UserHistoryDictionary.java revision e708b1bc2e11285ad404133b8de21719ce08acb5 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of 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,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.latin.personalization;
18
19import android.content.Context;
20
21import com.android.inputmethod.annotations.UsedForTesting;
22import com.android.inputmethod.latin.Constants;
23import com.android.inputmethod.latin.Dictionary;
24import com.android.inputmethod.latin.ExpandableBinaryDictionary;
25import com.android.inputmethod.latin.PrevWordsInfo;
26import com.android.inputmethod.latin.utils.DistracterFilter;
27
28import java.io.File;
29import java.util.Locale;
30
31/**
32 * Locally gathers stats about the words user types and various other signals like auto-correction
33 * cancellation or manual picks. This allows the keyboard to adapt to the typist over time.
34 */
35public class UserHistoryDictionary extends DecayingExpandableBinaryDictionaryBase {
36    /* package */ static final String NAME = UserHistoryDictionary.class.getSimpleName();
37
38    // TODO: Make this constructor private
39    /* package */ UserHistoryDictionary(final Context context, final Locale locale) {
40        super(context, getDictName(NAME, locale, null /* dictFile */), locale,
41                Dictionary.TYPE_USER_HISTORY, null /* dictFile */);
42    }
43
44    @UsedForTesting
45    public static UserHistoryDictionary getDictionary(final Context context, final Locale locale,
46            final File dictFile, final String dictNamePrefix) {
47        return PersonalizationHelper.getUserHistoryDictionary(context, locale);
48    }
49
50    /**
51     * Add a word to the user history dictionary.
52     *
53     * @param userHistoryDictionary the user history dictionary
54     * @param prevWordsInfo the information of previous words
55     * @param word the word the user inputted
56     * @param isValid whether the word is valid or not
57     * @param timestamp the timestamp when the word has been inputted
58     * @param distracterFilter the filter to check whether the word is a distracter
59     */
60    public static void addToDictionary(final ExpandableBinaryDictionary userHistoryDictionary,
61            final PrevWordsInfo prevWordsInfo, final String word, final boolean isValid,
62            final int timestamp, final DistracterFilter distracterFilter) {
63        final String prevWord = prevWordsInfo.mPrevWordsInfo[0].mWord;
64        if (word.length() >= Constants.DICTIONARY_MAX_WORD_LENGTH ||
65                (prevWord != null && prevWord.length() >= Constants.DICTIONARY_MAX_WORD_LENGTH)) {
66            return;
67        }
68        final int frequency = isValid ?
69                FREQUENCY_FOR_WORDS_IN_DICTS : FREQUENCY_FOR_WORDS_NOT_IN_DICTS;
70        userHistoryDictionary.addUnigramEntryWithCheckingDistracter(word, frequency,
71                null /* shortcutTarget */, 0 /* shortcutFreq */, false /* isNotAWord */,
72                false /* isBlacklisted */, timestamp, distracterFilter);
73        // Do not insert a word as a bigram of itself
74        if (word.equals(prevWord)) {
75            return;
76        }
77        if (null != prevWord) {
78            userHistoryDictionary.addNgramEntry(prevWordsInfo, word, frequency, timestamp);
79        }
80    }
81}
82