LatinIME/java/src/com/android/inputmethod/latin/Dictionary.java

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/*
* Copyright (C) 2008 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;
import com.android.inputmethod.keyboard.ProximityInfo;
import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
import java.util.ArrayList;
/**
* Abstract base class for a dictionary that can do a fuzzy search for words based on a set of key
* strokes.
*/
public abstract class Dictionary {
public static final int NOT_A_PROBABILITY = -1;
public static final float NOT_A_LANGUAGE_WEIGHT = -1.0f;
// The following types do not actually come from real dictionary instances, so we create
// corresponding instances.
public static final String TYPE_USER_TYPED = "user_typed";
public static final Dictionary DICTIONARY_USER_TYPED = new PhonyDictionary(TYPE_USER_TYPED);
public static final String TYPE_APPLICATION_DEFINED = "application_defined";
public static final Dictionary DICTIONARY_APPLICATION_DEFINED =
new PhonyDictionary(TYPE_APPLICATION_DEFINED);
public static final String TYPE_HARDCODED = "hardcoded"; // punctuation signs and such
public static final Dictionary DICTIONARY_HARDCODED =
new PhonyDictionary(TYPE_HARDCODED);
// Spawned by resuming suggestions. Comes from a span that was in the TextView.
public static final String TYPE_RESUMED = "resumed";
public static final Dictionary DICTIONARY_RESUMED =
new PhonyDictionary(TYPE_RESUMED);
// The following types of dictionary have actual functional instances. We don't need final
// phony dictionary instances for them.
public static final String TYPE_MAIN = "main";
public static final String TYPE_CONTACTS = "contacts";
// User dictionary, the system-managed one.
public static final String TYPE_USER = "user";
// User history dictionary internal to LatinIME.
public static final String TYPE_USER_HISTORY = "history";
// Personalization dictionary.
public static final String TYPE_PERSONALIZATION = "personalization";
// Contextual dictionary.
public static final String TYPE_CONTEXTUAL = "contextual";
public final String mDictType;
public Dictionary(final String dictType) {
mDictType = dictType;
}
/**
* Searches for suggestions for a given context. For the moment the context is only the
* previous word.
* @param composer the key sequence to match with coordinate info, as a WordComposer
* @param prevWord the previous word, or null if none
* @param proximityInfo the object for key proximity. May be ignored by some implementations.
* @param blockOffensiveWords whether to block potentially offensive words
* @param additionalFeaturesOptions options about additional features used for the suggestion.
* @param sessionId the session id.
* @param inOutLanguageWeight the language weight used for generating suggestions.
* inOutLanguageWeight is a float array that has only one element. This can be updated when the
* different language weight is used.
* @return the list of suggestions (possibly null if none)
*/
// TODO: pass more context than just the previous word, to enable better suggestions (n-gram
// and more)
abstract public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
final String prevWord, final ProximityInfo proximityInfo,
final boolean blockOffensiveWords, final int[] additionalFeaturesOptions,
final int sessionId, final float[] inOutLanguageWeight);
/**
* Checks if the given word occurs in the dictionary
* @param word the word to search for. The search should be case-insensitive.
* @return true if the word exists, false otherwise
*/
abstract public boolean isValidWord(final String word);
public int getFrequency(final String word) {
return NOT_A_PROBABILITY;
}
/**
* Compares the contents of the character array with the typed word and returns true if they
* are the same.
* @param word the array of characters that make up the word
* @param length the number of valid characters in the character array
* @param typedWord the word to compare with
* @return true if they are the same, false otherwise.
*/
protected boolean same(final char[] word, final int length, final String typedWord) {
if (typedWord.length() != length) {
return false;
}
for (int i = 0; i < length; i++) {
if (word[i] != typedWord.charAt(i)) {
return false;
}
}
return true;
}
/**
* Override to clean up any resources.
*/
public void close() {
// empty base implementation
}
/**
* Subclasses may override to indicate that this Dictionary is not yet properly initialized.
*/
public boolean isInitialized() {
return true;
}
/**
* Whether we think this suggestion should trigger an auto-commit. prevWord is the word
* before the suggestion, so that we can use n-gram frequencies.
* @param candidate The candidate suggestion, in whole (not only the first part).
* @return whether we should auto-commit or not.
*/
public boolean shouldAutoCommit(final SuggestedWordInfo candidate) {
// If we don't have support for auto-commit, or if we don't know, we return false to
// avoid auto-committing stuff. Implementations of the Dictionary class that know to
// determine whether we should auto-commit will override this.
return false;
}
/**
* Not a true dictionary. A placeholder used to indicate suggestions that don't come from any
* real dictionary.
*/
private static class PhonyDictionary extends Dictionary {
// This class is not publicly instantiable.
private PhonyDictionary(final String type) {
super(type);
}
@Override
public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
final String prevWord, final ProximityInfo proximityInfo,
final boolean blockOffensiveWords, final int[] additionalFeaturesOptions,
final int sessionId, final float[] inOutLanguageWeight) {
return null;
}
@Override
public boolean isValidWord(String word) {
return false;
}
}
}