diff options
Diffstat (limited to 'java/src/com/android/inputmethod/latin/utils')
| -rw-r--r-- | java/src/com/android/inputmethod/latin/utils/AutoCorrectionUtils.java | 139 | ||||
| -rw-r--r-- | java/src/com/android/inputmethod/latin/utils/ByteArrayWrapper.java | 81 |
2 files changed, 220 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/utils/AutoCorrectionUtils.java b/java/src/com/android/inputmethod/latin/utils/AutoCorrectionUtils.java new file mode 100644 index 000000000..066c5fd32 --- /dev/null +++ b/java/src/com/android/inputmethod/latin/utils/AutoCorrectionUtils.java @@ -0,0 +1,139 @@ +/* + * 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.android.inputmethod.latin.utils; + +import com.android.inputmethod.latin.BinaryDictionary; +import com.android.inputmethod.latin.Dictionary; +import com.android.inputmethod.latin.LatinImeLogger; +import com.android.inputmethod.latin.Suggest; +import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo; + +import android.text.TextUtils; +import android.util.Log; + +import java.util.concurrent.ConcurrentHashMap; + +public final class AutoCorrectionUtils { + private static final boolean DBG = LatinImeLogger.sDBG; + private static final String TAG = AutoCorrectionUtils.class.getSimpleName(); + private static final int MINIMUM_SAFETY_NET_CHAR_LENGTH = 4; + + private AutoCorrectionUtils() { + // Purely static class: can't instantiate. + } + + public static boolean isValidWord(final Suggest suggest, final String word, + final boolean ignoreCase) { + if (TextUtils.isEmpty(word)) { + return false; + } + final ConcurrentHashMap<String, Dictionary> dictionaries = suggest.getUnigramDictionaries(); + final String lowerCasedWord = word.toLowerCase(suggest.mLocale); + for (final String key : dictionaries.keySet()) { + final Dictionary dictionary = dictionaries.get(key); + // It's unclear how realistically 'dictionary' can be null, but the monkey is somehow + // managing to get null in here. Presumably the language is changing to a language with + // no main dictionary and the monkey manages to type a whole word before the thread + // that reads the dictionary is started or something? + // Ideally the passed map would come out of a {@link java.util.concurrent.Future} and + // would be immutable once it's finished initializing, but concretely a null test is + // probably good enough for the time being. + if (null == dictionary) continue; + if (dictionary.isValidWord(word) + || (ignoreCase && dictionary.isValidWord(lowerCasedWord))) { + return true; + } + } + return false; + } + + public static int getMaxFrequency(final ConcurrentHashMap<String, Dictionary> dictionaries, + final String word) { + if (TextUtils.isEmpty(word)) { + return Dictionary.NOT_A_PROBABILITY; + } + int maxFreq = -1; + for (final String key : dictionaries.keySet()) { + final Dictionary dictionary = dictionaries.get(key); + if (null == dictionary) continue; + final int tempFreq = dictionary.getFrequency(word); + if (tempFreq >= maxFreq) { + maxFreq = tempFreq; + } + } + return maxFreq; + } + + public static boolean suggestionExceedsAutoCorrectionThreshold( + final SuggestedWordInfo suggestion, final String consideredWord, + final float autoCorrectionThreshold) { + if (null != suggestion) { + // Shortlist a whitelisted word + if (suggestion.mKind == SuggestedWordInfo.KIND_WHITELIST) return true; + final int autoCorrectionSuggestionScore = suggestion.mScore; + // TODO: when the normalized score of the first suggestion is nearly equals to + // the normalized score of the second suggestion, behave less aggressive. + final float normalizedScore = BinaryDictionary.calcNormalizedScore( + consideredWord, suggestion.mWord, autoCorrectionSuggestionScore); + if (DBG) { + Log.d(TAG, "Normalized " + consideredWord + "," + suggestion + "," + + autoCorrectionSuggestionScore + ", " + normalizedScore + + "(" + autoCorrectionThreshold + ")"); + } + if (normalizedScore >= autoCorrectionThreshold) { + if (DBG) { + Log.d(TAG, "Auto corrected by S-threshold."); + } + return !shouldBlockAutoCorrectionBySafetyNet(consideredWord, suggestion.mWord); + } + } + return false; + } + + // TODO: Resolve the inconsistencies between the native auto correction algorithms and + // this safety net + public static boolean shouldBlockAutoCorrectionBySafetyNet(final String typedWord, + final String suggestion) { + // Safety net for auto correction. + // Actually if we hit this safety net, it's a bug. + // If user selected aggressive auto correction mode, there is no need to use the safety + // net. + // If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH, + // we should not use net because relatively edit distance can be big. + final int typedWordLength = typedWord.length(); + if (typedWordLength < MINIMUM_SAFETY_NET_CHAR_LENGTH) { + return false; + } + final int maxEditDistanceOfNativeDictionary = + (typedWordLength < 5 ? 2 : typedWordLength / 2) + 1; + final int distance = BinaryDictionary.editDistance(typedWord, suggestion); + if (DBG) { + Log.d(TAG, "Autocorrected edit distance = " + distance + + ", " + maxEditDistanceOfNativeDictionary); + } + if (distance > maxEditDistanceOfNativeDictionary) { + if (DBG) { + Log.e(TAG, "Safety net: before = " + typedWord + ", after = " + suggestion); + Log.e(TAG, "(Error) The edit distance of this correction exceeds limit. " + + "Turning off auto-correction."); + } + return true; + } else { + return false; + } + } +} diff --git a/java/src/com/android/inputmethod/latin/utils/ByteArrayWrapper.java b/java/src/com/android/inputmethod/latin/utils/ByteArrayWrapper.java new file mode 100644 index 000000000..1bb27aa2b --- /dev/null +++ b/java/src/com/android/inputmethod/latin/utils/ByteArrayWrapper.java @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2013 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.utils; + +import com.android.inputmethod.latin.makedict.BinaryDictInputOutput.FusionDictionaryBufferInterface; + +/** + * This class provides an implementation for the FusionDictionary buffer interface that is backed + * by a simpled byte array. It allows to create a binary dictionary in memory. + */ +public final class ByteArrayWrapper implements FusionDictionaryBufferInterface { + private byte[] mBuffer; + private int mPosition; + + public ByteArrayWrapper(final byte[] buffer) { + mBuffer = buffer; + mPosition = 0; + } + + @Override + public int readUnsignedByte() { + return mBuffer[mPosition++] & 0xFF; + } + + @Override + public int readUnsignedShort() { + final int retval = readUnsignedByte(); + return (retval << 8) + readUnsignedByte(); + } + + @Override + public int readUnsignedInt24() { + final int retval = readUnsignedShort(); + return (retval << 8) + readUnsignedByte(); + } + + @Override + public int readInt() { + final int retval = readUnsignedShort(); + return (retval << 16) + readUnsignedShort(); + } + + @Override + public int position() { + return mPosition; + } + + @Override + public void position(int position) { + mPosition = position; + } + + @Override + public void put(final byte b) { + mBuffer[mPosition++] = b; + } + + @Override + public int limit() { + return mBuffer.length - 1; + } + + @Override + public int capacity() { + return mBuffer.length; + } +} |