1/*
2 * Copyright (C) 2010 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
17package com.android.inputmethod.latin;
18
19import android.content.Context;
20import android.text.TextUtils;
21
22import com.android.inputmethod.keyboard.Key;
23import com.android.inputmethod.keyboard.KeyDetector;
24import com.android.inputmethod.keyboard.KeyboardId;
25import com.android.inputmethod.keyboard.LatinKeyboard;
26
27import java.io.File;
28import java.util.Locale;
29
30public class SuggestHelper {
31    protected final Suggest mSuggest;
32    protected final LatinKeyboard mKeyboard;
33    private final KeyDetector mKeyDetector;
34
35    public SuggestHelper(Context context, int dictionaryId, KeyboardId keyboardId) {
36        // Use null as the locale for Suggest so as to force it to use the internal dictionary
37        // (and not try to find a dictionary provider for a specified locale)
38        mSuggest = new Suggest(context, dictionaryId, null);
39        mKeyboard = new LatinKeyboard.Builder(context).load(keyboardId).build();
40        mKeyDetector = new KeyDetector(0);
41        init();
42    }
43
44    protected SuggestHelper(final Context context, final File dictionaryPath,
45            final long startOffset, final long length, final KeyboardId keyboardId,
46            final Locale locale) {
47        mSuggest = new Suggest(context, dictionaryPath, startOffset, length, null, locale);
48        mKeyboard = new LatinKeyboard.Builder(context).load(keyboardId).build();
49        mKeyDetector = new KeyDetector(0);
50        init();
51    }
52
53    private void init() {
54        mSuggest.setCorrectionMode(Suggest.CORRECTION_FULL);
55        mKeyDetector.setKeyboard(mKeyboard, 0, 0);
56        mKeyDetector.setProximityCorrectionEnabled(true);
57        mKeyDetector.setProximityThreshold(mKeyboard.mMostCommonKeyWidth);
58    }
59
60    public void setCorrectionMode(int correctionMode) {
61        mSuggest.setCorrectionMode(correctionMode);
62    }
63
64    public boolean hasMainDictionary() {
65        return mSuggest.hasMainDictionary();
66    }
67
68    private void addKeyInfo(WordComposer word, char c) {
69        for (final Key key : mKeyboard.mKeys) {
70            if (key.mCode == c) {
71                final int x = key.mX + key.mWidth / 2;
72                final int y = key.mY + key.mHeight / 2;
73                final int[] codes = mKeyDetector.newCodeArray();
74                mKeyDetector.getKeyIndexAndNearbyCodes(x, y, codes);
75                word.add(c, codes, x, y);
76                return;
77            }
78        }
79        word.add(c, new int[] { c }, WordComposer.NOT_A_COORDINATE, WordComposer.NOT_A_COORDINATE);
80    }
81
82    protected WordComposer createWordComposer(CharSequence s) {
83        WordComposer word = new WordComposer();
84        for (int i = 0; i < s.length(); i++) {
85            final char c = s.charAt(i);
86            addKeyInfo(word, c);
87        }
88        return word;
89    }
90
91    public boolean isValidWord(CharSequence typed) {
92        return AutoCorrection.isValidWord(mSuggest.getUnigramDictionaries(),
93                typed, false);
94    }
95
96    // TODO: This may be slow, but is OK for test so far.
97    public SuggestedWords getSuggestions(CharSequence typed) {
98        return mSuggest.getSuggestions(createWordComposer(typed), null,
99                mKeyboard.getProximityInfo());
100    }
101
102    public CharSequence getFirstSuggestion(CharSequence typed) {
103        WordComposer word = createWordComposer(typed);
104        SuggestedWords suggestions = mSuggest.getSuggestions(word, null,
105                mKeyboard.getProximityInfo());
106        // Note that suggestions.getWord(0) is the word user typed.
107        return suggestions.size() > 1 ? suggestions.getWord(1) : null;
108    }
109
110    public CharSequence getAutoCorrection(CharSequence typed) {
111        WordComposer word = createWordComposer(typed);
112        SuggestedWords suggestions = mSuggest.getSuggestions(word, null,
113                mKeyboard.getProximityInfo());
114        // Note that suggestions.getWord(0) is the word user typed.
115        return (suggestions.size() > 1 && mSuggest.hasAutoCorrection())
116                ? suggestions.getWord(1) : null;
117    }
118
119    public int getSuggestIndex(CharSequence typed, CharSequence expected) {
120        WordComposer word = createWordComposer(typed);
121        SuggestedWords suggestions = mSuggest.getSuggestions(word, null,
122                mKeyboard.getProximityInfo());
123        // Note that suggestions.getWord(0) is the word user typed.
124        for (int i = 1; i < suggestions.size(); i++) {
125            if (TextUtils.equals(suggestions.getWord(i), expected))
126                return i;
127        }
128        return -1;
129    }
130
131    private void getBigramSuggestions(CharSequence previous, CharSequence typed) {
132        if (!TextUtils.isEmpty(previous) && (typed.length() > 1)) {
133            WordComposer firstChar = createWordComposer(Character.toString(typed.charAt(0)));
134            mSuggest.getSuggestions(firstChar, previous, mKeyboard.getProximityInfo());
135        }
136    }
137
138    public CharSequence getBigramFirstSuggestion(CharSequence previous, CharSequence typed) {
139        WordComposer word = createWordComposer(typed);
140        getBigramSuggestions(previous, typed);
141        SuggestedWords suggestions = mSuggest.getSuggestions(word, previous,
142                mKeyboard.getProximityInfo());
143        return suggestions.size() > 1 ? suggestions.getWord(1) : null;
144    }
145
146    public CharSequence getBigramAutoCorrection(CharSequence previous, CharSequence typed) {
147        WordComposer word = createWordComposer(typed);
148        getBigramSuggestions(previous, typed);
149        SuggestedWords suggestions = mSuggest.getSuggestions(word, previous,
150                mKeyboard.getProximityInfo());
151        return (suggestions.size() > 1 && mSuggest.hasAutoCorrection())
152                ? suggestions.getWord(1) : null;
153    }
154
155    public int searchBigramSuggestion(CharSequence previous, CharSequence typed,
156            CharSequence expected) {
157        WordComposer word = createWordComposer(typed);
158        getBigramSuggestions(previous, typed);
159        SuggestedWords suggestions = mSuggest.getSuggestions(word, previous,
160                mKeyboard.getProximityInfo());
161        for (int i = 1; i < suggestions.size(); i++) {
162            if (TextUtils.equals(suggestions.getWord(i), expected))
163                return i;
164        }
165        return -1;
166    }
167}
168