1 /* 2 * Copyright (C) 2008 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 17 package com.android.inputmethod.latin; 18 19 import com.android.inputmethod.keyboard.ProximityInfo; 20 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo; 21 22 import java.util.ArrayList; 23 24 /** 25 * Abstract base class for a dictionary that can do a fuzzy search for words based on a set of key 26 * strokes. 27 */ 28 public abstract class Dictionary { 29 public static final int NOT_A_PROBABILITY = -1; 30 31 // The following types do not actually come from real dictionary instances, so we create 32 // corresponding instances. 33 public static final String TYPE_USER_TYPED = "user_typed"; 34 public static final Dictionary DICTIONARY_USER_TYPED = new PhonyDictionary(TYPE_USER_TYPED); 35 36 public static final String TYPE_APPLICATION_DEFINED = "application_defined"; 37 public static final Dictionary DICTIONARY_APPLICATION_DEFINED = 38 new PhonyDictionary(TYPE_APPLICATION_DEFINED); 39 40 public static final String TYPE_HARDCODED = "hardcoded"; // punctuation signs and such 41 public static final Dictionary DICTIONARY_HARDCODED = 42 new PhonyDictionary(TYPE_HARDCODED); 43 44 // Spawned by resuming suggestions. Comes from a span that was in the TextView. 45 public static final String TYPE_RESUMED = "resumed"; 46 public static final Dictionary DICTIONARY_RESUMED = 47 new PhonyDictionary(TYPE_RESUMED); 48 49 // The following types of dictionary have actual functional instances. We don't need final 50 // phony dictionary instances for them. 51 public static final String TYPE_MAIN = "main"; 52 public static final String TYPE_CONTACTS = "contacts"; 53 // User dictionary, the system-managed one. 54 public static final String TYPE_USER = "user"; 55 // User history dictionary internal to LatinIME. This assumes bigram prediction for now. 56 public static final String TYPE_USER_HISTORY = "history"; 57 // Personalization binary dictionary internal to LatinIME. 58 public static final String TYPE_PERSONALIZATION = "personalization"; 59 // Personalization prediction dictionary internal to LatinIME's Java code. 60 public static final String TYPE_PERSONALIZATION_PREDICTION_IN_JAVA = 61 "personalization_prediction_in_java"; 62 public final String mDictType; 63 64 public Dictionary(final String dictType) { 65 mDictType = dictType; 66 } 67 68 /** 69 * Searches for suggestions for a given context. For the moment the context is only the 70 * previous word. 71 * @param composer the key sequence to match with coordinate info, as a WordComposer 72 * @param prevWord the previous word, or null if none 73 * @param proximityInfo the object for key proximity. May be ignored by some implementations. 74 * @param blockOffensiveWords whether to block potentially offensive words 75 * @param additionalFeaturesOptions options about additional features used for the suggestion. 76 * @return the list of suggestions (possibly null if none) 77 */ 78 // TODO: pass more context than just the previous word, to enable better suggestions (n-gram 79 // and more) 80 abstract public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer, 81 final String prevWord, final ProximityInfo proximityInfo, 82 final boolean blockOffensiveWords, final int[] additionalFeaturesOptions); 83 84 // The default implementation of this method ignores sessionId. 85 // Subclasses that want to use sessionId need to override this method. 86 public ArrayList<SuggestedWordInfo> getSuggestionsWithSessionId(final WordComposer composer, 87 final String prevWord, final ProximityInfo proximityInfo, 88 final boolean blockOffensiveWords, final int[] additionalFeaturesOptions, 89 final int sessionId) { 90 return getSuggestions(composer, prevWord, proximityInfo, blockOffensiveWords, 91 additionalFeaturesOptions); 92 } 93 94 /** 95 * Checks if the given word occurs in the dictionary 96 * @param word the word to search for. The search should be case-insensitive. 97 * @return true if the word exists, false otherwise 98 */ 99 abstract public boolean isValidWord(final String word); 100 101 public int getFrequency(final String word) { 102 return NOT_A_PROBABILITY; 103 } 104 105 /** 106 * Compares the contents of the character array with the typed word and returns true if they 107 * are the same. 108 * @param word the array of characters that make up the word 109 * @param length the number of valid characters in the character array 110 * @param typedWord the word to compare with 111 * @return true if they are the same, false otherwise. 112 */ 113 protected boolean same(final char[] word, final int length, final String typedWord) { 114 if (typedWord.length() != length) { 115 return false; 116 } 117 for (int i = 0; i < length; i++) { 118 if (word[i] != typedWord.charAt(i)) { 119 return false; 120 } 121 } 122 return true; 123 } 124 125 /** 126 * Override to clean up any resources. 127 */ 128 public void close() { 129 // empty base implementation 130 } 131 132 /** 133 * Subclasses may override to indicate that this Dictionary is not yet properly initialized. 134 */ 135 public boolean isInitialized() { 136 return true; 137 } 138 139 /** 140 * Whether we think this suggestion should trigger an auto-commit. prevWord is the word 141 * before the suggestion, so that we can use n-gram frequencies. 142 * @param candidate The candidate suggestion, in whole (not only the first part). 143 * @return whether we should auto-commit or not. 144 */ 145 public boolean shouldAutoCommit(final SuggestedWordInfo candidate) { 146 // If we don't have support for auto-commit, or if we don't know, we return false to 147 // avoid auto-committing stuff. Implementations of the Dictionary class that know to 148 // determine whether we should auto-commit will override this. 149 return false; 150 } 151 152 /** 153 * Not a true dictionary. A placeholder used to indicate suggestions that don't come from any 154 * real dictionary. 155 */ 156 private static class PhonyDictionary extends Dictionary { 157 // This class is not publicly instantiable. 158 private PhonyDictionary(final String type) { 159 super(type); 160 } 161 162 @Override 163 public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer, 164 final String prevWord, final ProximityInfo proximityInfo, 165 final boolean blockOffensiveWords, final int[] additionalFeaturesOptions) { 166 return null; 167 } 168 169 @Override 170 public boolean isValidWord(String word) { 171 return false; 172 } 173 } 174 } 175
