diff --git a/java/src/com/android/inputmethod/latin/DictionaryFacilitator.java b/java/src/com/android/inputmethod/latin/DictionaryFacilitator.java
index 0f410d5..2123638 100644
--- a/java/src/com/android/inputmethod/latin/DictionaryFacilitator.java
+++ b/java/src/com/android/inputmethod/latin/DictionaryFacilitator.java
@@ -169,7 +169,7 @@
     }
 
     public DictionaryFacilitator() {
-        mDistracterFilter = new DistracterFilter();
+        mDistracterFilter = new DistracterFilter.EmptyDistracterFilter();
     }
 
     public DictionaryFacilitator(final DistracterFilter distracterFilter) {
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 5fc4058..34d5f71 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -84,7 +84,7 @@
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.CoordinateUtils;
 import com.android.inputmethod.latin.utils.DialogUtils;
-import com.android.inputmethod.latin.utils.DistracterFilter;
+import com.android.inputmethod.latin.utils.DistracterFilterUsingSuggestion;
 import com.android.inputmethod.latin.utils.ImportantNoticeUtils;
 import com.android.inputmethod.latin.utils.IntentUtils;
 import com.android.inputmethod.latin.utils.JniUtils;
@@ -125,7 +125,7 @@
 
     private final Settings mSettings;
     private final DictionaryFacilitator mDictionaryFacilitator =
-            new DictionaryFacilitator(new DistracterFilter(this /* context */));
+            new DictionaryFacilitator(new DistracterFilterUsingSuggestion(this /* context */));
     private final InputLogic mInputLogic = new InputLogic(this /* LatinIME */,
             this /* SuggestionStripViewAccessor */, mDictionaryFacilitator);
     // We expect to have only one decoder in almost all cases, hence the default capacity of 1.
diff --git a/java/src/com/android/inputmethod/latin/utils/DistracterFilter.java b/java/src/com/android/inputmethod/latin/utils/DistracterFilter.java
index 331bc50..6e0fab3 100644
--- a/java/src/com/android/inputmethod/latin/utils/DistracterFilter.java
+++ b/java/src/com/android/inputmethod/latin/utils/DistracterFilter.java
@@ -16,159 +16,14 @@
 
 package com.android.inputmethod.latin.utils;
 
-import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
-import java.util.Map;
-import java.util.concurrent.TimeUnit;
 
-import android.content.Context;
-import android.content.res.Resources;
-import android.text.InputType;
-import android.util.Log;
-import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodSubtype;
 
-import com.android.inputmethod.keyboard.Keyboard;
-import com.android.inputmethod.keyboard.KeyboardId;
-import com.android.inputmethod.keyboard.KeyboardLayoutSet;
-import com.android.inputmethod.latin.Constants;
-import com.android.inputmethod.latin.DictionaryFacilitator;
 import com.android.inputmethod.latin.PrevWordsInfo;
-import com.android.inputmethod.latin.Suggest;
-import com.android.inputmethod.latin.Suggest.OnGetSuggestedWordsCallback;
-import com.android.inputmethod.latin.SuggestedWords;
-import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
-import com.android.inputmethod.latin.WordComposer;
 
-/**
- * This class is used to prevent distracters being added to personalization
- * or user history dictionaries
- */
-public class DistracterFilter {
-    private static final String TAG = DistracterFilter.class.getSimpleName();
-
-    private static final long TIMEOUT_TO_WAIT_LOADING_DICTIONARIES_IN_SECONDS = 120;
-
-    private final Context mContext;
-    private final Map<Locale, InputMethodSubtype> mLocaleToSubtypeMap;
-    private final Map<Locale, Keyboard> mLocaleToKeyboardMap;
-    private final DictionaryFacilitator mDictionaryFacilitator;
-    private final Suggest mSuggest;
-    private Keyboard mKeyboard;
-    private final Object mLock = new Object();
-
-    // If the score of the top suggestion exceeds this value, the tested word (e.g.,
-    // an OOV, a misspelling, or an in-vocabulary word) would be considered as a distracter to
-    // words in dictionary. The greater the threshold is, the less likely the tested word would
-    // become a distracter, which means the tested word will be more likely to be added to
-    // the dictionary.
-    private static final float DISTRACTER_WORD_SCORE_THRESHOLD = 2.0f;
-
-    // Create empty distracter filter.
-    public DistracterFilter() {
-        mContext = null;
-        mLocaleToSubtypeMap = new HashMap<>();
-        mLocaleToKeyboardMap = new HashMap<>();
-        // TODO: Quit assigning null.
-        mDictionaryFacilitator = null;
-        mSuggest = null;
-        mKeyboard = null;
-    }
-
-    /**
-     * Create a DistracterFilter instance.
-     *
-     * @param context the context.
-     */
-    public DistracterFilter(final Context context) {
-        mContext = context;
-        mLocaleToSubtypeMap = new HashMap<>();
-        mLocaleToKeyboardMap = new HashMap<>();
-        mDictionaryFacilitator = new DictionaryFacilitator();
-        mSuggest = new Suggest(mDictionaryFacilitator);
-        mKeyboard = null;
-    }
-
-    public void close() {
-        if (mDictionaryFacilitator != null) {
-            mDictionaryFacilitator.closeDictionaries();
-        }
-    }
-
-    public void updateEnabledSubtypes(final List<InputMethodSubtype> enabledSubtypes) {
-        final Map<Locale, InputMethodSubtype> newLocaleToSubtypeMap = new HashMap<>();
-        if (enabledSubtypes != null) {
-            for (final InputMethodSubtype subtype : enabledSubtypes) {
-                final Locale locale = SubtypeLocaleUtils.getSubtypeLocale(subtype);
-                if (newLocaleToSubtypeMap.containsKey(locale)) {
-                    // Multiple subtypes are enabled for one locale.
-                    // TODO: Investigate what we should do for this case.
-                    continue;
-                }
-                newLocaleToSubtypeMap.put(locale, subtype);
-            }
-        }
-        if (mLocaleToSubtypeMap.equals(newLocaleToSubtypeMap)) {
-            // Enabled subtypes have not been changed.
-            return;
-        }
-        synchronized (mLock) {
-            mLocaleToSubtypeMap.clear();
-            mLocaleToSubtypeMap.putAll(newLocaleToSubtypeMap);
-            mLocaleToKeyboardMap.clear();
-        }
-    }
-
-    private static boolean suggestionExceedsDistracterThreshold(
-            final SuggestedWordInfo suggestion, final String consideredWord,
-            final float distracterThreshold) {
-        if (null != suggestion) {
-            final int suggestionScore = suggestion.mScore;
-            final float normalizedScore = BinaryDictionaryUtils.calcNormalizedScore(
-                    consideredWord, suggestion.mWord, suggestionScore);
-            if (normalizedScore > distracterThreshold) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    private void loadKeyboardForLocale(final Locale newLocale) {
-        final Keyboard cachedKeyboard = mLocaleToKeyboardMap.get(newLocale);
-        if (cachedKeyboard != null) {
-            mKeyboard = cachedKeyboard;
-            return;
-        }
-        final InputMethodSubtype subtype;
-        synchronized (mLock) {
-            subtype = mLocaleToSubtypeMap.get(newLocale);
-        }
-        if (subtype == null) {
-            return;
-        }
-        final EditorInfo editorInfo = new EditorInfo();
-        editorInfo.inputType = InputType.TYPE_CLASS_TEXT;
-        final KeyboardLayoutSet.Builder builder = new KeyboardLayoutSet.Builder(
-                mContext, editorInfo);
-        final Resources res = mContext.getResources();
-        final int keyboardWidth = ResourceUtils.getDefaultKeyboardWidth(res);
-        final int keyboardHeight = ResourceUtils.getDefaultKeyboardHeight(res);
-        builder.setKeyboardGeometry(keyboardWidth, keyboardHeight);
-        builder.setSubtype(subtype);
-        builder.setIsSpellChecker(false /* isSpellChecker */);
-        final KeyboardLayoutSet layoutSet = builder.build();
-        mKeyboard = layoutSet.getKeyboard(KeyboardId.ELEMENT_ALPHABET);
-    }
-
-    private void loadDictionariesForLocale(final Locale newlocale) throws InterruptedException {
-        mDictionaryFacilitator.resetDictionaries(mContext, newlocale,
-                false /* useContactsDict */, false /* usePersonalizedDicts */,
-                false /* forceReloadMainDictionary */, null /* listener */);
-        mDictionaryFacilitator.waitForLoadingMainDictionary(
-                TIMEOUT_TO_WAIT_LOADING_DICTIONARIES_IN_SECONDS, TimeUnit.SECONDS);
-    }
-
+public interface DistracterFilter {
     /**
      * Determine whether a word is a distracter to words in dictionaries.
      *
@@ -179,59 +34,25 @@
      * @return true if testedWord is a distracter, otherwise false.
      */
     public boolean isDistracterToWordsInDictionaries(final PrevWordsInfo prevWordsInfo,
-            final String testedWord, final Locale locale) {
-        if (mSuggest == null || locale == null) {
+            final String testedWord, final Locale locale);
+
+    public void updateEnabledSubtypes(final List<InputMethodSubtype> enabledSubtypes);
+
+    public void close();
+
+    public static final class EmptyDistracterFilter implements DistracterFilter {
+        @Override
+        public boolean isDistracterToWordsInDictionaries(PrevWordsInfo prevWordsInfo,
+                String testedWord, Locale locale) {
             return false;
         }
-        if (!locale.equals(mDictionaryFacilitator.getLocale())) {
-            synchronized (mLock) {
-                if (!mLocaleToSubtypeMap.containsKey(locale)) {
-                    Log.e(TAG, "Locale " + locale + " is not enabled.");
-                    // TODO: Investigate what we should do for disabled locales.
-                    return false;
-                }
-                loadKeyboardForLocale(locale);
-                // Reset dictionaries for the locale.
-                try {
-                    loadDictionariesForLocale(locale);
-                } catch (final InterruptedException e) {
-                    Log.e(TAG, "Interrupted while waiting for loading dicts in DistracterFilter",
-                            e);
-                    return false;
-                }
-            }
-        }
-        if (mKeyboard == null) {
-            return false;
-        }
-        final WordComposer composer = new WordComposer();
-        final int[] codePoints = StringUtils.toCodePointArray(testedWord);
-        final int[] coordinates = mKeyboard.getCoordinates(codePoints);
-        composer.setComposingWord(codePoints, coordinates, prevWordsInfo);
 
-        final int trailingSingleQuotesCount = StringUtils.getTrailingSingleQuotesCount(testedWord);
-        final String consideredWord = trailingSingleQuotesCount > 0 ?
-                testedWord.substring(0, testedWord.length() - trailingSingleQuotesCount) :
-                testedWord;
-        final AsyncResultHolder<Boolean> holder = new AsyncResultHolder<Boolean>();
-        final OnGetSuggestedWordsCallback callback = new OnGetSuggestedWordsCallback() {
-            @Override
-            public void onGetSuggestedWords(final SuggestedWords suggestedWords) {
-                if (suggestedWords != null && suggestedWords.size() > 1) {
-                    // The suggestedWordInfo at 0 is the typed word. The 1st suggestion from
-                    // the decoder is at index 1.
-                    final SuggestedWordInfo firstSuggestion = suggestedWords.getInfo(1);
-                    final boolean hasStrongDistractor = suggestionExceedsDistracterThreshold(
-                            firstSuggestion, consideredWord, DISTRACTER_WORD_SCORE_THRESHOLD);
-                    holder.set(hasStrongDistractor);
-                }
-            }
-        };
-        mSuggest.getSuggestedWords(composer, prevWordsInfo, mKeyboard.getProximityInfo(),
-                true /* blockOffensiveWords */, true /* isCorrectionEnbaled */,
-                null /* additionalFeaturesOptions */, 0 /* sessionId */,
-                SuggestedWords.NOT_A_SEQUENCE_NUMBER, callback);
+        @Override
+        public void close() {
+        }
 
-        return holder.get(false /* defaultValue */, Constants.GET_SUGGESTED_WORDS_TIMEOUT);
+        @Override
+        public void updateEnabledSubtypes(List<InputMethodSubtype> enabledSubtypes) {
+        }
     }
 }
diff --git a/java/src/com/android/inputmethod/latin/utils/DistracterFilterUsingSuggestion.java b/java/src/com/android/inputmethod/latin/utils/DistracterFilterUsingSuggestion.java
new file mode 100644
index 0000000..92033b7
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/utils/DistracterFilterUsingSuggestion.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2014 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.utils;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.text.InputType;
+import android.util.Log;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputMethodSubtype;
+
+import com.android.inputmethod.keyboard.Keyboard;
+import com.android.inputmethod.keyboard.KeyboardId;
+import com.android.inputmethod.keyboard.KeyboardLayoutSet;
+import com.android.inputmethod.latin.Constants;
+import com.android.inputmethod.latin.DictionaryFacilitator;
+import com.android.inputmethod.latin.PrevWordsInfo;
+import com.android.inputmethod.latin.Suggest;
+import com.android.inputmethod.latin.Suggest.OnGetSuggestedWordsCallback;
+import com.android.inputmethod.latin.SuggestedWords;
+import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
+import com.android.inputmethod.latin.WordComposer;
+
+/**
+ * This class is used to prevent distracters being added to personalization
+ * or user history dictionaries
+ */
+public class DistracterFilterUsingSuggestion implements DistracterFilter {
+    private static final String TAG = DistracterFilterUsingSuggestion.class.getSimpleName();
+
+    private static final long TIMEOUT_TO_WAIT_LOADING_DICTIONARIES_IN_SECONDS = 120;
+
+    private final Context mContext;
+    private final Map<Locale, InputMethodSubtype> mLocaleToSubtypeMap;
+    private final Map<Locale, Keyboard> mLocaleToKeyboardMap;
+    private final DictionaryFacilitator mDictionaryFacilitator;
+    private final Suggest mSuggest;
+    private Keyboard mKeyboard;
+    private final Object mLock = new Object();
+
+    // If the score of the top suggestion exceeds this value, the tested word (e.g.,
+    // an OOV, a misspelling, or an in-vocabulary word) would be considered as a distracter to
+    // words in dictionary. The greater the threshold is, the less likely the tested word would
+    // become a distracter, which means the tested word will be more likely to be added to
+    // the dictionary.
+    private static final float DISTRACTER_WORD_SCORE_THRESHOLD = 2.0f;
+
+    /**
+     * Create a DistracterFilter instance.
+     *
+     * @param context the context.
+     */
+    public DistracterFilterUsingSuggestion(final Context context) {
+        mContext = context;
+        mLocaleToSubtypeMap = new HashMap<>();
+        mLocaleToKeyboardMap = new HashMap<>();
+        mDictionaryFacilitator = new DictionaryFacilitator();
+        mSuggest = new Suggest(mDictionaryFacilitator);
+        mKeyboard = null;
+    }
+
+    @Override
+    public void close() {
+        mDictionaryFacilitator.closeDictionaries();
+    }
+
+    @Override
+    public void updateEnabledSubtypes(final List<InputMethodSubtype> enabledSubtypes) {
+        final Map<Locale, InputMethodSubtype> newLocaleToSubtypeMap = new HashMap<>();
+        if (enabledSubtypes != null) {
+            for (final InputMethodSubtype subtype : enabledSubtypes) {
+                final Locale locale = SubtypeLocaleUtils.getSubtypeLocale(subtype);
+                if (newLocaleToSubtypeMap.containsKey(locale)) {
+                    // Multiple subtypes are enabled for one locale.
+                    // TODO: Investigate what we should do for this case.
+                    continue;
+                }
+                newLocaleToSubtypeMap.put(locale, subtype);
+            }
+        }
+        if (mLocaleToSubtypeMap.equals(newLocaleToSubtypeMap)) {
+            // Enabled subtypes have not been changed.
+            return;
+        }
+        synchronized (mLock) {
+            mLocaleToSubtypeMap.clear();
+            mLocaleToSubtypeMap.putAll(newLocaleToSubtypeMap);
+            mLocaleToKeyboardMap.clear();
+        }
+    }
+
+    private static boolean suggestionExceedsDistracterThreshold(
+            final SuggestedWordInfo suggestion, final String consideredWord,
+            final float distracterThreshold) {
+        if (null != suggestion) {
+            final int suggestionScore = suggestion.mScore;
+            final float normalizedScore = BinaryDictionaryUtils.calcNormalizedScore(
+                    consideredWord, suggestion.mWord, suggestionScore);
+            if (normalizedScore > distracterThreshold) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void loadKeyboardForLocale(final Locale newLocale) {
+        final Keyboard cachedKeyboard = mLocaleToKeyboardMap.get(newLocale);
+        if (cachedKeyboard != null) {
+            mKeyboard = cachedKeyboard;
+            return;
+        }
+        final InputMethodSubtype subtype;
+        synchronized (mLock) {
+            subtype = mLocaleToSubtypeMap.get(newLocale);
+        }
+        if (subtype == null) {
+            return;
+        }
+        final EditorInfo editorInfo = new EditorInfo();
+        editorInfo.inputType = InputType.TYPE_CLASS_TEXT;
+        final KeyboardLayoutSet.Builder builder = new KeyboardLayoutSet.Builder(
+                mContext, editorInfo);
+        final Resources res = mContext.getResources();
+        final int keyboardWidth = ResourceUtils.getDefaultKeyboardWidth(res);
+        final int keyboardHeight = ResourceUtils.getDefaultKeyboardHeight(res);
+        builder.setKeyboardGeometry(keyboardWidth, keyboardHeight);
+        builder.setSubtype(subtype);
+        builder.setIsSpellChecker(false /* isSpellChecker */);
+        final KeyboardLayoutSet layoutSet = builder.build();
+        mKeyboard = layoutSet.getKeyboard(KeyboardId.ELEMENT_ALPHABET);
+    }
+
+    private void loadDictionariesForLocale(final Locale newlocale) throws InterruptedException {
+        mDictionaryFacilitator.resetDictionaries(mContext, newlocale,
+                false /* useContactsDict */, false /* usePersonalizedDicts */,
+                false /* forceReloadMainDictionary */, null /* listener */);
+        mDictionaryFacilitator.waitForLoadingMainDictionary(
+                TIMEOUT_TO_WAIT_LOADING_DICTIONARIES_IN_SECONDS, TimeUnit.SECONDS);
+    }
+
+    /**
+     * Determine whether a word is a distracter to words in dictionaries.
+     *
+     * @param prevWordsInfo the information of previous words.
+     * @param testedWord the word that will be tested to see whether it is a distracter to words
+     *                   in dictionaries.
+     * @param locale the locale of word.
+     * @return true if testedWord is a distracter, otherwise false.
+     */
+    @Override
+    public boolean isDistracterToWordsInDictionaries(final PrevWordsInfo prevWordsInfo,
+            final String testedWord, final Locale locale) {
+        if (locale == null) {
+            return false;
+        }
+        if (!locale.equals(mDictionaryFacilitator.getLocale())) {
+            synchronized (mLock) {
+                if (!mLocaleToSubtypeMap.containsKey(locale)) {
+                    Log.e(TAG, "Locale " + locale + " is not enabled.");
+                    // TODO: Investigate what we should do for disabled locales.
+                    return false;
+                }
+                loadKeyboardForLocale(locale);
+                // Reset dictionaries for the locale.
+                try {
+                    loadDictionariesForLocale(locale);
+                } catch (final InterruptedException e) {
+                    Log.e(TAG, "Interrupted while waiting for loading dicts in DistracterFilter",
+                            e);
+                    return false;
+                }
+            }
+        }
+        if (mKeyboard == null) {
+            return false;
+        }
+        final WordComposer composer = new WordComposer();
+        final int[] codePoints = StringUtils.toCodePointArray(testedWord);
+        final int[] coordinates = mKeyboard.getCoordinates(codePoints);
+        composer.setComposingWord(codePoints, coordinates, prevWordsInfo);
+
+        final int trailingSingleQuotesCount = StringUtils.getTrailingSingleQuotesCount(testedWord);
+        final String consideredWord = trailingSingleQuotesCount > 0 ?
+                testedWord.substring(0, testedWord.length() - trailingSingleQuotesCount) :
+                testedWord;
+        final AsyncResultHolder<Boolean> holder = new AsyncResultHolder<Boolean>();
+        final OnGetSuggestedWordsCallback callback = new OnGetSuggestedWordsCallback() {
+            @Override
+            public void onGetSuggestedWords(final SuggestedWords suggestedWords) {
+                if (suggestedWords != null && suggestedWords.size() > 1) {
+                    // The suggestedWordInfo at 0 is the typed word. The 1st suggestion from
+                    // the decoder is at index 1.
+                    final SuggestedWordInfo firstSuggestion = suggestedWords.getInfo(1);
+                    final boolean hasStrongDistractor = suggestionExceedsDistracterThreshold(
+                            firstSuggestion, consideredWord, DISTRACTER_WORD_SCORE_THRESHOLD);
+                    holder.set(hasStrongDistractor);
+                }
+            }
+        };
+        mSuggest.getSuggestedWords(composer, prevWordsInfo, mKeyboard.getProximityInfo(),
+                true /* blockOffensiveWords */, true /* isCorrectionEnbaled */,
+                null /* additionalFeaturesOptions */, 0 /* sessionId */,
+                SuggestedWords.NOT_A_SEQUENCE_NUMBER, callback);
+
+        return holder.get(false /* defaultValue */, Constants.GET_SUGGESTED_WORDS_TIMEOUT);
+    }
+}
diff --git a/tests/src/com/android/inputmethod/latin/DistracterFilterTest.java b/tests/src/com/android/inputmethod/latin/DistracterFilterTest.java
index 5631f97..ddbc8ac 100644
--- a/tests/src/com/android/inputmethod/latin/DistracterFilterTest.java
+++ b/tests/src/com/android/inputmethod/latin/DistracterFilterTest.java
@@ -20,19 +20,19 @@
 
 import android.test.suitebuilder.annotation.LargeTest;
 
-import com.android.inputmethod.latin.utils.DistracterFilter;
+import com.android.inputmethod.latin.utils.DistracterFilterUsingSuggestion;
 
 /**
  * Unit test for DistracterFilter
  */
 @LargeTest
 public class DistracterFilterTest extends InputTestsBase {
-    private DistracterFilter mDistracterFilter;
+    private DistracterFilterUsingSuggestion mDistracterFilter;
 
     @Override
     protected void setUp() throws Exception {
         super.setUp();
-        mDistracterFilter = new DistracterFilter(getContext());
+        mDistracterFilter = new DistracterFilterUsingSuggestion(getContext());
         mDistracterFilter.updateEnabledSubtypes(mLatinIME.getEnabledSubtypesForTest());
     }