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diff --git a/java/src/com/android/inputmethod/latin/AutoDictionary.java b/java/src/com/android/inputmethod/latin/AutoDictionary.java
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+++ b/java/src/com/android/inputmethod/latin/AutoDictionary.java
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+/*
+ * Copyright (C) 2010 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;
+
+import java.util.HashMap;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteOpenHelper;
+import android.database.sqlite.SQLiteQueryBuilder;
+import android.provider.BaseColumns;
+import android.provider.UserDictionary.Words;
+import android.util.Log;
+
+/**
+ * Stores new words temporarily until they are promoted to the user dictionary
+ * for longevity. Words in the auto dictionary are used to determine if it's ok
+ * to accept a word that's not in the main or user dictionary. Using a new word
+ * repeatedly will promote it to the user dictionary.
+ */
+public class AutoDictionary extends ExpandableDictionary {
+    // Weight added to a user picking a new word from the suggestion strip
+    static final int FREQUENCY_FOR_PICKED = 3;
+    // Weight added to a user typing a new word that doesn't get corrected (or is reverted)
+    static final int FREQUENCY_FOR_TYPED = 1;
+    // A word that is frequently typed and gets promoted to the user dictionary, uses this
+    // frequency.
+    static final int FREQUENCY_FOR_AUTO_ADD = 250;
+    // If the user touches a typed word 2 times or more, it will become valid.
+    private static final int VALIDITY_THRESHOLD = 2 * FREQUENCY_FOR_PICKED;
+    // If the user touches a typed word 4 times or more, it will be added to the user dict.
+    private static final int PROMOTION_THRESHOLD = 4 * FREQUENCY_FOR_PICKED;
+
+    private LatinIME mIme;
+    // Locale for which this auto dictionary is storing words
+    private String mLocale;
+
+    private static final String DATABASE_NAME = "auto_dict.db";
+    private static final int DATABASE_VERSION = 1;
+
+    // These are the columns in the dictionary
+    // TODO: Consume less space by using a unique id for locale instead of the whole
+    // 2-5 character string.
+    private static final String COLUMN_ID = BaseColumns._ID;
+    private static final String COLUMN_WORD = "word";
+    private static final String COLUMN_FREQUENCY = "freq";
+    private static final String COLUMN_LOCALE = "locale";
+
+    /** Sort by descending order of frequency. */
+    public static final String DEFAULT_SORT_ORDER = COLUMN_FREQUENCY + " DESC";
+
+    /** Name of the words table in the auto_dict.db */
+    private static final String AUTODICT_TABLE_NAME = "words";
+
+    private static HashMap<String, String> sDictProjectionMap;
+
+    static {
+        sDictProjectionMap = new HashMap<String, String>();
+        sDictProjectionMap.put(COLUMN_ID, COLUMN_ID);
+        sDictProjectionMap.put(COLUMN_WORD, COLUMN_WORD);
+        sDictProjectionMap.put(COLUMN_FREQUENCY, COLUMN_FREQUENCY);
+        sDictProjectionMap.put(COLUMN_LOCALE, COLUMN_LOCALE);
+    }
+
+    private DatabaseHelper mOpenHelper;
+
+    public AutoDictionary(Context context, LatinIME ime, String locale) {
+        super(context);
+        mIme = ime;
+        mLocale = locale;
+        mOpenHelper = new DatabaseHelper(getContext());
+        if (mLocale != null && mLocale.length() > 1) {
+            loadDictionary();
+        }
+    }
+
+    @Override
+    public boolean isValidWord(CharSequence word) {
+        final int frequency = getWordFrequency(word);
+        return frequency >= VALIDITY_THRESHOLD;
+    }
+
+    public void close() {
+        mOpenHelper.close();
+    }
+
+    private void loadDictionary() {
+        // Load the words that correspond to the current input locale
+        Cursor cursor = query(COLUMN_LOCALE + "=?", new String[] { mLocale });
+        if (cursor.moveToFirst()) {
+            int wordIndex = cursor.getColumnIndex(COLUMN_WORD);
+            int frequencyIndex = cursor.getColumnIndex(COLUMN_FREQUENCY);
+            while (!cursor.isAfterLast()) {
+                String word = cursor.getString(wordIndex);
+                int frequency = cursor.getInt(frequencyIndex);
+                // Safeguard against adding really long words. Stack may overflow due
+                // to recursive lookup
+                if (word.length() < getMaxWordLength()) {
+                    super.addWord(word, frequency);
+                }
+                cursor.moveToNext();
+            }
+        }
+        cursor.close();
+    }
+
+    @Override
+    public void addWord(String word, int addFrequency) {
+        final int length = word.length();
+        // Don't add very short or very long words.
+        if (length < 2 || length > getMaxWordLength()) return;
+        if (mIme.getCurrentWord().isAutoCapitalized()) {
+            // Remove caps before adding
+            word = Character.toLowerCase(word.charAt(0)) + word.substring(1);
+        }
+        int freq = getWordFrequency(word);
+        freq = freq < 0 ? addFrequency : freq + addFrequency;
+        super.addWord(word, freq);
+        if (freq >= PROMOTION_THRESHOLD) {
+            mIme.promoteToUserDictionary(word, FREQUENCY_FOR_AUTO_ADD);
+            // Delete the word (for input locale) from the auto dictionary db, as it
+            // is now in the user dictionary provider.
+            delete(COLUMN_WORD + "=? AND " + COLUMN_LOCALE + "=?",
+                    new String[] { word, mLocale });
+        } else {
+            update(word, freq, mLocale);
+        }
+    }
+
+    /**
+     * This class helps open, create, and upgrade the database file.
+     */
+    private static class DatabaseHelper extends SQLiteOpenHelper {
+
+        DatabaseHelper(Context context) {
+            super(context, DATABASE_NAME, null, DATABASE_VERSION);
+        }
+
+        @Override
+        public void onCreate(SQLiteDatabase db) {
+            db.execSQL("CREATE TABLE " + AUTODICT_TABLE_NAME + " ("
+                    + COLUMN_ID + " INTEGER PRIMARY KEY,"
+                    + COLUMN_WORD + " TEXT,"
+                    + COLUMN_FREQUENCY + " INTEGER,"
+                    + COLUMN_LOCALE + " TEXT"
+                    + ");");
+        }
+
+        @Override
+        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            Log.w("AutoDictionary", "Upgrading database from version " + oldVersion + " to "
+                    + newVersion + ", which will destroy all old data");
+            db.execSQL("DROP TABLE IF EXISTS " + AUTODICT_TABLE_NAME);
+            onCreate(db);
+        }
+    }
+
+    private Cursor query(String selection, String[] selectionArgs) {
+        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
+        qb.setTables(AUTODICT_TABLE_NAME);
+        qb.setProjectionMap(sDictProjectionMap);
+
+        // Get the database and run the query
+        SQLiteDatabase db = mOpenHelper.getReadableDatabase();
+        Cursor c = qb.query(db, null, selection, selectionArgs, null, null,
+                DEFAULT_SORT_ORDER);
+        return c;
+    }
+
+    private boolean insert(ContentValues values) {
+        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        long rowId = db.insert(AUTODICT_TABLE_NAME, Words.WORD, values);
+        if (rowId > 0) {
+            return true;
+        }
+        return false;
+    }
+
+    private int delete(String where, String[] whereArgs) {
+        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        int count = db.delete(AUTODICT_TABLE_NAME, where, whereArgs);
+        return count;
+    }
+
+    private int update(String word, int frequency, String locale) {
+        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        long count = db.delete(AUTODICT_TABLE_NAME, COLUMN_WORD + "=? AND " + COLUMN_LOCALE + "=?",
+                new String[] { word, locale });
+        count = db.insert(AUTODICT_TABLE_NAME, null,
+                getContentValues(word, frequency, locale));
+        return (int) count;
+    }
+
+    private ContentValues getContentValues(String word, int frequency, String locale) {
+        ContentValues values = new ContentValues(4);
+        values.put(COLUMN_WORD, word);
+        values.put(COLUMN_FREQUENCY, frequency);
+        values.put(COLUMN_LOCALE, locale);
+        return values;
+    }
+}