diff --git a/java/proguard.flags b/java/proguard.flags
index ac5b7df..d65924f 100644
--- a/java/proguard.flags
+++ b/java/proguard.flags
@@ -1,64 +1,11 @@
--keep class com.android.inputmethod.latin.BinaryDictionary {
-  int mDictLength;
-  <init>(...);
+# Keep classes and methods that have the @UsedForTesting annotation
+-keep @com.android.inputmethod.annotations.UsedForTesting class *
+-keepclassmembers class * {
+@com.android.inputmethod.annotations.UsedForTesting *;
 }
 
--keep class com.android.inputmethod.keyboard.ProximityInfo {
-  <init>(com.android.inputmethod.keyboard.ProximityInfo);
+# Keep classes and methods that have the @ExternallyReferenced annotation
+-keep @com.android.inputmethod.annotations.ExternallyReferenced class *
+-keepclassmembers class * {
+@com.android.inputmethod.annotations.ExternallyReferenced *;
 }
-
--keep class com.android.inputmethod.latin.Suggest {
-  <init>(...);
-  com.android.inputmethod.latin.SuggestedWords getSuggestions(...);
-}
-
--keep class com.android.inputmethod.latin.AutoCorrection {
-  java.lang.CharSequence getAutoCorrectionWord();
-}
-
--keep class com.android.inputmethod.latin.Utils {
-  boolean equalsIgnoreCase(...);
-}
-
--keep class com.android.inputmethod.latin.InputPointers {
-  *;
-}
-
--keep class com.android.inputmethod.latin.ResizableIntArray {
-  *;
-}
-
--keep class com.android.inputmethod.latin.spellcheck.SpellCheckerSettingsFragment {
-  *;
-}
-
--keep class com.android.inputmethod.keyboard.MainKeyboardView {
-  # Keep getter/setter methods for ObjectAnimator
-  int getLanguageOnSpacebarAnimAlpha();
-  void setLanguageOnSpacebarAnimAlpha(int);
-  int getAltCodeKeyWhileTypingAnimAlpha();
-  void setAltCodeKeyWhileTypingAnimAlpha(int);
-}
-
--keep class com.android.inputmethod.keyboard.MoreKeysKeyboard$Builder$MoreKeysKeyboardParams {
-  <init>(...);
-}
-
--keepclasseswithmembernames class * {
-    native <methods>;
-}
-
--keep class com.android.inputmethod.research.ResearchLogger {
-  void flush();
-  void publishCurrentLogUnit(...);
-}
-
--keep class com.android.inputmethod.keyboard.KeyboardLayoutSet$Builder {
-  void setTouchPositionCorrectionEnabled(...);
-}
-
-# The support library contains references to newer platform versions.
-# Don't warn about those in case this app is linking against an older
-# platform version.  We know about them, and they are safe.
--dontwarn android.support.v4.**
--dontwarn android.support.v13.**
diff --git a/java/src/com/android/inputmethod/annotations/ExternallyReferenced.java b/java/src/com/android/inputmethod/annotations/ExternallyReferenced.java
new file mode 100644
index 0000000..ea5f12c
--- /dev/null
+++ b/java/src/com/android/inputmethod/annotations/ExternallyReferenced.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2012 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.annotations;
+
+/**
+ * Denotes that the class, method or field should not be eliminated by ProGuard,
+ * because it is externally referenced. (See proguard.flags)
+ */
+public @interface ExternallyReferenced {
+}
diff --git a/java/src/com/android/inputmethod/annotations/UsedForTesting.java b/java/src/com/android/inputmethod/annotations/UsedForTesting.java
new file mode 100644
index 0000000..2ada091
--- /dev/null
+++ b/java/src/com/android/inputmethod/annotations/UsedForTesting.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2012 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.annotations;
+
+/**
+ * Denotes that the class, method or field should not be eliminated by ProGuard,
+ * so that unit tests can access it. (See proguard.flags)
+ */
+public @interface UsedForTesting {
+}
diff --git a/java/src/com/android/inputmethod/compat/SuggestionSpanUtils.java b/java/src/com/android/inputmethod/compat/SuggestionSpanUtils.java
index 9a89eed..c1609ea 100644
--- a/java/src/com/android/inputmethod/compat/SuggestionSpanUtils.java
+++ b/java/src/com/android/inputmethod/compat/SuggestionSpanUtils.java
@@ -83,14 +83,13 @@
     }
 
     public static CharSequence getTextWithAutoCorrectionIndicatorUnderline(
-            Context context, CharSequence text) {
+            final Context context, final String text) {
         if (TextUtils.isEmpty(text) || CONSTRUCTOR_SuggestionSpan == null
                 || OBJ_FLAG_AUTO_CORRECTION == null || OBJ_SUGGESTIONS_MAX_SIZE == null
                 || OBJ_FLAG_MISSPELLED == null || OBJ_FLAG_EASY_CORRECT == null) {
             return text;
         }
-        final Spannable spannable = text instanceof Spannable
-                ? (Spannable) text : new SpannableString(text);
+        final Spannable spannable = new SpannableString(text);
         final Object[] args =
                 { context, null, new String[] {}, (int)OBJ_FLAG_AUTO_CORRECTION,
                         (Class<?>) SuggestionSpanPickedNotificationReceiver.class };
@@ -104,8 +103,9 @@
         return spannable;
     }
 
-    public static CharSequence getTextWithSuggestionSpan(Context context,
-            CharSequence pickedWord, SuggestedWords suggestedWords, boolean dictionaryAvailable) {
+    public static CharSequence getTextWithSuggestionSpan(final Context context,
+            final String pickedWord, final SuggestedWords suggestedWords,
+            final boolean dictionaryAvailable) {
         if (!dictionaryAvailable || TextUtils.isEmpty(pickedWord)
                 || CONSTRUCTOR_SuggestionSpan == null
                 || suggestedWords.isEmpty() || suggestedWords.mIsPrediction
@@ -114,18 +114,13 @@
             return pickedWord;
         }
 
-        final Spannable spannable;
-        if (pickedWord instanceof Spannable) {
-            spannable = (Spannable) pickedWord;
-        } else {
-            spannable = new SpannableString(pickedWord);
-        }
+        final Spannable spannable = new SpannableString(pickedWord);
         final ArrayList<String> suggestionsList = CollectionUtils.newArrayList();
         for (int i = 0; i < suggestedWords.size(); ++i) {
             if (suggestionsList.size() >= OBJ_SUGGESTIONS_MAX_SIZE) {
                 break;
             }
-            final CharSequence word = suggestedWords.getWord(i);
+            final String word = suggestedWords.getWord(i);
             if (!TextUtils.equals(pickedWord, word)) {
                 suggestionsList.add(word.toString());
             }
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardActionListener.java b/java/src/com/android/inputmethod/keyboard/KeyboardActionListener.java
index 5c8f78f..e7a4e82 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardActionListener.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardActionListener.java
@@ -56,11 +56,11 @@
     public void onCodeInput(int primaryCode, int x, int y);
 
     /**
-     * Sends a sequence of characters to the listener.
+     * Sends a string of characters to the listener.
      *
-     * @param text the sequence of characters to be displayed.
+     * @param text the string of characters to be registered.
      */
-    public void onTextInput(CharSequence text);
+    public void onTextInput(String text);
 
     /**
      * Called when user started batch input.
@@ -99,7 +99,7 @@
         @Override
         public void onCodeInput(int primaryCode, int x, int y) {}
         @Override
-        public void onTextInput(CharSequence text) {}
+        public void onTextInput(String text) {}
         @Override
         public void onStartBatchInput() {}
         @Override
@@ -114,7 +114,7 @@
         }
 
         // TODO: Remove this method when the vertical correction is removed.
-        public static boolean isInvalidCoordinate(int coordinate) {
+        public static boolean isInvalidCoordinate(final int coordinate) {
             // Detect {@link Constants#NOT_A_COORDINATE},
             // {@link Constants#SUGGESTION_STRIP_COORDINATE}, and
             // {@link Constants#SPELL_CHECKER_COORDINATE}.
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardLayoutSet.java b/java/src/com/android/inputmethod/keyboard/KeyboardLayoutSet.java
index ee373e7..4d5d7e1 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardLayoutSet.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardLayoutSet.java
@@ -34,6 +34,7 @@
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodSubtype;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.compat.EditorInfoCompatUtils;
 import com.android.inputmethod.keyboard.internal.KeyboardBuilder;
 import com.android.inputmethod.keyboard.internal.KeyboardParams;
@@ -265,7 +266,7 @@
             return this;
         }
 
-        // For test only
+        @UsedForTesting
         public void disableTouchPositionCorrectionDataForTest() {
             mParams.mDisableTouchPositionCorrectionDataForTest = true;
         }
diff --git a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
index 3e6f92c..5b6820f 100644
--- a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
@@ -41,6 +41,7 @@
 
 import com.android.inputmethod.accessibility.AccessibilityUtils;
 import com.android.inputmethod.accessibility.AccessibleKeyboardViewProxy;
+import com.android.inputmethod.annotations.ExternallyReferenced;
 import com.android.inputmethod.keyboard.PointerTracker.DrawingProxy;
 import com.android.inputmethod.keyboard.PointerTracker.TimerProxy;
 import com.android.inputmethod.keyboard.internal.KeyDrawParams;
@@ -417,20 +418,23 @@
         return animator;
     }
 
-    // Getter/setter methods for {@link ObjectAnimator}.
+    @ExternallyReferenced
     public int getLanguageOnSpacebarAnimAlpha() {
         return mLanguageOnSpacebarAnimAlpha;
     }
 
+    @ExternallyReferenced
     public void setLanguageOnSpacebarAnimAlpha(final int alpha) {
         mLanguageOnSpacebarAnimAlpha = alpha;
         invalidateKey(mSpaceKey);
     }
 
+    @ExternallyReferenced
     public int getAltCodeKeyWhileTypingAnimAlpha() {
         return mAltCodeKeyWhileTypingAnimAlpha;
     }
 
+    @ExternallyReferenced
     public void setAltCodeKeyWhileTypingAnimAlpha(final int alpha) {
         mAltCodeKeyWhileTypingAnimAlpha = alpha;
         updateAltCodeKeyWhileTyping();
diff --git a/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboard.java b/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboard.java
index d7d4be4..3826a39 100644
--- a/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboard.java
+++ b/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboard.java
@@ -20,6 +20,7 @@
 import android.graphics.drawable.Drawable;
 import android.view.View;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.internal.KeyboardBuilder;
 import com.android.inputmethod.keyboard.internal.KeyboardIconsSet;
 import com.android.inputmethod.keyboard.internal.KeyboardParams;
@@ -39,7 +40,7 @@
         return mDefaultKeyCoordX;
     }
 
-    /* package for test */
+    @UsedForTesting
     static class MoreKeysKeyboardParams extends KeyboardParams {
         public boolean mIsFixedOrder;
         /* package */int mTopRowAdjustment;
diff --git a/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboardView.java b/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboardView.java
index a506176..9c450e9 100644
--- a/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/MoreKeysKeyboardView.java
@@ -48,7 +48,7 @@
     private final KeyboardActionListener mMoreKeysKeyboardListener =
             new KeyboardActionListener.Adapter() {
         @Override
-        public void onCodeInput(int primaryCode, int x, int y) {
+        public void onCodeInput(final int primaryCode, final int x, final int y) {
             // Because a more keys keyboard doesn't need proximity characters correction, we don't
             // send touch event coordinates.
             mListener.onCodeInput(
@@ -56,7 +56,7 @@
         }
 
         @Override
-        public void onTextInput(CharSequence text) {
+        public void onTextInput(final String text) {
             mListener.onTextInput(text);
         }
 
@@ -66,12 +66,12 @@
         }
 
         @Override
-        public void onUpdateBatchInput(InputPointers batchPointers) {
+        public void onUpdateBatchInput(final InputPointers batchPointers) {
             mListener.onUpdateBatchInput(batchPointers);
         }
 
         @Override
-        public void onEndBatchInput(InputPointers batchPointers) {
+        public void onEndBatchInput(final InputPointers batchPointers) {
             mListener.onEndBatchInput(batchPointers);
         }
 
@@ -81,21 +81,22 @@
         }
 
         @Override
-        public void onPressKey(int primaryCode) {
+        public void onPressKey(final int primaryCode) {
             mListener.onPressKey(primaryCode);
         }
 
         @Override
-        public void onReleaseKey(int primaryCode, boolean withSliding) {
+        public void onReleaseKey(final int primaryCode, final boolean withSliding) {
             mListener.onReleaseKey(primaryCode, withSliding);
         }
     };
 
-    public MoreKeysKeyboardView(Context context, AttributeSet attrs) {
+    public MoreKeysKeyboardView(final Context context, final AttributeSet attrs) {
         this(context, attrs, R.attr.moreKeysKeyboardViewStyle);
     }
 
-    public MoreKeysKeyboardView(Context context, AttributeSet attrs, int defStyle) {
+    public MoreKeysKeyboardView(final Context context, final AttributeSet attrs,
+            final int defStyle) {
         super(context, attrs, defStyle);
 
         final Resources res = context.getResources();
@@ -105,7 +106,7 @@
     }
 
     @Override
-    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+    protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
         final Keyboard keyboard = getKeyboard();
         if (keyboard != null) {
             final int width = keyboard.mOccupiedWidth + getPaddingLeft() + getPaddingRight();
@@ -117,7 +118,7 @@
     }
 
     @Override
-    public void setKeyboard(Keyboard keyboard) {
+    public void setKeyboard(final Keyboard keyboard) {
         super.setKeyboard(keyboard);
         mKeyDetector.setKeyboard(keyboard, -getPaddingLeft(),
                 -getPaddingTop() + mVerticalCorrection);
@@ -144,15 +145,16 @@
     }
 
     @Override
-    public void setKeyPreviewPopupEnabled(boolean previewEnabled, int delay) {
+    public void setKeyPreviewPopupEnabled(final boolean previewEnabled, final int delay) {
         // More keys keyboard needs no pop-up key preview displayed, so we pass always false with a
         // delay of 0. The delay does not matter actually since the popup is not shown anyway.
         super.setKeyPreviewPopupEnabled(false, 0);
     }
 
     @Override
-    public void showMoreKeysPanel(View parentView, Controller controller, int pointX, int pointY,
-            PopupWindow window, KeyboardActionListener listener) {
+    public void showMoreKeysPanel(final View parentView, final Controller controller,
+            final int pointX, final int pointY, final PopupWindow window,
+            final KeyboardActionListener listener) {
         mController = controller;
         mListener = listener;
         final View container = (View)getParent();
@@ -185,12 +187,12 @@
     }
 
     @Override
-    public int translateX(int x) {
+    public int translateX(final int x) {
         return x - mOriginX;
     }
 
     @Override
-    public int translateY(int y) {
+    public int translateY(final int y) {
         return y - mOriginY;
     }
 }
diff --git a/java/src/com/android/inputmethod/keyboard/internal/KeyboardBuilder.java b/java/src/com/android/inputmethod/keyboard/internal/KeyboardBuilder.java
index b314a37..3634268 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/KeyboardBuilder.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/KeyboardBuilder.java
@@ -27,6 +27,7 @@
 import android.util.Xml;
 import android.view.InflateException;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.Key;
 import com.android.inputmethod.keyboard.Keyboard;
 import com.android.inputmethod.keyboard.KeyboardId;
@@ -177,7 +178,7 @@
         return this;
     }
 
-    // For test only
+    @UsedForTesting
     public void disableTouchPositionCorrectionDataForTest() {
         mParams.mTouchPositionCorrection.setEnabled(false);
     }
diff --git a/java/src/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.java b/java/src/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.java
index 3b7c6ad..c3875ac 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.java
@@ -19,6 +19,7 @@
 import android.content.Context;
 import android.content.res.Resources;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.CollectionUtils;
 import com.android.inputmethod.latin.R;
 
@@ -64,7 +65,7 @@
         loadStringResourcesInternal(context, RESOURCE_NAMES, R.string.english_ime_name);
     }
 
-    /* package for test */
+    @UsedForTesting
     void loadStringResourcesInternal(Context context, final String[] resourceNames,
             int referenceId) {
         final Resources res = context.getResources();
diff --git a/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java b/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
index d8950a7..d7a2b6f 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
@@ -16,6 +16,7 @@
 
 package com.android.inputmethod.keyboard.internal;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.LatinImeLogger;
 
 public final class TouchPositionCorrection {
@@ -66,7 +67,7 @@
         }
     }
 
-    // For test only
+    @UsedForTesting
     public void setEnabled(final boolean enabled) {
         mEnabled = enabled;
     }
diff --git a/java/src/com/android/inputmethod/latin/AutoCorrection.java b/java/src/com/android/inputmethod/latin/AutoCorrection.java
index 84fad15..fa35922 100644
--- a/java/src/com/android/inputmethod/latin/AutoCorrection.java
+++ b/java/src/com/android/inputmethod/latin/AutoCorrection.java
@@ -33,11 +33,11 @@
     }
 
     public static boolean isValidWord(final ConcurrentHashMap<String, Dictionary> dictionaries,
-            CharSequence word, boolean ignoreCase) {
+            final String word, final boolean ignoreCase) {
         if (TextUtils.isEmpty(word)) {
             return false;
         }
-        final CharSequence lowerCasedWord = word.toString().toLowerCase();
+        final String lowerCasedWord = word.toLowerCase();
         for (final String key : dictionaries.keySet()) {
             final Dictionary dictionary = dictionaries.get(key);
             // It's unclear how realistically 'dictionary' can be null, but the monkey is somehow
@@ -57,7 +57,7 @@
     }
 
     public static int getMaxFrequency(final ConcurrentHashMap<String, Dictionary> dictionaries,
-            CharSequence word) {
+            final String word) {
         if (TextUtils.isEmpty(word)) {
             return Dictionary.NOT_A_PROBABILITY;
         }
@@ -76,12 +76,13 @@
     // Returns true if this is in any of the dictionaries.
     public static boolean isInTheDictionary(
             final ConcurrentHashMap<String, Dictionary> dictionaries,
-            final CharSequence word, final boolean ignoreCase) {
+            final String word, final boolean ignoreCase) {
         return isValidWord(dictionaries, word, ignoreCase);
     }
 
-    public static boolean suggestionExceedsAutoCorrectionThreshold(SuggestedWordInfo suggestion,
-            CharSequence consideredWord, float autoCorrectionThreshold) {
+    public static boolean suggestionExceedsAutoCorrectionThreshold(
+            final SuggestedWordInfo suggestion, final String consideredWord,
+            final float autoCorrectionThreshold) {
         if (null != suggestion) {
             // Shortlist a whitelisted word
             if (suggestion.mKind == SuggestedWordInfo.KIND_WHITELIST) return true;
@@ -89,8 +90,7 @@
             // TODO: when the normalized score of the first suggestion is nearly equals to
             //       the normalized score of the second suggestion, behave less aggressive.
             final float normalizedScore = BinaryDictionary.calcNormalizedScore(
-                    consideredWord.toString(), suggestion.mWord.toString(),
-                    autoCorrectionSuggestionScore);
+                    consideredWord, suggestion.mWord, autoCorrectionSuggestionScore);
             if (DBG) {
                 Log.d(TAG, "Normalized " + consideredWord + "," + suggestion + ","
                         + autoCorrectionSuggestionScore + ", " + normalizedScore
@@ -100,8 +100,7 @@
                 if (DBG) {
                     Log.d(TAG, "Auto corrected by S-threshold.");
                 }
-                return !shouldBlockAutoCorrectionBySafetyNet(consideredWord.toString(),
-                        suggestion.mWord);
+                return !shouldBlockAutoCorrectionBySafetyNet(consideredWord, suggestion.mWord);
             }
         }
         return false;
@@ -110,7 +109,7 @@
     // TODO: Resolve the inconsistencies between the native auto correction algorithms and
     // this safety net
     public static boolean shouldBlockAutoCorrectionBySafetyNet(final String typedWord,
-            final CharSequence suggestion) {
+            final String suggestion) {
         // Safety net for auto correction.
         // Actually if we hit this safety net, it's a bug.
         // If user selected aggressive auto correction mode, there is no need to use the safety
@@ -123,7 +122,7 @@
         }
         final int maxEditDistanceOfNativeDictionary =
                 (typedWordLength < 5 ? 2 : typedWordLength / 2) + 1;
-        final int distance = BinaryDictionary.editDistance(typedWord, suggestion.toString());
+        final int distance = BinaryDictionary.editDistance(typedWord, suggestion);
         if (DBG) {
             Log.d(TAG, "Autocorrected edit distance = " + distance
                     + ", " + maxEditDistanceOfNativeDictionary);
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 9c48aa1..80af4b9 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -64,7 +64,7 @@
 
     // TODO: There should be a way to remove used DicTraverseSession objects from
     // {@code mDicTraverseSessions}.
-    private DicTraverseSession getTraverseSession(int traverseSessionId) {
+    private DicTraverseSession getTraverseSession(final int traverseSessionId) {
         synchronized(mDicTraverseSessions) {
             DicTraverseSession traverseSession = mDicTraverseSessions.get(traverseSessionId);
             if (traverseSession == null) {
@@ -81,7 +81,6 @@
     /**
      * Constructor for the binary dictionary. This is supposed to be called from the
      * dictionary factory.
-     * All implementations should pass null into flagArray, except for testing purposes.
      * @param context the context to access the environment from.
      * @param filename the name of the file to read through native code.
      * @param offset the offset of the dictionary data within the file.
@@ -116,26 +115,27 @@
     private static native int editDistanceNative(char[] before, char[] after);
 
     // TODO: Move native dict into session
-    private final void loadDictionary(String path, long startOffset, long length) {
+    private final void loadDictionary(final String path, final long startOffset,
+            final long length) {
         mNativeDict = openNative(path, startOffset, length, FULL_WORD_SCORE_MULTIPLIER,
                 MAX_WORD_LENGTH, MAX_WORDS, MAX_PREDICTIONS);
     }
 
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo) {
+            final String prevWord, final ProximityInfo proximityInfo) {
         return getSuggestionsWithSessionId(composer, prevWord, proximityInfo, 0);
     }
 
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestionsWithSessionId(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo, int sessionId) {
+            final String prevWord, final ProximityInfo proximityInfo, int sessionId) {
         if (!isValidDictionary()) return null;
 
         Arrays.fill(mInputCodePoints, Constants.NOT_A_CODE);
         // TODO: toLowerCase in the native code
         final int[] prevWordCodePointArray = (null == prevWord)
-                ? null : StringUtils.toCodePointArray(prevWord.toString());
+                ? null : StringUtils.toCodePointArray(prevWord);
         final int composerSize = composer.size();
 
         final boolean isGesture = composer.isBatchMode();
@@ -174,15 +174,16 @@
         return suggestions;
     }
 
-    /* package for test */ boolean isValidDictionary() {
+    public boolean isValidDictionary() {
         return mNativeDict != 0;
     }
 
-    public static float calcNormalizedScore(String before, String after, int score) {
+    public static float calcNormalizedScore(final String before, final String after,
+            final int score) {
         return calcNormalizedScoreNative(before.toCharArray(), after.toCharArray(), score);
     }
 
-    public static int editDistance(String before, String after) {
+    public static int editDistance(final String before, final String after) {
         if (before == null || after == null) {
             throw new IllegalArgumentException();
         }
@@ -190,23 +191,23 @@
     }
 
     @Override
-    public boolean isValidWord(CharSequence word) {
+    public boolean isValidWord(final String word) {
         return getFrequency(word) >= 0;
     }
 
     @Override
-    public int getFrequency(CharSequence word) {
+    public int getFrequency(final String word) {
         if (word == null) return -1;
-        int[] codePoints = StringUtils.toCodePointArray(word.toString());
+        int[] codePoints = StringUtils.toCodePointArray(word);
         return getFrequencyNative(mNativeDict, codePoints);
     }
 
     // TODO: Add a batch process version (isValidBigramMultiple?) to avoid excessive numbers of jni
     // calls when checking for changes in an entire dictionary.
-    public boolean isValidBigram(CharSequence word1, CharSequence word2) {
+    public boolean isValidBigram(final String word1, final String word2) {
         if (TextUtils.isEmpty(word1) || TextUtils.isEmpty(word2)) return false;
-        int[] chars1 = StringUtils.toCodePointArray(word1.toString());
-        int[] chars2 = StringUtils.toCodePointArray(word2.toString());
+        final int[] chars1 = StringUtils.toCodePointArray(word1);
+        final int[] chars2 = StringUtils.toCodePointArray(word2);
         return isValidBigramNative(mNativeDict, chars1, chars2);
     }
 
diff --git a/java/src/com/android/inputmethod/latin/ContactsBinaryDictionary.java b/java/src/com/android/inputmethod/latin/ContactsBinaryDictionary.java
index 5edc431..7c04480 100644
--- a/java/src/com/android/inputmethod/latin/ContactsBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ContactsBinaryDictionary.java
@@ -62,7 +62,7 @@
      */
     private final boolean mUseFirstLastBigrams;
 
-    public ContactsBinaryDictionary(final Context context, Locale locale) {
+    public ContactsBinaryDictionary(final Context context, final Locale locale) {
         super(context, getFilenameWithLocale(NAME, locale.toString()), Dictionary.TYPE_CONTACTS);
         mLocale = locale;
         mUseFirstLastBigrams = useFirstLastBigramsForLocale(locale);
@@ -120,7 +120,7 @@
         }
     }
 
-    private boolean useFirstLastBigramsForLocale(Locale locale) {
+    private boolean useFirstLastBigramsForLocale(final Locale locale) {
         // TODO: Add firstname/lastname bigram rules for other languages.
         if (locale != null && locale.getLanguage().equals(Locale.ENGLISH.getLanguage())) {
             return true;
@@ -128,7 +128,7 @@
         return false;
     }
 
-    private void addWords(Cursor cursor) {
+    private void addWords(final Cursor cursor) {
         clearFusionDictionary();
         int count = 0;
         while (!cursor.isAfterLast() && count < MAX_CONTACT_COUNT) {
@@ -160,7 +160,7 @@
      * Adds the words in a name (e.g., firstname/lastname) to the binary dictionary along with their
      * bigrams depending on locale.
      */
-    private void addName(String name) {
+    private void addName(final String name) {
         int len = StringUtils.codePointCount(name);
         String prevWord = null;
         // TODO: Better tokenization for non-Latin writing systems
@@ -188,7 +188,8 @@
     /**
      * Returns the index of the last letter in the word, starting from position startIndex.
      */
-    private static int getWordEndPosition(String string, int len, int startIndex) {
+    private static int getWordEndPosition(final String string, final int len,
+            final int startIndex) {
         int end;
         int cp = 0;
         for (end = startIndex + 1; end < len; end += Character.charCount(cp)) {
@@ -249,7 +250,7 @@
         return false;
     }
 
-    private static boolean isValidName(String name) {
+    private static boolean isValidName(final String name) {
         if (name != null && -1 == name.indexOf('@')) {
             return true;
         }
@@ -259,7 +260,7 @@
     /**
      * Checks if the words in a name are in the current binary dictionary.
      */
-    private boolean isNameInDictionary(String name) {
+    private boolean isNameInDictionary(final String name) {
         int len = StringUtils.codePointCount(name);
         String prevWord = null;
         for (int i = 0; i < len; i++) {
diff --git a/java/src/com/android/inputmethod/latin/Dictionary.java b/java/src/com/android/inputmethod/latin/Dictionary.java
index 88d0c09..8207bc4 100644
--- a/java/src/com/android/inputmethod/latin/Dictionary.java
+++ b/java/src/com/android/inputmethod/latin/Dictionary.java
@@ -59,12 +59,12 @@
     // 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 CharSequence prevWord, final ProximityInfo proximityInfo);
+            final String prevWord, final ProximityInfo proximityInfo);
 
     // The default implementation of this method ignores sessionId.
     // Subclasses that want to use sessionId need to override this method.
     public ArrayList<SuggestedWordInfo> getSuggestionsWithSessionId(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo, int sessionId) {
+            final String prevWord, final ProximityInfo proximityInfo, final int sessionId) {
         return getSuggestions(composer, prevWord, proximityInfo);
     }
 
@@ -73,9 +73,9 @@
      * @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);
+    abstract public boolean isValidWord(final String word);
 
-    public int getFrequency(CharSequence word) {
+    public int getFrequency(final String word) {
         return NOT_A_PROBABILITY;
     }
 
@@ -87,7 +87,7 @@
      * @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) {
+    protected boolean same(final char[] word, final int length, final String typedWord) {
         if (typedWord.length() != length) {
             return false;
         }
diff --git a/java/src/com/android/inputmethod/latin/DictionaryCollection.java b/java/src/com/android/inputmethod/latin/DictionaryCollection.java
index d3b1209..7f78ac8 100644
--- a/java/src/com/android/inputmethod/latin/DictionaryCollection.java
+++ b/java/src/com/android/inputmethod/latin/DictionaryCollection.java
@@ -56,7 +56,7 @@
 
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo) {
+            final String prevWord, final ProximityInfo proximityInfo) {
         final CopyOnWriteArrayList<Dictionary> dictionaries = mDictionaries;
         if (dictionaries.isEmpty()) return null;
         // To avoid creating unnecessary objects, we get the list out of the first
@@ -74,14 +74,14 @@
     }
 
     @Override
-    public boolean isValidWord(CharSequence word) {
+    public boolean isValidWord(final String word) {
         for (int i = mDictionaries.size() - 1; i >= 0; --i)
             if (mDictionaries.get(i).isValidWord(word)) return true;
         return false;
     }
 
     @Override
-    public int getFrequency(CharSequence word) {
+    public int getFrequency(final String word) {
         int maxFreq = -1;
         for (int i = mDictionaries.size() - 1; i >= 0; --i) {
             final int tempFreq = mDictionaries.get(i).getFrequency(word);
diff --git a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
index b93c17f..159867a 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
@@ -198,7 +198,7 @@
 
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo) {
+            final String prevWord, final ProximityInfo proximityInfo) {
         asyncReloadDictionaryIfRequired();
         if (mLocalDictionaryController.tryLock()) {
             try {
@@ -213,12 +213,12 @@
     }
 
     @Override
-    public boolean isValidWord(final CharSequence word) {
+    public boolean isValidWord(final String word) {
         asyncReloadDictionaryIfRequired();
         return isValidWordInner(word);
     }
 
-    protected boolean isValidWordInner(final CharSequence word) {
+    protected boolean isValidWordInner(final String word) {
         if (mLocalDictionaryController.tryLock()) {
             try {
                 return isValidWordLocked(word);
@@ -229,17 +229,17 @@
         return false;
     }
 
-    protected boolean isValidWordLocked(final CharSequence word) {
+    protected boolean isValidWordLocked(final String word) {
         if (mBinaryDictionary == null) return false;
         return mBinaryDictionary.isValidWord(word);
     }
 
-    protected boolean isValidBigram(final CharSequence word1, final CharSequence word2) {
+    protected boolean isValidBigram(final String word1, final String word2) {
         if (mBinaryDictionary == null) return false;
         return mBinaryDictionary.isValidBigram(word1, word2);
     }
 
-    protected boolean isValidBigramInner(final CharSequence word1, final CharSequence word2) {
+    protected boolean isValidBigramInner(final String word1, final String word2) {
         if (mLocalDictionaryController.tryLock()) {
             try {
                 return isValidBigramLocked(word1, word2);
@@ -250,7 +250,7 @@
         return false;
     }
 
-    protected boolean isValidBigramLocked(final CharSequence word1, final CharSequence word2) {
+    protected boolean isValidBigramLocked(final String word1, final String word2) {
         if (mBinaryDictionary == null) return false;
         return mBinaryDictionary.isValidBigram(word1, word2);
     }
diff --git a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
index 8cdc2a0..c6a8103 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
@@ -69,7 +69,7 @@
             mData = new Node[INCREMENT];
         }
 
-        void add(Node n) {
+        void add(final Node n) {
             if (mLength + 1 > mData.length) {
                 Node[] tempData = new Node[mLength + INCREMENT];
                 if (mLength > 0) {
@@ -172,7 +172,7 @@
         }
     }
 
-    public void setRequiresReload(boolean reload) {
+    public void setRequiresReload(final boolean reload) {
         synchronized (mUpdatingLock) {
             mRequiresReload = reload;
         }
@@ -202,8 +202,8 @@
         addWordRec(mRoots, word, 0, shortcutTarget, frequency, null);
     }
 
-    private void addWordRec(NodeArray children, final String word, final int depth,
-            final String shortcutTarget, final int frequency, Node parentNode) {
+    private void addWordRec(final NodeArray children, final String word, final int depth,
+            final String shortcutTarget, final int frequency, final Node parentNode) {
         final int wordLength = word.length();
         if (wordLength <= depth) return;
         final char c = word.charAt(depth);
@@ -248,7 +248,7 @@
 
     @Override
     public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo) {
+            final String prevWord, final ProximityInfo proximityInfo) {
         if (reloadDictionaryIfRequired()) return null;
         if (composer.size() > 1) {
             if (composer.size() >= BinaryDictionary.MAX_WORD_LENGTH) {
@@ -267,8 +267,7 @@
 
     // This reloads the dictionary if required, and returns whether it's currently updating its
     // contents or not.
-    // @VisibleForTesting
-    boolean reloadDictionaryIfRequired() {
+    private boolean reloadDictionaryIfRequired() {
         synchronized (mUpdatingLock) {
             // If we need to update, start off a background task
             if (mRequiresReload) startDictionaryLoadingTaskLocked();
@@ -277,7 +276,7 @@
     }
 
     protected ArrayList<SuggestedWordInfo> getWordsInner(final WordComposer codes,
-            final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo) {
+            final String prevWordForBigrams, final ProximityInfo proximityInfo) {
         final ArrayList<SuggestedWordInfo> suggestions = CollectionUtils.newArrayList();
         mInputLength = codes.size();
         if (mCodes.length < mInputLength) mCodes = new int[mInputLength][];
@@ -305,7 +304,7 @@
     }
 
     @Override
-    public synchronized boolean isValidWord(CharSequence word) {
+    public synchronized boolean isValidWord(final String word) {
         synchronized (mUpdatingLock) {
             // If we need to update, start off a background task
             if (mRequiresReload) startDictionaryLoadingTaskLocked();
@@ -320,7 +319,7 @@
         return (node == null) ? false : !node.mShortcutOnly;
     }
 
-    protected boolean removeBigram(String word1, String word2) {
+    protected boolean removeBigram(final String word1, final String word2) {
         // Refer to addOrSetBigram() about word1.toLowerCase()
         final Node firstWord = searchWord(mRoots, word1.toLowerCase(), 0, null);
         final Node secondWord = searchWord(mRoots, word2, 0, null);
@@ -345,13 +344,13 @@
     /**
      * Returns the word's frequency or -1 if not found
      */
-    protected int getWordFrequency(CharSequence word) {
+    protected int getWordFrequency(final String word) {
         // Case-sensitive search
         final Node node = searchNode(mRoots, word, 0, word.length());
         return (node == null) ? -1 : node.mFrequency;
     }
 
-    protected NextWord getBigramWord(String word1, String word2) {
+    protected NextWord getBigramWord(final String word1, final String word2) {
         // Refer to addOrSetBigram() about word1.toLowerCase()
         final Node firstWord = searchWord(mRoots, word1.toLowerCase(), 0, null);
         final Node secondWord = searchWord(mRoots, word2, 0, null);
@@ -368,7 +367,8 @@
         return null;
     }
 
-    private static int computeSkippedWordFinalFreq(int freq, int snr, int inputLength) {
+    private static int computeSkippedWordFinalFreq(final int freq, final int snr,
+            final int inputLength) {
         // The computation itself makes sense for >= 2, but the == 2 case returns 0
         // anyway so we may as well test against 3 instead and return the constant
         if (inputLength >= 3) {
@@ -431,9 +431,9 @@
      * @param suggestions the list in which to add suggestions
      */
     // TODO: Share this routine with the native code for BinaryDictionary
-    protected void getWordsRec(NodeArray roots, final WordComposer codes, final char[] word,
-            final int depth, final boolean completion, int snr, int inputIndex, int skipPos,
-            final ArrayList<SuggestedWordInfo> suggestions) {
+    protected void getWordsRec(final NodeArray roots, final WordComposer codes, final char[] word,
+            final int depth, final boolean completion, final int snr, final int inputIndex,
+            final int skipPos, final ArrayList<SuggestedWordInfo> suggestions) {
         final int count = roots.mLength;
         final int codeSize = mInputLength;
         // Optimization: Prune out words that are too long compared to how much was typed.
@@ -524,11 +524,13 @@
         }
     }
 
-    public int setBigramAndGetFrequency(String word1, String word2, int frequency) {
+    public int setBigramAndGetFrequency(final String word1, final String word2,
+            final int frequency) {
         return setBigramAndGetFrequency(word1, word2, frequency, null /* unused */);
     }
 
-    public int setBigramAndGetFrequency(String word1, String word2, ForgettingCurveParams fcp) {
+    public int setBigramAndGetFrequency(final String word1, final String word2,
+            final ForgettingCurveParams fcp) {
         return setBigramAndGetFrequency(word1, word2, 0 /* unused */, fcp);
     }
 
@@ -540,8 +542,8 @@
      * @param fcp an instance of ForgettingCurveParams to use for decay policy
      * @return returns the final bigram frequency
      */
-    private int setBigramAndGetFrequency(
-            String word1, String word2, int frequency, ForgettingCurveParams fcp) {
+    private int setBigramAndGetFrequency(final String word1, final String word2,
+            final int frequency, final ForgettingCurveParams fcp) {
         // We don't want results to be different according to case of the looked up left hand side
         // word. We do want however to return the correct case for the right hand side.
         // So we want to squash the case of the left hand side, and preserve that of the right
@@ -572,7 +574,8 @@
      * Searches for the word and add the word if it does not exist.
      * @return Returns the terminal node of the word we are searching for.
      */
-    private Node searchWord(NodeArray children, String word, int depth, Node parentNode) {
+    private Node searchWord(final NodeArray children, final String word, final int depth,
+            final Node parentNode) {
         final int wordLength = word.length();
         final char c = word.charAt(depth);
         // Does children have the current character?
@@ -602,36 +605,17 @@
         return searchWord(childNode.mChildren, word, depth + 1, childNode);
     }
 
-    private void runBigramReverseLookUp(final CharSequence previousWord,
+    private void runBigramReverseLookUp(final String previousWord,
             final ArrayList<SuggestedWordInfo> suggestions) {
         // Search for the lowercase version of the word only, because that's where bigrams
         // store their sons.
-        Node prevWord = searchNode(mRoots, previousWord.toString().toLowerCase(), 0,
+        final Node prevWord = searchNode(mRoots, previousWord.toLowerCase(), 0,
                 previousWord.length());
         if (prevWord != null && prevWord.mNGrams != null) {
             reverseLookUp(prevWord.mNGrams, suggestions);
         }
     }
 
-    /**
-     * Used for testing purposes and in the spell checker
-     * This function will wait for loading from database to be done
-     */
-    void waitForDictionaryLoading() {
-        while (mUpdatingDictionary) {
-            try {
-                Thread.sleep(100);
-            } catch (InterruptedException e) {
-                //
-            }
-        }
-    }
-
-    protected final void blockingReloadDictionaryIfRequired() {
-        reloadDictionaryIfRequired();
-        waitForDictionaryLoading();
-    }
-
     // Local to reverseLookUp, but do not allocate each time.
     private final char[] mLookedUpString = new char[BinaryDictionary.MAX_WORD_LENGTH];
 
@@ -641,7 +625,7 @@
      * @param terminalNodes list of terminal nodes we want to add
      * @param suggestions the suggestion collection to add the word to
      */
-    private void reverseLookUp(LinkedList<NextWord> terminalNodes,
+    private void reverseLookUp(final LinkedList<NextWord> terminalNodes,
             final ArrayList<SuggestedWordInfo> suggestions) {
         Node node;
         int freq;
@@ -714,7 +698,7 @@
         }
     }
 
-    private static char toLowerCase(char c) {
+    private static char toLowerCase(final char c) {
         char baseChar = c;
         if (c < BASE_CHARS.length) {
             baseChar = BASE_CHARS[c];
diff --git a/java/src/com/android/inputmethod/latin/InputPointers.java b/java/src/com/android/inputmethod/latin/InputPointers.java
index 6b48aab..7dffd96 100644
--- a/java/src/com/android/inputmethod/latin/InputPointers.java
+++ b/java/src/com/android/inputmethod/latin/InputPointers.java
@@ -16,6 +16,8 @@
 
 package com.android.inputmethod.latin;
 
+import com.android.inputmethod.annotations.UsedForTesting;
+
 // TODO: This class is not thread-safe.
 public final class InputPointers {
     private final int mDefaultCapacity;
@@ -39,7 +41,8 @@
         mTimes.add(index, time);
     }
 
-    public void addPointer(int x, int y, int pointerId, int time) {
+    @UsedForTesting
+    void addPointer(int x, int y, int pointerId, int time) {
         mXCoordinates.add(x);
         mYCoordinates.add(y);
         mPointerIds.add(pointerId);
@@ -66,7 +69,8 @@
      * @param startPos the starting index of the pointers in {@code src}.
      * @param length the number of pointers to be appended.
      */
-    public void append(InputPointers src, int startPos, int length) {
+    @UsedForTesting
+    void append(InputPointers src, int startPos, int length) {
         if (length == 0) {
             return;
         }
diff --git a/java/src/com/android/inputmethod/latin/LastComposedWord.java b/java/src/com/android/inputmethod/latin/LastComposedWord.java
index 94cdc9b..44ef012 100644
--- a/java/src/com/android/inputmethod/latin/LastComposedWord.java
+++ b/java/src/com/android/inputmethod/latin/LastComposedWord.java
@@ -44,7 +44,7 @@
     public final String mTypedWord;
     public final String mCommittedWord;
     public final String mSeparatorString;
-    public final CharSequence mPrevWord;
+    public final String mPrevWord;
     public final InputPointers mInputPointers = new InputPointers(BinaryDictionary.MAX_WORD_LENGTH);
 
     private boolean mActive;
@@ -56,7 +56,7 @@
     // immutable. Do not fiddle with their contents after you passed them to this constructor.
     public LastComposedWord(final int[] primaryKeyCodes, final InputPointers inputPointers,
             final String typedWord, final String committedWord,
-            final String separatorString, final CharSequence prevWord) {
+            final String separatorString, final String prevWord) {
         mPrimaryKeyCodes = primaryKeyCodes;
         if (inputPointers != null) {
             mInputPointers.copy(inputPointers);
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 4cf6a51..5cc9f51 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -60,6 +60,7 @@
 
 import com.android.inputmethod.accessibility.AccessibilityUtils;
 import com.android.inputmethod.accessibility.AccessibleKeyboardViewProxy;
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.compat.CompatUtils;
 import com.android.inputmethod.compat.InputMethodManagerCompatWrapper;
 import com.android.inputmethod.compat.InputMethodServiceCompatUtils;
@@ -132,14 +133,14 @@
     private View mKeyPreviewBackingView;
     private View mSuggestionsContainer;
     private SuggestionStripView mSuggestionStripView;
-    /* package for tests */ Suggest mSuggest;
+    @UsedForTesting Suggest mSuggest;
     private CompletionInfo[] mApplicationSpecifiedCompletions;
     private ApplicationInfo mTargetApplicationInfo;
 
     private InputMethodManagerCompatWrapper mImm;
     private Resources mResources;
     private SharedPreferences mPrefs;
-    /* package for tests */ final KeyboardSwitcher mKeyboardSwitcher;
+    @UsedForTesting final KeyboardSwitcher mKeyboardSwitcher;
     private final SubtypeSwitcher mSubtypeSwitcher;
     private boolean mShouldSwitchToLastSubtype = true;
 
@@ -171,7 +172,7 @@
             new DictionaryPackInstallBroadcastReceiver(this);
 
     // Keeps track of most recently inserted text (multi-character key) for reverting
-    private CharSequence mEnteredText;
+    private String mEnteredText;
 
     private boolean mIsAutoCorrectionIndicatorOn;
 
@@ -422,7 +423,7 @@
     }
 
     // Has to be package-visible for unit tests
-    /* package for test */
+    @UsedForTesting
     void loadSettings() {
         // Note that the calling sequence of onCreate() and onCurrentInputMethodSubtypeChanged()
         // is not guaranteed. It may even be called at the same time on a different thread.
@@ -1093,7 +1094,7 @@
 
     private void commitTyped(final String separatorString) {
         if (!mWordComposer.isComposingWord()) return;
-        final CharSequence typedWord = mWordComposer.getTypedWord();
+        final String typedWord = mWordComposer.getTypedWord();
         if (typedWord.length() > 0) {
             commitChosenWord(typedWord, LastComposedWord.COMMIT_TYPE_USER_TYPED_WORD,
                     separatorString);
@@ -1379,7 +1380,7 @@
 
     // Called from PointerTracker through the KeyboardActionListener interface
     @Override
-    public void onTextInput(final CharSequence rawText) {
+    public void onTextInput(final String rawText) {
         mConnection.beginBatchEdit();
         if (mWordComposer.isComposingWord()) {
             commitCurrentAutoCorrection(rawText.toString());
@@ -1387,7 +1388,7 @@
             resetComposingState(true /* alsoResetLastComposedWord */);
         }
         mHandler.postUpdateSuggestionStrip();
-        final CharSequence text = specificTldProcessingOnTextInput(rawText);
+        final String text = specificTldProcessingOnTextInput(rawText);
         if (SPACE_STATE_PHANTOM == mSpaceState) {
             sendKeyCodePoint(Keyboard.CODE_SPACE);
         }
@@ -1558,7 +1559,7 @@
         mKeyboardSwitcher.updateShiftState();
     }
 
-    private CharSequence specificTldProcessingOnTextInput(final CharSequence text) {
+    private String specificTldProcessingOnTextInput(final String text) {
         if (text.length() <= 1 || text.charAt(0) != Keyboard.CODE_PERIOD
                 || !Character.isLetter(text.charAt(1))) {
             // Not a tld: do nothing.
@@ -1571,7 +1572,7 @@
         final CharSequence lastOne = mConnection.getTextBeforeCursor(1, 0);
         if (lastOne != null && lastOne.length() == 1
                 && lastOne.charAt(0) == Keyboard.CODE_PERIOD) {
-            return text.subSequence(1, text.length());
+            return text.substring(1);
         } else {
             return text;
         }
@@ -1831,7 +1832,7 @@
         return didAutoCorrect;
     }
 
-    private CharSequence getTextWithUnderline(final CharSequence text) {
+    private CharSequence getTextWithUnderline(final String text) {
         return mIsAutoCorrectionIndicatorOn
                 ? SuggestionSpanUtils.getTextWithAutoCorrectionIndicatorUnderline(this, text)
                 : text;
@@ -1848,7 +1849,7 @@
 
     // TODO: make this private
     // Outside LatinIME, only used by the test suite.
-    /* package for tests */
+    @UsedForTesting
     boolean isShowingPunctuationList() {
         if (mSuggestionStripView == null) return false;
         return mCurrentSettings.mSuggestPuncList == mSuggestionStripView.getSuggestions();
@@ -1926,7 +1927,7 @@
         // whatever is *before* the half-committed word in the buffer, hence 2; if we aren't, we
         // should just skip whitespace if any, so 1.
         // TODO: this is slow (2-way IPC) - we should probably cache this instead.
-        final CharSequence prevWord =
+        final String prevWord =
                 mConnection.getNthPreviousWord(mCurrentSettings.mWordSeparators,
                 mWordComposer.isComposingWord() ? 2 : 1);
         final SuggestedWords suggestedWords = mSuggest.getSuggestedWords(mWordComposer,
@@ -1935,7 +1936,7 @@
         return maybeRetrieveOlderSuggestions(typedWord, suggestedWords);
     }
 
-    private SuggestedWords maybeRetrieveOlderSuggestions(final CharSequence typedWord,
+    private SuggestedWords maybeRetrieveOlderSuggestions(final String typedWord,
             final SuggestedWords suggestedWords) {
         // TODO: consolidate this into getSuggestedWords
         // We update the suggestion strip only when we have some suggestions to show, i.e. when
@@ -1965,13 +1966,12 @@
         }
     }
 
-    private void showSuggestionStrip(final SuggestedWords suggestedWords,
-            final CharSequence typedWord) {
+    private void showSuggestionStrip(final SuggestedWords suggestedWords, final String typedWord) {
         if (suggestedWords.isEmpty()) {
             clearSuggestionStrip();
             return;
         }
-        final CharSequence autoCorrection;
+        final String autoCorrection;
         if (suggestedWords.mWillAutoCorrect) {
             autoCorrection = suggestedWords.getWord(1);
         } else {
@@ -1989,9 +1989,9 @@
         if (mHandler.hasPendingUpdateSuggestions()) {
             updateSuggestionStrip();
         }
-        final CharSequence typedAutoCorrection = mWordComposer.getAutoCorrectionOrNull();
+        final String typedAutoCorrection = mWordComposer.getAutoCorrectionOrNull();
         final String typedWord = mWordComposer.getTypedWord();
-        final CharSequence autoCorrection = (typedAutoCorrection != null)
+        final String autoCorrection = (typedAutoCorrection != null)
                 ? typedAutoCorrection : typedWord;
         if (autoCorrection != null) {
             if (TextUtils.isEmpty(typedWord)) {
@@ -2022,7 +2022,7 @@
     // Called from {@link SuggestionStripView} through the {@link SuggestionStripView#Listener}
     // interface
     @Override
-    public void pickSuggestionManually(final int index, final CharSequence suggestion) {
+    public void pickSuggestionManually(final int index, final String suggestion) {
         final SuggestedWords suggestedWords = mSuggestionStripView.getSuggestions();
         // If this is a punctuation picked from the suggestion strip, pass it to onCodeInput
         if (suggestion.length() == 1 && isShowingPunctuationList()) {
@@ -2107,13 +2107,13 @@
     /**
      * Commits the chosen word to the text field and saves it for later retrieval.
      */
-    private void commitChosenWord(final CharSequence chosenWord, final int commitType,
+    private void commitChosenWord(final String chosenWord, final int commitType,
             final String separatorString) {
         final SuggestedWords suggestedWords = mSuggestionStripView.getSuggestions();
         mConnection.commitText(SuggestionSpanUtils.getTextWithSuggestionSpan(
                 this, chosenWord, suggestedWords, mIsMainDictionaryAvailable), 1);
         // Add the word to the user history dictionary
-        final CharSequence prevWord = addToUserHistoryDictionary(chosenWord);
+        final String prevWord = addToUserHistoryDictionary(chosenWord);
         // TODO: figure out here if this is an auto-correct or if the best word is actually
         // what user typed. Note: currently this is done much later in
         // LastComposedWord#didCommitTypedWord by string equality of the remembered
@@ -2132,7 +2132,7 @@
         setSuggestionStripShown(isSuggestionsStripVisible());
     }
 
-    private CharSequence addToUserHistoryDictionary(final CharSequence suggestion) {
+    private String addToUserHistoryDictionary(final String suggestion) {
         if (TextUtils.isEmpty(suggestion)) return null;
         if (mSuggest == null) return null;
 
@@ -2147,19 +2147,18 @@
                     = mConnection.getNthPreviousWord(mCurrentSettings.mWordSeparators, 2);
             final String secondWord;
             if (mWordComposer.wasAutoCapitalized() && !mWordComposer.isMostlyCaps()) {
-                secondWord = suggestion.toString().toLowerCase(
-                        mSubtypeSwitcher.getCurrentSubtypeLocale());
+                secondWord = suggestion.toLowerCase(mSubtypeSwitcher.getCurrentSubtypeLocale());
             } else {
-                secondWord = suggestion.toString();
+                secondWord = suggestion;
             }
             // We demote unrecognized words (frequency < 0, below) by specifying them as "invalid".
             // We don't add words with 0-frequency (assuming they would be profanity etc.).
             final int maxFreq = AutoCorrection.getMaxFrequency(
                     mSuggest.getUnigramDictionaries(), suggestion);
             if (maxFreq == 0) return null;
-            userHistoryDictionary.addToUserHistory(null == prevWord ? null : prevWord.toString(),
-                    secondWord, maxFreq > 0);
-            return prevWord;
+            final String prevWordString = (null == prevWord) ? null : prevWord.toString();
+            userHistoryDictionary.addToUserHistory(prevWordString, secondWord, maxFreq > 0);
+            return prevWordString;
         }
         return null;
     }
@@ -2184,9 +2183,9 @@
     }
 
     private void revertCommit() {
-        final CharSequence previousWord = mLastComposedWord.mPrevWord;
+        final String previousWord = mLastComposedWord.mPrevWord;
         final String originallyTypedWord = mLastComposedWord.mTypedWord;
-        final CharSequence committedWord = mLastComposedWord.mCommittedWord;
+        final String committedWord = mLastComposedWord.mCommittedWord;
         final int cancelLength = committedWord.length();
         final int separatorLength = LastComposedWord.getSeparatorLength(
                 mLastComposedWord.mSeparatorString);
@@ -2196,9 +2195,9 @@
             if (mWordComposer.isComposingWord()) {
                 throw new RuntimeException("revertCommit, but we are composing a word");
             }
-            final String wordBeforeCursor =
+            final CharSequence wordBeforeCursor =
                     mConnection.getTextBeforeCursor(deleteLength, 0)
-                            .subSequence(0, cancelLength).toString();
+                            .subSequence(0, cancelLength);
             if (!TextUtils.equals(committedWord, wordBeforeCursor)) {
                 throw new RuntimeException("revertCommit check failed: we thought we were "
                         + "reverting \"" + committedWord
@@ -2232,7 +2231,7 @@
 
     // TODO: Make this private
     // Outside LatinIME, only used by the {@link InputTestsBase} test suite.
-    /* package for test */
+    @UsedForTesting
     void loadKeyboard() {
         // When the device locale is changed in SetupWizard etc., this method may get called via
         // onConfigurationChanged before SoftInputWindow is shown.
diff --git a/java/src/com/android/inputmethod/latin/RichInputConnection.java b/java/src/com/android/inputmethod/latin/RichInputConnection.java
index 2144136..bf2dfbc 100644
--- a/java/src/com/android/inputmethod/latin/RichInputConnection.java
+++ b/java/src/com/android/inputmethod/latin/RichInputConnection.java
@@ -398,7 +398,7 @@
         if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
     }
 
-    public CharSequence getNthPreviousWord(final String sentenceSeperators, final int n) {
+    public String getNthPreviousWord(final String sentenceSeperators, final int n) {
         mIC = mParent.getCurrentInputConnection();
         if (null == mIC) return null;
         final CharSequence prev = mIC.getTextBeforeCursor(LOOKBACK_CHARACTER_NUM, 0);
@@ -466,19 +466,22 @@
     // (n = 2) "abc|" -> null
     // (n = 2) "abc |" -> null
     // (n = 2) "abc. def|" -> null
-    public static CharSequence getNthPreviousWord(final CharSequence prev,
+    public static String getNthPreviousWord(final CharSequence prev,
             final String sentenceSeperators, final int n) {
         if (prev == null) return null;
-        String[] w = spaceRegex.split(prev);
+        final String[] w = spaceRegex.split(prev);
 
         // If we can't find n words, or we found an empty word, return null.
-        if (w.length < n || w[w.length - n].length() <= 0) return null;
+        if (w.length < n) return null;
+        final String nthPrevWord = w[w.length - n];
+        final int length = nthPrevWord.length();
+        if (length <= 0) return null;
 
         // If ends in a separator, return null
-        char lastChar = w[w.length - n].charAt(w[w.length - n].length() - 1);
+        final char lastChar = nthPrevWord.charAt(length - 1);
         if (sentenceSeperators.contains(String.valueOf(lastChar))) return null;
 
-        return w[w.length - n];
+        return nthPrevWord;
     }
 
     /**
@@ -511,19 +514,20 @@
      *   be included in the returned range
      * @return a range containing the text surrounding the cursor
      */
-    public Range getWordRangeAtCursor(String sep, int additionalPrecedingWordsCount) {
+    public Range getWordRangeAtCursor(final String sep, final int additionalPrecedingWordsCount) {
         mIC = mParent.getCurrentInputConnection();
         if (mIC == null || sep == null) {
             return null;
         }
-        CharSequence before = mIC.getTextBeforeCursor(1000, 0);
-        CharSequence after = mIC.getTextAfterCursor(1000, 0);
+        final CharSequence before = mIC.getTextBeforeCursor(1000, 0);
+        final CharSequence after = mIC.getTextAfterCursor(1000, 0);
         if (before == null || after == null) {
             return null;
         }
 
         // Going backward, alternate skipping non-separators and separators until enough words
         // have been read.
+        int count = additionalPrecedingWordsCount;
         int start = before.length();
         boolean isStoppingAtWhitespace = true;  // toggles to indicate what to stop at
         while (true) { // see comments below for why this is guaranteed to halt
@@ -540,7 +544,7 @@
             // isStoppingAtWhitespace is true every other time through the loop,
             // so additionalPrecedingWordsCount is guaranteed to become < 0, which
             // guarantees outer loop termination
-            if (isStoppingAtWhitespace && (--additionalPrecedingWordsCount < 0)) {
+            if (isStoppingAtWhitespace && (--count < 0)) {
                 break;  // outer loop
             }
             isStoppingAtWhitespace = !isStoppingAtWhitespace;
@@ -558,7 +562,7 @@
             }
         }
 
-        int cursor = getCursorPosition();
+        final int cursor = getCursorPosition();
         if (start >= 0 && cursor + end <= after.length() + before.length()) {
             String word = before.toString().substring(start, before.length())
                     + after.toString().substring(0, end);
@@ -569,8 +573,8 @@
     }
 
     public boolean isCursorTouchingWord(final SettingsValues settingsValues) {
-        CharSequence before = getTextBeforeCursor(1, 0);
-        CharSequence after = getTextAfterCursor(1, 0);
+        final CharSequence before = getTextBeforeCursor(1, 0);
+        final CharSequence after = getTextAfterCursor(1, 0);
         if (!TextUtils.isEmpty(before) && !settingsValues.isWordSeparator(before.charAt(0))
                 && !settingsValues.isSymbolExcludedFromWordSeparators(before.charAt(0))) {
             return true;
diff --git a/java/src/com/android/inputmethod/latin/StringUtils.java b/java/src/com/android/inputmethod/latin/StringUtils.java
index df77098..44b75b5 100644
--- a/java/src/com/android/inputmethod/latin/StringUtils.java
+++ b/java/src/com/android/inputmethod/latin/StringUtils.java
@@ -16,9 +16,11 @@
 
 package com.android.inputmethod.latin;
 
+import android.text.InputType;
 import android.text.TextUtils;
 
-import com.android.inputmethod.keyboard.Keyboard; // For character constants
+//For character constants
+import com.android.inputmethod.keyboard.Keyboard;
 
 import java.util.ArrayList;
 import java.util.Locale;
@@ -28,30 +30,30 @@
         // This utility class is not publicly instantiable.
     }
 
-    public static int codePointCount(String text) {
+    public static int codePointCount(final String text) {
         if (TextUtils.isEmpty(text)) return 0;
         return text.codePointCount(0, text.length());
     }
 
-    public static boolean containsInArray(String key, String[] array) {
+    public static boolean containsInArray(final String key, final String[] array) {
         for (final String element : array) {
             if (key.equals(element)) return true;
         }
         return false;
     }
 
-    public static boolean containsInCsv(String key, String csv) {
+    public static boolean containsInCsv(final String key, final String csv) {
         if (TextUtils.isEmpty(csv)) return false;
         return containsInArray(key, csv.split(","));
     }
 
-    public static String appendToCsvIfNotExists(String key, String csv) {
+    public static String appendToCsvIfNotExists(final String key, final String csv) {
         if (TextUtils.isEmpty(csv)) return key;
         if (containsInCsv(key, csv)) return csv;
         return csv + "," + key;
     }
 
-    public static String removeFromCsvIfExists(String key, String csv) {
+    public static String removeFromCsvIfExists(final String key, final String csv) {
         if (TextUtils.isEmpty(csv)) return "";
         final String[] elements = csv.split(",");
         if (!containsInArray(key, elements)) return csv;
@@ -63,82 +65,20 @@
     }
 
     /**
-     * Returns true if a and b are equal ignoring the case of the character.
-     * @param a first character to check
-     * @param b second character to check
-     * @return {@code true} if a and b are equal, {@code false} otherwise.
-     */
-    public static boolean equalsIgnoreCase(char a, char b) {
-        // Some language, such as Turkish, need testing both cases.
-        return a == b
-                || Character.toLowerCase(a) == Character.toLowerCase(b)
-                || Character.toUpperCase(a) == Character.toUpperCase(b);
-    }
-
-    /**
-     * Returns true if a and b are equal ignoring the case of the characters, including if they are
-     * both null.
-     * @param a first CharSequence to check
-     * @param b second CharSequence to check
-     * @return {@code true} if a and b are equal, {@code false} otherwise.
-     */
-    public static boolean equalsIgnoreCase(CharSequence a, CharSequence b) {
-        if (a == b)
-            return true;  // including both a and b are null.
-        if (a == null || b == null)
-            return false;
-        final int length = a.length();
-        if (length != b.length())
-            return false;
-        for (int i = 0; i < length; i++) {
-            if (!equalsIgnoreCase(a.charAt(i), b.charAt(i)))
-                return false;
-        }
-        return true;
-    }
-
-    /**
-     * Returns true if a and b are equal ignoring the case of the characters, including if a is null
-     * and b is zero length.
-     * @param a CharSequence to check
-     * @param b character array to check
-     * @param offset start offset of array b
-     * @param length length of characters in array b
-     * @return {@code true} if a and b are equal, {@code false} otherwise.
-     * @throws IndexOutOfBoundsException
-     *   if {@code offset < 0 || length < 0 || offset + length > data.length}.
-     * @throws NullPointerException if {@code b == null}.
-     */
-    public static boolean equalsIgnoreCase(CharSequence a, char[] b, int offset, int length) {
-        if (offset < 0 || length < 0 || length > b.length - offset)
-            throw new IndexOutOfBoundsException("array.length=" + b.length + " offset=" + offset
-                    + " length=" + length);
-        if (a == null)
-            return length == 0;  // including a is null and b is zero length.
-        if (a.length() != length)
-            return false;
-        for (int i = 0; i < length; i++) {
-            if (!equalsIgnoreCase(a.charAt(i), b[offset + i]))
-                return false;
-        }
-        return true;
-    }
-
-    /**
      * Remove duplicates from an array of strings.
      *
      * This method will always keep the first occurrence of all strings at their position
      * in the array, removing the subsequent ones.
      */
-    public static void removeDupes(final ArrayList<CharSequence> suggestions) {
+    public static void removeDupes(final ArrayList<String> suggestions) {
         if (suggestions.size() < 2) return;
         int i = 1;
         // Don't cache suggestions.size(), since we may be removing items
         while (i < suggestions.size()) {
-            final CharSequence cur = suggestions.get(i);
+            final String cur = suggestions.get(i);
             // Compare each suggestion with each previous suggestion
             for (int j = 0; j < i; j++) {
-                CharSequence previous = suggestions.get(j);
+                final String previous = suggestions.get(j);
                 if (TextUtils.equals(cur, previous)) {
                     suggestions.remove(i);
                     i--;
@@ -149,7 +89,7 @@
         }
     }
 
-    public static String toTitleCase(String s, Locale locale) {
+    public static String toTitleCase(final String s, final Locale locale) {
         if (s.length() <= 1) {
             // TODO: is this really correct? Shouldn't this be s.toUpperCase()?
             return s;
@@ -165,21 +105,19 @@
         return s.toUpperCase(locale).charAt(0) + s.substring(1);
     }
 
+    private static final int[] EMPTY_CODEPOINTS = {};
+
     public static int[] toCodePointArray(final String string) {
-        final char[] characters = string.toCharArray();
-        final int length = characters.length;
-        final int[] codePoints = new int[Character.codePointCount(characters, 0, length)];
+        final int length = string.length();
         if (length <= 0) {
-            return new int[0];
+            return EMPTY_CODEPOINTS;
         }
-        int codePoint = Character.codePointAt(characters, 0);
-        int dsti = 0;
-        for (int srci = Character.charCount(codePoint);
-                srci < length; srci += Character.charCount(codePoint), ++dsti) {
-            codePoints[dsti] = codePoint;
-            codePoint = Character.codePointAt(characters, srci);
+        final int[] codePoints = new int[string.codePointCount(0, length)];
+        int destIndex = 0;
+        for (int index = 0; index < length; index = string.offsetByCodePoints(index, 1)) {
+            codePoints[destIndex] = string.codePointAt(index);
+            destIndex++;
         }
-        codePoints[dsti] = codePoint;
         return codePoints;
     }
 
diff --git a/java/src/com/android/inputmethod/latin/Suggest.java b/java/src/com/android/inputmethod/latin/Suggest.java
index f0e3b4e..c87161b 100644
--- a/java/src/com/android/inputmethod/latin/Suggest.java
+++ b/java/src/com/android/inputmethod/latin/Suggest.java
@@ -19,6 +19,7 @@
 import android.content.Context;
 import android.text.TextUtils;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.Keyboard;
 import com.android.inputmethod.keyboard.ProximityInfo;
 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
@@ -38,7 +39,7 @@
     public static final String TAG = Suggest.class.getSimpleName();
 
     // Session id for
-    // {@link #getSuggestedWords(WordComposer,CharSequence,ProximityInfo,boolean,int)}.
+    // {@link #getSuggestedWords(WordComposer,String,ProximityInfo,boolean,int)}.
     public static final int SESSION_TYPING = 0;
     public static final int SESSION_GESTURE = 1;
 
@@ -71,7 +72,8 @@
         mLocale = locale;
     }
 
-    /* package for test */ Suggest(final Context context, final File dictionary,
+    @UsedForTesting
+    Suggest(final Context context, final File dictionary,
             final long startOffset, final long length, final Locale locale) {
         final Dictionary mainDict = DictionaryFactory.createDictionaryForTest(context, dictionary,
                 startOffset, length /* useFullEditDistance */, false, locale);
@@ -138,7 +140,7 @@
      * Sets an optional user dictionary resource to be loaded. The user dictionary is consulted
      * before the main dictionary, if set. This refers to the system-managed user dictionary.
      */
-    public void setUserDictionary(UserBinaryDictionary userDictionary) {
+    public void setUserDictionary(final UserBinaryDictionary userDictionary) {
         addOrReplaceDictionary(mDictionaries, Dictionary.TYPE_USER, userDictionary);
     }
 
@@ -147,12 +149,12 @@
      * the contacts dictionary by passing null to this method. In this case no contacts dictionary
      * won't be used.
      */
-    public void setContactsDictionary(ContactsBinaryDictionary contactsDictionary) {
+    public void setContactsDictionary(final ContactsBinaryDictionary contactsDictionary) {
         mContactsDict = contactsDictionary;
         addOrReplaceDictionary(mDictionaries, Dictionary.TYPE_CONTACTS, contactsDictionary);
     }
 
-    public void setUserHistoryDictionary(UserHistoryDictionary userHistoryDictionary) {
+    public void setUserHistoryDictionary(final UserHistoryDictionary userHistoryDictionary) {
         addOrReplaceDictionary(mDictionaries, Dictionary.TYPE_USER_HISTORY, userHistoryDictionary);
     }
 
@@ -160,9 +162,9 @@
         mAutoCorrectionThreshold = threshold;
     }
 
-    public SuggestedWords getSuggestedWords(
-            final WordComposer wordComposer, CharSequence prevWordForBigram,
-            final ProximityInfo proximityInfo, final boolean isCorrectionEnabled, int sessionId) {
+    public SuggestedWords getSuggestedWords(final WordComposer wordComposer,
+            final String prevWordForBigram, final ProximityInfo proximityInfo,
+            final boolean isCorrectionEnabled, final int sessionId) {
         LatinImeLogger.onStartSuggestion(prevWordForBigram);
         if (wordComposer.isBatchMode()) {
             return getSuggestedWordsForBatchInput(
@@ -174,9 +176,9 @@
     }
 
     // Retrieves suggestions for the typing input.
-    private SuggestedWords getSuggestedWordsForTypingInput(
-            final WordComposer wordComposer, CharSequence prevWordForBigram,
-            final ProximityInfo proximityInfo, final boolean isCorrectionEnabled) {
+    private SuggestedWords getSuggestedWordsForTypingInput(final WordComposer wordComposer,
+            final String prevWordForBigram, final ProximityInfo proximityInfo,
+            final boolean isCorrectionEnabled) {
         final int trailingSingleQuotesCount = wordComposer.trailingSingleQuotesCount();
         final BoundedTreeSet suggestionsSet = new BoundedTreeSet(sSuggestedWordInfoComparator,
                 MAX_SUGGESTIONS);
@@ -203,7 +205,7 @@
                     wordComposerForLookup, prevWordForBigram, proximityInfo));
         }
 
-        final CharSequence whitelistedWord;
+        final String whitelistedWord;
         if (suggestionsSet.isEmpty()) {
             whitelistedWord = null;
         } else if (SuggestedWordInfo.KIND_WHITELIST != suggestionsSet.first().mKind) {
@@ -287,9 +289,9 @@
     }
 
     // Retrieves suggestions for the batch input.
-    private SuggestedWords getSuggestedWordsForBatchInput(
-            final WordComposer wordComposer, CharSequence prevWordForBigram,
-            final ProximityInfo proximityInfo, int sessionId) {
+    private SuggestedWords getSuggestedWordsForBatchInput(final WordComposer wordComposer,
+            final String prevWordForBigram, final ProximityInfo proximityInfo,
+            final int sessionId) {
         final BoundedTreeSet suggestionsSet = new BoundedTreeSet(sSuggestedWordInfoComparator,
                 MAX_SUGGESTIONS);
 
@@ -307,7 +309,7 @@
         }
 
         for (SuggestedWordInfo wordInfo : suggestionsSet) {
-            LatinImeLogger.onAddSuggestedWord(wordInfo.mWord.toString(), wordInfo.mSourceDict);
+            LatinImeLogger.onAddSuggestedWord(wordInfo.mWord, wordInfo.mSourceDict);
         }
 
         final ArrayList<SuggestedWordInfo> suggestionsContainer =
@@ -372,7 +374,7 @@
             if (o1.mScore < o2.mScore) return 1;
             if (o1.mCodePointCount < o2.mCodePointCount) return -1;
             if (o1.mCodePointCount > o2.mCodePointCount) return 1;
-            return o1.mWord.toString().compareTo(o2.mWord.toString());
+            return o1.mWord.compareTo(o2.mWord);
         }
     }
     private static final SuggestedWordInfoComparator sSuggestedWordInfoComparator =
@@ -383,16 +385,17 @@
             final boolean isFirstCharCapitalized, final int trailingSingleQuotesCount) {
         final StringBuilder sb = new StringBuilder(wordInfo.mWord.length());
         if (isAllUpperCase) {
-            sb.append(wordInfo.mWord.toString().toUpperCase(locale));
+            sb.append(wordInfo.mWord.toUpperCase(locale));
         } else if (isFirstCharCapitalized) {
-            sb.append(StringUtils.toTitleCase(wordInfo.mWord.toString(), locale));
+            sb.append(StringUtils.toTitleCase(wordInfo.mWord, locale));
         } else {
             sb.append(wordInfo.mWord);
         }
         for (int i = trailingSingleQuotesCount - 1; i >= 0; --i) {
             sb.appendCodePoint(Keyboard.CODE_SINGLE_QUOTE);
         }
-        return new SuggestedWordInfo(sb, wordInfo.mScore, wordInfo.mKind, wordInfo.mSourceDict);
+        return new SuggestedWordInfo(sb.toString(), wordInfo.mScore, wordInfo.mKind,
+                wordInfo.mSourceDict);
     }
 
     public void close() {
diff --git a/java/src/com/android/inputmethod/latin/SuggestedWords.java b/java/src/com/android/inputmethod/latin/SuggestedWords.java
index ad94aff..572f290 100644
--- a/java/src/com/android/inputmethod/latin/SuggestedWords.java
+++ b/java/src/com/android/inputmethod/latin/SuggestedWords.java
@@ -90,11 +90,14 @@
     public static ArrayList<SuggestedWordInfo> getFromApplicationSpecifiedCompletions(
             final CompletionInfo[] infos) {
         final ArrayList<SuggestedWordInfo> result = CollectionUtils.newArrayList();
-        for (CompletionInfo info : infos) {
-            if (null != info && info.getText() != null) {
-                result.add(new SuggestedWordInfo(info.getText(), SuggestedWordInfo.MAX_SCORE,
-                        SuggestedWordInfo.KIND_APP_DEFINED, Dictionary.TYPE_APPLICATION_DEFINED));
-            }
+        for (final CompletionInfo info : infos) {
+            if (info == null) continue;
+            final CharSequence text = info.getText();
+            if (null == text) continue;
+            final SuggestedWordInfo suggestedWordInfo = new SuggestedWordInfo(text.toString(),
+                    SuggestedWordInfo.MAX_SCORE, SuggestedWordInfo.KIND_APP_DEFINED,
+                    Dictionary.TYPE_APPLICATION_DEFINED);
+            result.add(suggestedWordInfo);
         }
         return result;
     }
@@ -102,7 +105,7 @@
     // Should get rid of the first one (what the user typed previously) from suggestions
     // and replace it with what the user currently typed.
     public static ArrayList<SuggestedWordInfo> getTypedWordAndPreviousSuggestions(
-            final CharSequence typedWord, final SuggestedWords previousSuggestions) {
+            final String typedWord, final SuggestedWords previousSuggestions) {
         final ArrayList<SuggestedWordInfo> suggestionsList = CollectionUtils.newArrayList();
         final HashSet<String> alreadySeen = CollectionUtils.newHashSet();
         suggestionsList.add(new SuggestedWordInfo(typedWord, SuggestedWordInfo.MAX_SCORE,
@@ -111,7 +114,7 @@
         final int previousSize = previousSuggestions.size();
         for (int pos = 1; pos < previousSize; pos++) {
             final SuggestedWordInfo prevWordInfo = previousSuggestions.getWordInfo(pos);
-            final String prevWord = prevWordInfo.mWord.toString();
+            final String prevWord = prevWordInfo.mWord;
             // Filter out duplicate suggestion.
             if (!alreadySeen.contains(prevWord)) {
                 suggestionsList.add(prevWordInfo);
@@ -139,9 +142,9 @@
         public final String mSourceDict;
         private String mDebugString = "";
 
-        public SuggestedWordInfo(final CharSequence word, final int score, final int kind,
+        public SuggestedWordInfo(final String word, final int score, final int kind,
                 final String sourceDict) {
-            mWord = word.toString();
+            mWord = word;
             mScore = score;
             mKind = kind;
             mSourceDict = sourceDict;
@@ -149,7 +152,7 @@
         }
 
 
-        public void setDebugString(String str) {
+        public void setDebugString(final String str) {
             if (null == str) throw new NullPointerException("Debug info is null");
             mDebugString = str;
         }
@@ -171,7 +174,7 @@
             if (TextUtils.isEmpty(mDebugString)) {
                 return mWord;
             } else {
-                return mWord + " (" + mDebugString.toString() + ")";
+                return mWord + " (" + mDebugString + ")";
             }
         }
 
diff --git a/java/src/com/android/inputmethod/latin/SynchronouslyLoadedContactsBinaryDictionary.java b/java/src/com/android/inputmethod/latin/SynchronouslyLoadedContactsBinaryDictionary.java
index 8f21b7b..ec4dc14 100644
--- a/java/src/com/android/inputmethod/latin/SynchronouslyLoadedContactsBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/SynchronouslyLoadedContactsBinaryDictionary.java
@@ -33,13 +33,13 @@
 
     @Override
     public synchronized ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer codes,
-            final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo) {
+            final String prevWordForBigrams, final ProximityInfo proximityInfo) {
         syncReloadDictionaryIfRequired();
         return super.getSuggestions(codes, prevWordForBigrams, proximityInfo);
     }
 
     @Override
-    public synchronized boolean isValidWord(CharSequence word) {
+    public synchronized boolean isValidWord(final String word) {
         syncReloadDictionaryIfRequired();
         return isValidWordInner(word);
     }
diff --git a/java/src/com/android/inputmethod/latin/SynchronouslyLoadedUserBinaryDictionary.java b/java/src/com/android/inputmethod/latin/SynchronouslyLoadedUserBinaryDictionary.java
index 612f54d..4bdaf20 100644
--- a/java/src/com/android/inputmethod/latin/SynchronouslyLoadedUserBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/SynchronouslyLoadedUserBinaryDictionary.java
@@ -36,13 +36,13 @@
 
     @Override
     public synchronized ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer codes,
-            final CharSequence prevWordForBigrams, final ProximityInfo proximityInfo) {
+            final String prevWordForBigrams, final ProximityInfo proximityInfo) {
         syncReloadDictionaryIfRequired();
         return super.getSuggestions(codes, prevWordForBigrams, proximityInfo);
     }
 
     @Override
-    public synchronized boolean isValidWord(CharSequence word) {
+    public synchronized boolean isValidWord(final String word) {
         syncReloadDictionaryIfRequired();
         return isValidWordInner(word);
     }
diff --git a/java/src/com/android/inputmethod/latin/UserBinaryDictionary.java b/java/src/com/android/inputmethod/latin/UserBinaryDictionary.java
index 60e6fa1..00c3cbe 100644
--- a/java/src/com/android/inputmethod/latin/UserBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/UserBinaryDictionary.java
@@ -200,7 +200,7 @@
         mContext.startActivity(intent);
     }
 
-    private void addWords(Cursor cursor) {
+    private void addWords(final Cursor cursor) {
         // 16 is JellyBean, but we want this to compile against ICS.
         final boolean hasShortcutColumn = android.os.Build.VERSION.SDK_INT >= 16;
         clearFusionDictionary();
diff --git a/java/src/com/android/inputmethod/latin/UserHistoryDictIOUtils.java b/java/src/com/android/inputmethod/latin/UserHistoryDictIOUtils.java
index e390111..7871977 100644
--- a/java/src/com/android/inputmethod/latin/UserHistoryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/UserHistoryDictIOUtils.java
@@ -18,6 +18,7 @@
 
 import android.util.Log;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictIOUtils;
 import com.android.inputmethod.latin.makedict.BinaryDictInputOutput;
 import com.android.inputmethod.latin.makedict.BinaryDictInputOutput.FusionDictionaryBufferInterface;
@@ -129,7 +130,8 @@
     /**
      * Constructs a new FusionDictionary from BigramDictionaryInterface.
      */
-    /* packages for test */ static FusionDictionary constructFusionDictionary(
+    @UsedForTesting
+    static FusionDictionary constructFusionDictionary(
             final BigramDictionaryInterface dict, final UserHistoryDictionaryBigramList bigrams) {
         final FusionDictionary fusionDict = new FusionDictionary(new Node(),
                 new FusionDictionary.DictionaryOptions(new HashMap<String, String>(), false,
@@ -193,7 +195,8 @@
     /**
      * Adds all unigrams and bigrams in maps to OnAddWordListener.
      */
-    /* package for test */ static void addWordsFromWordMap(final Map<Integer, String> unigrams,
+    @UsedForTesting
+    static void addWordsFromWordMap(final Map<Integer, String> unigrams,
             final Map<Integer, Integer> frequencies,
             final Map<Integer, ArrayList<PendingAttribute>> bigrams, final OnAddWordListener to) {
         for (Map.Entry<Integer, String> entry : unigrams.entrySet()) {
diff --git a/java/src/com/android/inputmethod/latin/UserHistoryDictionary.java b/java/src/com/android/inputmethod/latin/UserHistoryDictionary.java
index 3615fa1..4fd9bfa 100644
--- a/java/src/com/android/inputmethod/latin/UserHistoryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/UserHistoryDictionary.java
@@ -21,6 +21,7 @@
 import android.os.AsyncTask;
 import android.util.Log;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.ProximityInfo;
 import com.android.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
 import com.android.inputmethod.latin.UserHistoryDictIOUtils.BigramDictionaryInterface;
@@ -75,7 +76,7 @@
     private final SharedPreferences mPrefs;
 
     // Should always be false except when we use this class for test
-    /* package for test */ boolean isTest = false;
+    @UsedForTesting boolean isTest = false;
 
     private static final ConcurrentHashMap<String, SoftReference<UserHistoryDictionary>>
             sLangDictCache = CollectionUtils.newConcurrentHashMap();
@@ -122,7 +123,7 @@
 
     @Override
     protected ArrayList<SuggestedWordInfo> getWordsInner(final WordComposer composer,
-            final CharSequence prevWord, final ProximityInfo proximityInfo) {
+            final String prevWord, final ProximityInfo proximityInfo) {
         // Inhibit suggestions (not predictions) for user history for now. Removing this method
         // is enough to use it through the standard ExpandableDictionary way.
         return null;
@@ -132,7 +133,7 @@
      * Return whether the passed charsequence is in the dictionary.
      */
     @Override
-    public synchronized boolean isValidWord(final CharSequence word) {
+    public synchronized boolean isValidWord(final String word) {
         // TODO: figure out what is the correct thing to do here.
         return false;
     }
@@ -145,7 +146,7 @@
      * context, as in beginning of a sentence for example.
      * The second word may not be null (a NullPointerException would be thrown).
      */
-    public int addToUserHistory(final String word1, String word2, boolean isValid) {
+    public int addToUserHistory(final String word1, final String word2, final boolean isValid) {
         if (word2.length() >= BinaryDictionary.MAX_WORD_LENGTH ||
                 (word1 != null && word1.length() >= BinaryDictionary.MAX_WORD_LENGTH)) {
             return -1;
@@ -175,7 +176,7 @@
         return -1;
     }
 
-    public boolean cancelAddingUserHistory(String word1, String word2) {
+    public boolean cancelAddingUserHistory(final String word1, final String word2) {
         if (mBigramListLock.tryLock()) {
             try {
                 if (mBigramList.removeBigram(word1, word2)) {
@@ -226,7 +227,8 @@
         final ExpandableDictionary dictionary = this;
         final OnAddWordListener listener = new OnAddWordListener() {
             @Override
-            public void setUnigram(String word, String shortcutTarget, int frequency) {
+            public void setUnigram(final String word, final String shortcutTarget,
+                    final int frequency) {
                 profTotal++;
                 if (DBG_SAVE_RESTORE) {
                     Log.d(TAG, "load unigram: " + word + "," + frequency);
@@ -236,7 +238,7 @@
             }
 
             @Override
-            public void setBigram(String word1, String word2, int frequency) {
+            public void setBigram(final String word1, final String word2, final int frequency) {
                 if (word1.length() < BinaryDictionary.MAX_WORD_LENGTH
                         && word2.length() < BinaryDictionary.MAX_WORD_LENGTH) {
                     profTotal++;
@@ -250,7 +252,7 @@
                 mBigramList.addBigram(word1, word2, (byte)frequency);
             }
         };
-        
+
         // Load the dictionary from binary file
         FileInputStream inStream = null;
         try {
@@ -292,8 +294,9 @@
         private final SharedPreferences mPrefs;
         private final Context mContext;
 
-        public UpdateBinaryTask(UserHistoryDictionaryBigramList pendingWrites, String locale,
-                UserHistoryDictionary dict, SharedPreferences prefs, Context context) {
+        public UpdateBinaryTask(final UserHistoryDictionaryBigramList pendingWrites,
+                final String locale, final UserHistoryDictionary dict,
+                final SharedPreferences prefs, final Context context) {
             mBigramList = pendingWrites;
             mLocale = locale;
             mUserHistoryDictionary = dict;
@@ -303,7 +306,7 @@
         }
 
         @Override
-        protected Void doInBackground(Void... v) {
+        protected Void doInBackground(final Void... v) {
             if (mUserHistoryDictionary.isTest) {
                 // If isTest == true, wait until the lock is released.
                 mUserHistoryDictionary.mBigramListLock.lock();
@@ -360,7 +363,7 @@
         }
 
         @Override
-        public int getFrequency(String word1, String word2) {
+        public int getFrequency(final String word1, final String word2) {
             final int freq;
             if (word1 == null) { // unigram
                 freq = FREQUENCY_FOR_TYPED;
@@ -390,6 +393,7 @@
         }
     }
 
+    @UsedForTesting
     void forceAddWordForTest(final String word1, final String word2, final boolean isValid) {
         mBigramListLock.lock();
         try {
diff --git a/java/src/com/android/inputmethod/latin/WordComposer.java b/java/src/com/android/inputmethod/latin/WordComposer.java
index da0071a..229aa8a 100644
--- a/java/src/com/android/inputmethod/latin/WordComposer.java
+++ b/java/src/com/android/inputmethod/latin/WordComposer.java
@@ -38,7 +38,7 @@
     private int[] mPrimaryKeyCodes;
     private final InputPointers mInputPointers = new InputPointers(N);
     private final StringBuilder mTypedWord;
-    private CharSequence mAutoCorrection;
+    private String mAutoCorrection;
     private boolean mIsResumed;
     private boolean mIsBatchMode;
 
@@ -64,7 +64,7 @@
         refreshSize();
     }
 
-    public WordComposer(WordComposer source) {
+    public WordComposer(final WordComposer source) {
         mPrimaryKeyCodes = Arrays.copyOf(source.mPrimaryKeyCodes, source.mPrimaryKeyCodes.length);
         mTypedWord = new StringBuilder(source.mTypedWord);
         mInputPointers.copy(source.mInputPointers);
@@ -121,7 +121,8 @@
         return mInputPointers;
     }
 
-    private static boolean isFirstCharCapitalized(int index, int codePoint, boolean previous) {
+    private static boolean isFirstCharCapitalized(final int index, final int codePoint,
+            final boolean previous) {
         if (index == 0) return Character.isUpperCase(codePoint);
         return previous && !Character.isUpperCase(codePoint);
     }
@@ -129,7 +130,7 @@
     /**
      * Add a new keystroke, with the pressed key's code point with the touch point coordinates.
      */
-    public void add(int primaryCode, int keyX, int keyY) {
+    public void add(final int primaryCode, final int keyX, final int keyY) {
         final int newIndex = size();
         mTypedWord.appendCodePoint(primaryCode);
         refreshSize();
@@ -156,12 +157,12 @@
         mAutoCorrection = null;
     }
 
-    public void setBatchInputPointers(InputPointers batchPointers) {
+    public void setBatchInputPointers(final InputPointers batchPointers) {
         mInputPointers.set(batchPointers);
         mIsBatchMode = true;
     }
 
-    public void setBatchInputWord(CharSequence word) {
+    public void setBatchInputWord(final String word) {
         reset();
         mIsBatchMode = true;
         final int length = word.length();
@@ -321,14 +322,14 @@
     /**
      * Sets the auto-correction for this word.
      */
-    public void setAutoCorrection(final CharSequence correction) {
+    public void setAutoCorrection(final String correction) {
         mAutoCorrection = correction;
     }
 
     /**
      * @return the auto-correction for this word, or null if none.
      */
-    public CharSequence getAutoCorrectionOrNull() {
+    public String getAutoCorrectionOrNull() {
         return mAutoCorrection;
     }
 
@@ -341,7 +342,7 @@
 
     // `type' should be one of the LastComposedWord.COMMIT_TYPE_* constants above.
     public LastComposedWord commitWord(final int type, final String committedWord,
-            final String separatorString, final CharSequence prevWord) {
+            final String separatorString, final String prevWord) {
         // Note: currently, we come here whenever we commit a word. If it's a MANUAL_PICK
         // or a DECIDED_WORD we may cancel the commit later; otherwise, we should deactivate
         // the last composed word to ensure this does not happen.
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
index 40e089f..05f2d93 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
@@ -16,6 +16,7 @@
 
 package com.android.inputmethod.latin.makedict;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.makedict.BinaryDictInputOutput.CharEncoding;
 import com.android.inputmethod.latin.makedict.BinaryDictInputOutput.FusionDictionaryBufferInterface;
@@ -167,6 +168,7 @@
      * @throws IOException
      * @throws UnsupportedFormatException
      */
+    @UsedForTesting
     public static int getTerminalPosition(final FusionDictionaryBufferInterface buffer,
             final String word) throws IOException, UnsupportedFormatException {
         if (word == null) return FormatSpec.NOT_VALID_WORD;
@@ -254,6 +256,7 @@
      * @throws IOException
      * @throws UnsupportedFormatException
      */
+    @UsedForTesting
     public static void deleteWord(final FusionDictionaryBufferInterface buffer,
             final String word) throws IOException, UnsupportedFormatException {
         buffer.position(0);
@@ -706,6 +709,8 @@
      * @throws UnsupportedFormatException
      */
     // TODO: Support batch insertion.
+    // TODO: Remove @UsedForTesting once UserHistoryDictionary is implemented by BinaryDictionary.
+    @UsedForTesting
     public static void insertWord(final FusionDictionaryBufferInterface buffer,
             final OutputStream destination, final String word, final int frequency,
             final ArrayList<WeightedString> bigramStrings,
@@ -959,6 +964,7 @@
      * @throws IOException
      * @throws UnsupportedFormatException
      */
+    @UsedForTesting
     public static CharGroupInfo findWordFromBuffer(final FusionDictionaryBufferInterface buffer,
             final String word) throws IOException, UnsupportedFormatException {
         int position = getTerminalPosition(buffer, word);
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictInputOutput.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictInputOutput.java
index 2d39094..277796d 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictInputOutput.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictInputOutput.java
@@ -16,6 +16,7 @@
 
 package com.android.inputmethod.latin.makedict;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.CharGroup;
@@ -1651,6 +1652,7 @@
      * @param dict an optional dictionary to add words to, or null.
      * @return the created (or merged) dictionary.
      */
+    @UsedForTesting
     public static FusionDictionary readDictionaryBinary(
             final FusionDictionaryBufferInterface buffer, final FusionDictionary dict)
                     throws IOException, UnsupportedFormatException {
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
index 5a11ae5..49b9886 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
@@ -212,7 +212,7 @@
             }
         }
 
-        private final ArrayList<CharSequence> mSuggestions;
+        private final ArrayList<String> mSuggestions;
         private final int[] mScores;
         private final String mOriginalText;
         private final float mSuggestionThreshold;
@@ -335,7 +335,7 @@
                 gatheredSuggestions = mSuggestions.toArray(EMPTY_STRING_ARRAY);
 
                 final int bestScore = mScores[mLength - 1];
-                final CharSequence bestSuggestion = mSuggestions.get(0);
+                final String bestSuggestion = mSuggestions.get(0);
                 final float normalizedScore =
                         BinaryDictionary.calcNormalizedScore(
                                 mOriginalText, bestSuggestion.toString(), bestScore);
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/AndroidWordLevelSpellCheckerSession.java b/java/src/com/android/inputmethod/latin/spellcheck/AndroidWordLevelSpellCheckerSession.java
index 53ed4d3..a8f3239 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/AndroidWordLevelSpellCheckerSession.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/AndroidWordLevelSpellCheckerSession.java
@@ -268,7 +268,7 @@
                         dictInfo.mDictionary.getSuggestions(composer, prevWord,
                                 dictInfo.mProximityInfo);
                 for (final SuggestedWordInfo suggestion : suggestions) {
-                    final String suggestionStr = suggestion.mWord.toString();
+                    final String suggestionStr = suggestion.mWord;
                     suggestionsGatherer.addWord(suggestionStr.toCharArray(), null, 0,
                             suggestionStr.length(), suggestion.mScore);
                 }
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/DictionaryPool.java b/java/src/com/android/inputmethod/latin/spellcheck/DictionaryPool.java
index 1fb2bbb..eae5d2e 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/DictionaryPool.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/DictionaryPool.java
@@ -51,11 +51,11 @@
             new Dictionary(Dictionary.TYPE_MAIN) {
                 @Override
                 public ArrayList<SuggestedWordInfo> getSuggestions(final WordComposer composer,
-                        final CharSequence prevWord, final ProximityInfo proximityInfo) {
+                        final String prevWord, final ProximityInfo proximityInfo) {
                     return noSuggestions;
                 }
                 @Override
-                public boolean isValidWord(CharSequence word) {
+                public boolean isValidWord(final String word) {
                     // This is never called. However if for some strange reason it ever gets
                     // called, returning true is less destructive (it will not underline the
                     // word in red).
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java b/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
index 11bb970..6c0d79c 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/SpellCheckerProximityInfo.java
@@ -16,6 +16,7 @@
 
 package com.android.inputmethod.latin.spellcheck;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.keyboard.ProximityInfo;
 import com.android.inputmethod.latin.CollectionUtils;
 import com.android.inputmethod.latin.Constants;
@@ -23,7 +24,7 @@
 import java.util.TreeMap;
 
 public final class SpellCheckerProximityInfo {
-    /* public for test */
+    @UsedForTesting
     final public static int NUL = Constants.NOT_A_CODE;
 
     // This must be the same as MAX_PROXIMITY_CHARS_SIZE else it will not work inside
diff --git a/java/src/com/android/inputmethod/latin/suggestions/MoreSuggestions.java b/java/src/com/android/inputmethod/latin/suggestions/MoreSuggestions.java
index 4262695..35d5a00 100644
--- a/java/src/com/android/inputmethod/latin/suggestions/MoreSuggestions.java
+++ b/java/src/com/android/inputmethod/latin/suggestions/MoreSuggestions.java
@@ -65,7 +65,7 @@
             int pos = fromPos, rowStartPos = fromPos;
             final int size = Math.min(suggestions.size(), SuggestionStripView.MAX_SUGGESTIONS);
             while (pos < size) {
-                final String word = suggestions.getWord(pos).toString();
+                final String word = suggestions.getWord(pos);
                 // TODO: Should take care of text x-scaling.
                 mWidths[pos] = (int)view.getLabelWidth(word, paint) + padding;
                 final int numColumn = pos - rowStartPos + 1;
diff --git a/java/src/com/android/inputmethod/latin/suggestions/SuggestionStripView.java b/java/src/com/android/inputmethod/latin/suggestions/SuggestionStripView.java
index 3cf5857..e7cb97f 100644
--- a/java/src/com/android/inputmethod/latin/suggestions/SuggestionStripView.java
+++ b/java/src/com/android/inputmethod/latin/suggestions/SuggestionStripView.java
@@ -77,7 +77,7 @@
         OnLongClickListener {
     public interface Listener {
         public boolean addWordToUserDictionary(String word);
-        public void pickSuggestionManually(int index, CharSequence word);
+        public void pickSuggestionManually(int index, String word);
     }
 
     // The maximum number of suggestions available. See {@link Suggest#mPrefMaxSuggestions}.
@@ -286,7 +286,7 @@
 
         private CharSequence getStyledSuggestionWord(final SuggestedWords suggestedWords,
                 final int pos) {
-            final CharSequence word = suggestedWords.getWord(pos);
+            final String word = suggestedWords.getWord(pos);
             final boolean isAutoCorrect = pos == 1 && suggestedWords.willAutoCorrect();
             final boolean isTypedWordValid = pos == 0 && suggestedWords.mTypedWordValid;
             if (!isAutoCorrect && !isTypedWordValid)
@@ -338,7 +338,7 @@
                 // is in slot 1.
                 if (index == mCenterSuggestionIndex
                         && AutoCorrection.shouldBlockAutoCorrectionBySafetyNet(
-                                suggestedWords.getWord(1).toString(), suggestedWords.getWord(0))) {
+                                suggestedWords.getWord(1), suggestedWords.getWord(0))) {
                     return 0xFFFF0000;
                 }
             }
@@ -409,7 +409,7 @@
                 x += word.getMeasuredWidth();
 
                 if (DBG && pos < suggestedWords.size()) {
-                    final CharSequence debugInfo = Utils.getDebugInfo(suggestedWords, pos);
+                    final String debugInfo = Utils.getDebugInfo(suggestedWords, pos);
                     if (debugInfo != null) {
                         final TextView info = mInfos.get(pos);
                         info.setText(debugInfo);
@@ -466,7 +466,7 @@
                 final TextView word = mWords.get(index);
                 word.setEnabled(true);
                 word.setTextColor(mColorAutoCorrect);
-                final CharSequence text = suggestedWords.getWord(index);
+                final String text = suggestedWords.getWord(index);
                 word.setText(text);
                 word.setTextScaleX(1.0f);
                 word.setCompoundDrawables(null, null, null, null);
@@ -476,7 +476,7 @@
             mMoreSuggestionsAvailable = false;
         }
 
-        public void layoutAddToDictionaryHint(final CharSequence word, final ViewGroup stripView,
+        public void layoutAddToDictionaryHint(final String word, final ViewGroup stripView,
                 final int stripWidth, final CharSequence hintText, final OnClickListener listener) {
             final int width = stripWidth - mDividerWidth - mPadding * 2;
 
@@ -690,7 +690,7 @@
                 && mParams.isAddToDictionaryShowing(mSuggestionsStrip.getChildAt(0));
     }
 
-    public void showAddToDictionaryHint(final CharSequence word, final CharSequence hintText) {
+    public void showAddToDictionaryHint(final String word, final CharSequence hintText) {
         clear();
         mParams.layoutAddToDictionaryHint(word, mSuggestionsStrip, getWidth(), hintText, this);
     }
@@ -723,7 +723,7 @@
         @Override
         public boolean onCustomRequest(final int requestCode) {
             final int index = requestCode;
-            final CharSequence word = mSuggestedWords.getWord(index);
+            final String word = mSuggestedWords.getWord(index);
             mListener.pickSuggestionManually(index, word);
             dismissMoreSuggestions();
             return true;
@@ -871,7 +871,7 @@
         if (index >= mSuggestedWords.size())
             return;
 
-        final CharSequence word = mSuggestedWords.getWord(index);
+        final String word = mSuggestedWords.getWord(index);
         mListener.pickSuggestionManually(index, word);
     }
 
diff --git a/tests/src/com/android/inputmethod/latin/InputTestsBase.java b/tests/src/com/android/inputmethod/latin/InputTestsBase.java
index eb50020..7033050 100644
--- a/tests/src/com/android/inputmethod/latin/InputTestsBase.java
+++ b/tests/src/com/android/inputmethod/latin/InputTestsBase.java
@@ -281,7 +281,7 @@
         waitForDictionaryToBeLoaded();
     }
 
-    protected void pickSuggestionManually(final int index, final CharSequence suggestion) {
+    protected void pickSuggestionManually(final int index, final String suggestion) {
         mLatinIME.pickSuggestionManually(index, suggestion);
     }
 
diff --git a/tools/dicttool/Android.mk b/tools/dicttool/Android.mk
index 5bd836a..159c1c1 100644
--- a/tools/dicttool/Android.mk
+++ b/tools/dicttool/Android.mk
@@ -16,14 +16,18 @@
 LOCAL_PATH := $(call my-dir)
 include $(CLEAR_VARS)
 
-LATINIME_CORE_SOURCE_DIRECTORY := ../../java/src/com/android/inputmethod/latin
+LATINIME_BASE_SOURCE_DIRECTORY := ../../java/src/com/android/inputmethod
+LATINIME_CORE_SOURCE_DIRECTORY := $(LATINIME_BASE_SOURCE_DIRECTORY)/latin
+LATINIME_ANNOTATIONS_SOURCE_DIRECTORY := $(LATINIME_BASE_SOURCE_DIRECTORY)/annotations
 MAKEDICT_CORE_SOURCE_DIRECTORY := $(LATINIME_CORE_SOURCE_DIRECTORY)/makedict
 
 LOCAL_MAIN_SRC_FILES := $(call all-java-files-under,$(MAKEDICT_CORE_SOURCE_DIRECTORY))
 LOCAL_TOOL_SRC_FILES := $(call all-java-files-under,src)
+LOCAL_ANNOTATIONS_SRC_FILES := $(call all-java-files-under,$(LATINIME_ANNOTATIONS_SOURCE_DIRECTORY))
 LOCAL_SRC_FILES := $(LOCAL_TOOL_SRC_FILES) \
         $(filter-out $(addprefix %/, $(notdir $(LOCAL_TOOL_SRC_FILES))), $(LOCAL_MAIN_SRC_FILES)) \
         $(call all-java-files-under,tests) \
+        $(LOCAL_ANNOTATIONS_SRC_FILES) \
         $(LATINIME_CORE_SOURCE_DIRECTORY)/Constants.java
 
 LOCAL_JAR_MANIFEST := etc/manifest.txt
diff --git a/tools/dicttool/tests/com/android/inputmethod/latin/makedict/BinaryDictInputOutputTest.java b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/BinaryDictInputOutputTest.java
index 88589b8..0969028 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/makedict/BinaryDictInputOutputTest.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/makedict/BinaryDictInputOutputTest.java
@@ -19,24 +19,15 @@
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary.Node;
 
+import junit.framework.TestCase;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 
-import junit.framework.TestCase;
-
 /**
  * Unit tests for BinaryDictInputOutput.
  */
 public class BinaryDictInputOutputTest extends TestCase {
-
-    public void setUp() throws Exception {
-        super.setUp();
-    }
-
-    public void tearDown() throws Exception {
-        super.tearDown();
-    }
-
     // Test the flattened array contains the expected number of nodes, and
     // that it does not contain any duplicates.
     public void testFlattenNodes() {
@@ -55,5 +46,4 @@
             assertFalse("Flattened array contained the same node twice", result.contains(n));
         }
     }
-
 }
diff --git a/tools/dicttool/tests/etc/test-dicttool.sh b/tools/dicttool/tests/etc/test-dicttool.sh
index 8834611..1283be2 100755
--- a/tools/dicttool/tests/etc/test-dicttool.sh
+++ b/tools/dicttool/tests/etc/test-dicttool.sh
@@ -13,4 +13,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-java -classpath ${ANDROID_HOST_OUT}/framework/junit.jar:${ANDROID_HOST_OUT}/../common/obj/JAVA_LIBRARIES/dicttool_intermediates/classes junit.textui.TestRunner com.android.inputmethod.latin.makedict.BinaryDictInputOutputTest
+java -classpath ${ANDROID_HOST_OUT}/framework/junit.jar:${ANDROID_HOST_OUT}/framework/dicttool_aosp.jar junit.textui.TestRunner com.android.inputmethod.latin.makedict.BinaryDictInputOutputTest
diff --git a/tools/maketext/res/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.tmpl b/tools/maketext/res/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.tmpl
index 774094c..15aea90 100644
--- a/tools/maketext/res/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.tmpl
+++ b/tools/maketext/res/com/android/inputmethod/keyboard/internal/KeyboardTextsSet.tmpl
@@ -19,6 +19,7 @@
 import android.content.Context;
 import android.content.res.Resources;
 
+import com.android.inputmethod.annotations.VisibleForTesting;
 import com.android.inputmethod.latin.CollectionUtils;
 import com.android.inputmethod.latin.R;
 
@@ -64,7 +65,7 @@
         loadStringResourcesInternal(context, RESOURCE_NAMES, R.string.english_ime_name);
     }
 
-    /* package for test */
+    @VisibleForTesting
     void loadStringResourcesInternal(Context context, final String[] resourceNames,
             int referenceId) {
         final Resources res = context.getResources();