German dictionaries and off for others.
USE_FULL_EDIT_DISTANCE_FLAG_ARRAY = Arrays.copyOf(BinaryDictionary.ALL_CONFIG_FLAGS,
BinaryDictionary.ALL_CONFIG_FLAGS.length + 1);
USE_FULL_EDIT_DISTANCE_FLAG_ARRAY[BinaryDictionary.ALL_CONFIG_FLAGS.length] =
BinaryDictionary.FLAG_USE_FULL_EDIT_DISTANCE;
}
private Map<String, DictionaryPool> mDictionaryPools =
Collections.synchronizedMap(new TreeMap<String, DictionaryPool>());
private Map<String, Dictionary> mUserDictionaries =
Collections.synchronizedMap(new TreeMap<String, Dictionary>());
private Map<String, Dictionary> mWhitelistDictionaries =
Collections.synchronizedMap(new TreeMap<String, Dictionary>());
private SynchronouslyLoadedContactsDictionary mContactsDictionary;
// The threshold for a candidate to be offered as a suggestion.
private double mSuggestionThreshold;
// The threshold for a suggestion to be considered "likely".
private double mLikelyThreshold;
@Override public void onCreate() {
super.onCreate();
mSuggestionThreshold =
Double.parseDouble(getString(R.string.spellchecker_suggestion_threshold_value));
mLikelyThreshold =
Double.parseDouble(getString(R.string.spellchecker_likely_threshold_value));
}
@Override
public Session createSession() {
return new AndroidSpellCheckerSession(this);
}
private static SuggestionsInfo getNotInDictEmptySuggestions() {
return new SuggestionsInfo(0, EMPTY_STRING_ARRAY);
}
private static SuggestionsInfo getInDictEmptySuggestions() {
return new SuggestionsInfo(SuggestionsInfo.RESULT_ATTR_IN_THE_DICTIONARY,
EMPTY_STRING_ARRAY);
}
private static class SuggestionsGatherer implements WordCallback {
public static class Result {
public final String[] mSuggestions;
public final boolean mHasLikelySuggestions;
public Result(final String[] gatheredSuggestions, final boolean hasLikelySuggestions) {
mSuggestions = gatheredSuggestions;
mHasLikelySuggestions = hasLikelySuggestions;
}
}
private final ArrayList<CharSequence> mSuggestions;
private final int[] mScores;
private final String mOriginalText;
private final double mSuggestionThreshold;
private final double mLikelyThreshold;
private final int mMaxLength;
private int mLength = 0;
// The two following attributes are only ever filled if the requested max length
// is 0 (or less, which is treated the same).
private String mBestSuggestion = null;
private int mBestScore = Integer.MIN_VALUE; // As small as possible
SuggestionsGatherer(final String originalText, final double suggestionThreshold,
final double likelyThreshold, final int maxLength) {
mOriginalText = originalText;
mSuggestionThreshold = suggestionThreshold;
mLikelyThreshold = likelyThreshold;
mMaxLength = maxLength;
mSuggestions = new ArrayList<CharSequence>(maxLength + 1);
mScores = new int[mMaxLength];
}
@Override
synchronized public boolean addWord(char[] word, int wordOffset, int wordLength, int score,
int dicTypeId, DataType dataType) {
final int positionIndex = ArraysCompatUtils.binarySearch(mScores, 0, mLength, score);
// binarySearch returns the index if the element exists, and -<insertion index> - 1
// if it doesn't. See documentation for binarySearch.
final int insertIndex = positionIndex >= 0 ? positionIndex : -positionIndex - 1;
if (insertIndex == 0 && mLength >= mMaxLength) {
// In the future, we may want to keep track of the best suggestion score even if
// we are asked for 0 suggestions. In this case, we can use the following
// (tested) code to keep it:
// If the maxLength is 0 (should never be less, but if it is, it's treated as 0)
// then we need to keep track of the best suggestion in mBestScore and
// mBestSuggestion. This is so that we know whether the best suggestion makes
// the score cutoff, since we need to know that to return a meaningful
// looksLikeTypo.
// if (0 >= mMaxLength) {
// if (score > mBestScore) {
// mBestScore = score;
// mBestSuggestion = new String(word, wordOffset, wordLength);
// }
// }
return true;
}
if (insertIndex >= mMaxLength) {
// We found a suggestion, but its score is too weak to be kept considering
// the suggestion limit.
return true;
}
// Compute the normalized score and skip this word if it's normalized score does not
// make the threshold.
final String wordString = new String(word, wordOffset, wordLength);
final double normalizedScore =
Utils.calcNormalizedScore(mOriginalText, wordString, score);
if (normalizedScore < mSuggestionThreshold) {
if (DBG) Log.i(TAG, wordString + " does not make the score threshold");
return true;
}
if (mLength < mMaxLength) {
final int copyLen = mLength - insertIndex;
++mLength;
System.arraycopy(mScores, insertIndex, mScores, insertIndex + 1, copyLen);
mSuggestions.add(insertIndex, wordString);
} else {
System.arraycopy(mScores, 1, mScores, 0, insertIndex);
mSuggestions.add(insertIndex, wordString);
mSuggestions.remove(0);
}
mScores[insertIndex] = score;
return true;
}
public Result getResults(final int capitalizeType, final Locale locale) {
final String[] gatheredSuggestions;
final boolean hasLikelySuggestions;
if (0 == mLength) {
// Either we found no suggestions, or we found some BUT the max length was 0.
// If we found some mBestSuggestion will not be null. If it is null, then
// we found none, regardless of the max length.
if (null == mBestSuggestion) {
gatheredSuggestions = null;
hasLikelySuggestions = false;
} else {
gatheredSuggestions = EMPTY_STRING_ARRAY;
final double normalizedScore =
Utils.calcNormalizedScore(mOriginalText, mBestSuggestion, mBestScore);
hasLikelySuggestions = (normalizedScore > mLikelyThreshold);
}
} else {
if (DBG) {
if (mLength != mSuggestions.size()) {
Log.e(TAG, "Suggestion size is not the same as stored mLength");
}
for (int i = mLength - 1; i >= 0; --i) {
Log.i(TAG, "" + mScores[i] + " " + mSuggestions.get(i));
}
}
Collections.reverse(mSuggestions);
Utils.removeDupes(mSuggestions);
if (CAPITALIZE_ALL == capitalizeType) {
for (int i = 0; i < mSuggestions.size(); ++i) {
// get(i) returns a CharSequence which is actually a String so .toString()
// should return the same object.
mSuggestions.set(i, mSuggestions.get(i).toString().toUpperCase(locale));
}
} else if (CAPITALIZE_FIRST == capitalizeType) {
for (int i = 0; i < mSuggestions.size(); ++i) {
// Likewise
mSuggestions.set(i, Utils.toTitleCase(mSuggestions.get(i).toString(),
locale));
}
}
// This returns a String[], while toArray() returns an Object[] which cannot be cast
// into a String[].
gatheredSuggestions = mSuggestions.toArray(EMPTY_STRING_ARRAY);
final int bestScore = mScores[mLength - 1];
final CharSequence bestSuggestion = mSuggestions.get(0);
final double normalizedScore =
Utils.calcNormalizedScore(mOriginalText, bestSuggestion, bestScore);
hasLikelySuggestions = (normalizedScore > mLikelyThreshold);
if (DBG) {
Log.i(TAG, "Best suggestion : " + bestSuggestion + ", score " + bestScore);
Log.i(TAG, "Normalized score = " + normalizedScore
+ " (threshold " + mLikelyThreshold
+ ") => hasLikelySuggestions = " + hasLikelySuggestions);
}
}
return new Result(gatheredSuggestions, hasLikelySuggestions);
}
}
@Override
public boolean onUnbind(final Intent intent) {
final Map<String, DictionaryPool> oldPools = mDictionaryPools;
mDictionaryPools = Collections.synchronizedMap(new TreeMap<String, DictionaryPool>());
final Map<String, Dictionary> oldUserDictionaries = mUserDictionaries;
mUserDictionaries = Collections.synchronizedMap(new TreeMap<String, Dictionary>());
final Map<String, Dictionary> oldWhitelistDictionaries = mWhitelistDictionaries;
mWhitelistDictionaries = Collections.synchronizedMap(new TreeMap<String, Dictionary>());
for (DictionaryPool pool : oldPools.values()) {
pool.close();
}
for (Dictionary dict : oldUserDictionaries.values()) {
dict.close();
}
for (Dictionary dict : oldWhitelistDictionaries.values()) {
dict.close();
}
if (null != mContactsDictionary) {
// The synchronously loaded contacts dictionary should have been in one
// or several pools, but it is shielded against multiple closing and it's
// safe to call it several times.
final SynchronouslyLoadedContactsDictionary dictToClose = mContactsDictionary;
mContactsDictionary = null;
dictToClose.close();
}
return false;
}
private DictionaryPool getDictionaryPool(final String locale) {
DictionaryPool pool = mDictionaryPools.get(locale);
if (null == pool) {
final Locale localeObject = LocaleUtils.constructLocaleFromString(locale);
pool = new DictionaryPool(POOL_SIZE, this, localeObject);
mDictionaryPools.put(locale, pool);
}
return pool;
}
public DictAndProximity createDictAndProximity(final Locale locale) {
final ProximityInfo proximityInfo = ProximityInfo.createSpellCheckerProximityInfo();
final Resources resources = getResources();
final int fallbackResourceId = Utils.getMainDictionaryResourceId(resources);
final DictionaryCollection dictionaryCollection =
DictionaryFactory.createDictionaryFromManager(this, locale, fallbackResourceId,
USE_FULL_EDIT_DISTANCE_FLAG_ARRAY);
final String localeStr = locale.toString();
Dictionary userDictionary = mUserDictionaries.get(localeStr);
if (null == userDictionary) {
userDictionary = new SynchronouslyLoadedUserDictionary(this, localeStr, true);
mUserDictionaries.put(localeStr, userDictionary);
}
dictionaryCollection.addDictionary(userDictionary);
Dictionary whitelistDictionary = mWhitelistDictionaries.get(localeStr);
if (null == whitelistDictionary) {
whitelistDictionary = new WhitelistDictionary(this, locale);
mWhitelistDictionaries.put(localeStr, whitelistDictionary);
}
dictionaryCollection.addDictionary(whitelistDictionary);
if (null == mContactsDictionary) {
mContactsDictionary = new SynchronouslyLoadedContactsDictionary(this);
}
// TODO: add a setting to use or not contacts when checking spelling
dictionaryCollection.addDictionary(mContactsDictionary);
return new DictAndProximity(dictionaryCollection, proximityInfo);
}
// This method assumes the text is not empty or null.
private static int getCapitalizationType(String text) {
// If the first char is not uppercase, then the word is either all lower case,
// and in either case we return CAPITALIZE_NONE.
if (!Character.isUpperCase(text.codePointAt(0))) return CAPITALIZE_NONE;
final int len = text.codePointCount(0, text.length());
int capsCount = 1;
for (int i = 1; i < len; ++i) {
if (1 != capsCount && i != capsCount) break;
if (Character.isUpperCase(text.codePointAt(i))) ++capsCount;
}
// We know the first char is upper case. So we want to test if either everything
// else is lower case, or if everything else is upper case. If the string is
// exactly one char long, then we will arrive here with capsCount 1, and this is
// correct, too.
if (1 == capsCount) return CAPITALIZE_FIRST;
return (len == capsCount ? CAPITALIZE_ALL : CAPITALIZE_NONE);
}
private static class AndroidSpellCheckerSession extends Session {
// Immutable, but need the locale which is not available in the constructor yet
private DictionaryPool mDictionaryPool;
// Likewise
private Locale mLocale;
private final AndroidSpellCheckerService mService;
AndroidSpellCheckerSession(final AndroidSpellCheckerService service) {
mService = service;
}
@Override
public void onCreate() {
final String localeString = getLocale();
mDictionaryPool = mService.getDictionaryPool(localeString);
mLocale = LocaleUtils.constructLocaleFromString(localeString);
}
/**
* Finds out whether a particular string should be filtered out of spell checking.
*
* This will loosely match URLs, numbers, symbols.
*
* @param text the string to evaluate.
* @return true if we should filter this text out, false otherwise
*/
private boolean shouldFilterOut(final String text) {
if (TextUtils.isEmpty(text) || text.length() <= 1) return true;
// TODO: check if an equivalent processing can't be done more quickly with a
// compiled regexp.
// Filter by first letter
final int firstCodePoint = text.codePointAt(0);
// Filter out words that don't start with a letter or an apostrophe
if (!Character.isLetter(firstCodePoint)
&& '\'' != firstCodePoint) return true;
// Filter contents
final int length = text.length();
int letterCount = 0;
for (int i = 0; i < length; ++i) {
final int codePoint = text.codePointAt(i);
// Any word containing a '@' is probably an e-mail address
// Any word containing a '/' is probably either an ad-hoc combination of two
// words or a URI - in either case we don't want to spell check that
if ('@' == codePoint
|| '/' == codePoint) return true;
if (Character.isLetter(codePoint)) ++letterCount;
}
// Guestimate heuristic: perform spell checking if at least 3/4 of the characters
// in this word are letters
return (letterCount * 4 < length * 3);
}
// Note : this must be reentrant
/**
* Gets a list of suggestions for a specific string. This returns a list of possible
* corrections for the text passed as an argument. It may split or group words, and
* even perform grammatical analysis.
*/
@Override
public SuggestionsInfo onGetSuggestions(final TextInfo textInfo,
final int suggestionsLimit) {
try {
final String text = textInfo.getText();
if (shouldFilterOut(text)) {
DictAndProximity dictInfo = null;
try {
dictInfo = mDictionaryPool.takeOrGetNull();
if (null == dictInfo) return getNotInDictEmptySuggestions();
return dictInfo.mDictionary.isValidWord(text) ? getInDictEmptySuggestions()
: getNotInDictEmptySuggestions();
} finally {
if (null != dictInfo) {
if (!mDictionaryPool.offer(dictInfo)) {
Log.e(TAG, "Can't re-insert a dictionary into its pool");
}
}
}
}
// TODO: Don't gather suggestions if the limit is <= 0 unless necessary
final SuggestionsGatherer suggestionsGatherer = new SuggestionsGatherer(text,
mService.mSuggestionThreshold, mService.mLikelyThreshold, suggestionsLimit);
final WordComposer composer = new WordComposer();
final int length = text.length();
for (int i = 0; i < length; ++i) {
final int character = text.codePointAt(i);
final int proximityIndex = SpellCheckerProximityInfo.getIndexOf(character);
final int[] proximities;
if (-1 == proximityIndex) {
proximities = new int[] { character };
} else {
proximities = Arrays.copyOfRange(SpellCheckerProximityInfo.PROXIMITY,
proximityIndex,
proximityIndex + SpellCheckerProximityInfo.ROW_SIZE);
}
composer.add(character, proximities,
WordComposer.NOT_A_COORDINATE, WordComposer.NOT_A_COORDINATE);
}
final int capitalizeType = getCapitalizationType(text);
boolean isInDict = true;
DictAndProximity dictInfo = null;
try {
dictInfo = mDictionaryPool.takeOrGetNull();
if (null == dictInfo) return getNotInDictEmptySuggestions();
dictInfo.mDictionary.getWords(composer, suggestionsGatherer,
dictInfo.mProximityInfo);
isInDict = dictInfo.mDictionary.isValidWord(text);
if (!isInDict && CAPITALIZE_NONE != capitalizeType) {
// We want to test the word again if it's all caps or first caps only.
// If it's fully down, we already tested it, if it's mixed case, we don't
// want to test a lowercase version of it.
isInDict = dictInfo.mDictionary.isValidWord(text.toLowerCase(mLocale));
}
} finally {
if (null != dictInfo) {
if (!mDictionaryPool.offer(dictInfo)) {
Log.e(TAG, "Can't re-insert a dictionary into its pool");
}
}
}
final SuggestionsGatherer.Result result = suggestionsGatherer.getResults(
capitalizeType, mLocale);
if (DBG) {
Log.i(TAG, "Spell checking results for " + text + " with suggestion limit "
+ suggestionsLimit);
Log.i(TAG, "IsInDict = " + isInDict);
Log.i(TAG, "LooksLikeTypo = " + (!isInDict));
Log.i(TAG, "HasLikelySuggestions = " + result.mHasLikelySuggestions);
if (null != result.mSuggestions) {
for (String suggestion : result.mSuggestions) {
Log.i(TAG, suggestion);
}
}
}
// TODO: actually use result.mHasLikelySuggestions
final int flags =
(isInDict ? SuggestionsInfo.RESULT_ATTR_IN_THE_DICTIONARY
: SuggestionsInfo.RESULT_ATTR_LOOKS_LIKE_TYPO);
return new SuggestionsInfo(flags, result.mSuggestions);
} catch (RuntimeException e) {
// Don't kill the keyboard if there is a bug in the spell checker
if (DBG) {
throw e;
} else {
Log.e(TAG, "Exception while spellcheking: " + e);
return getNotInDictEmptySuggestions();
}
}
}
}
}