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diff --git a/java/src/com/android/inputmethod/latin/Dictionary.java b/java/src/com/android/inputmethod/latin/Dictionary.java
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+++ b/java/src/com/android/inputmethod/latin/Dictionary.java
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+/*
+ * Copyright (C) 2008-2009 Google Inc.
+ * 
+ * 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;
+
+/**
+ * Abstract base class for a dictionary that can do a fuzzy search for words based on a set of key
+ * strokes.
+ */
+abstract public class Dictionary {
+    
+    /**
+     * Whether or not to replicate the typed word in the suggested list, even if it's valid.
+     */
+    protected static final boolean INCLUDE_TYPED_WORD_IF_VALID = false;
+    
+    /**
+     * The weight to give to a word if it's length is the same as the number of typed characters.
+     */
+    protected static final int FULL_WORD_FREQ_MULTIPLIER = 2;
+    
+    /**
+     * Interface to be implemented by classes requesting words to be fetched from the dictionary.
+     * @see #getWords(WordComposer, WordCallback)
+     */
+    public interface WordCallback {
+        /**
+         * Adds a word to a list of suggestions. The word is expected to be ordered based on
+         * the provided frequency. 
+         * @param word the character array containing the word
+         * @param wordOffset starting offset of the word in the character array
+         * @param wordLength length of valid characters in the character array
+         * @param frequency the frequency of occurence. This is normalized between 1 and 255, but
+         * can exceed those limits
+         * @return true if the word was added, false if no more words are required
+         */
+        boolean addWord(char[] word, int wordOffset, int wordLength, int frequency);
+    }
+
+    /**
+     * Searches for words in the dictionary that match the characters in the composer. Matched 
+     * words are added through the callback object.
+     * @param composer the key sequence to match
+     * @param callback the callback object to send matched words to as possible candidates
+     * @param nextLettersFrequencies array of frequencies of next letters that could follow the
+     *        word so far. For instance, "bracke" can be followed by "t", so array['t'] will have
+     *        a non-zero value on returning from this method. 
+     *        Pass in null if you don't want the dictionary to look up next letters.
+     * @see WordCallback#addWord(char[], int, int)
+     */
+    abstract public void getWords(final WordComposer composer, final WordCallback callback,
+            int[] nextLettersFrequencies);
+
+    /**
+     * 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(CharSequence word);
+    
+    /**
+     * 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 CharSequence 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() {
+    }
+}