diff --git a/java/src/com/android/inputmethod/compat/InputMethodManagerCompatWrapper.java b/java/src/com/android/inputmethod/compat/InputMethodManagerCompatWrapper.java
index 51dc4cd..0e5f8c8 100644
--- a/java/src/com/android/inputmethod/compat/InputMethodManagerCompatWrapper.java
+++ b/java/src/com/android/inputmethod/compat/InputMethodManagerCompatWrapper.java
@@ -153,8 +153,7 @@
         return Utils.getInputMethodInfo(this, mLatinImePackageName);
     }
 
-    @SuppressWarnings("unused")
-    private InputMethodSubtypeCompatWrapper getLastResortSubtype(String mode) {
+    private static InputMethodSubtypeCompatWrapper getLastResortSubtype(String mode) {
         if (VOICE_MODE.equals(mode) && !FORCE_ENABLE_VOICE_EVEN_WITH_NO_VOICE_SUBTYPES)
             return null;
         Locale inputLocale = SubtypeSwitcher.getInstance().getInputLocale();
diff --git a/java/src/com/android/inputmethod/keyboard/Key.java b/java/src/com/android/inputmethod/keyboard/Key.java
index f1ae0b3..f2014b7 100644
--- a/java/src/com/android/inputmethod/keyboard/Key.java
+++ b/java/src/com/android/inputmethod/keyboard/Key.java
@@ -223,7 +223,7 @@
             if (style == null)
                 throw new ParseException("Unknown key style: " + styleName, parser);
         } else {
-            style = keyStyles.getEmptyKeyStyle();
+            style = KeyStyles.getEmptyKeyStyle();
         }
 
         final float keyXPos = row.getKeyX(keyAttr);
diff --git a/java/src/com/android/inputmethod/keyboard/internal/KeyStyles.java b/java/src/com/android/inputmethod/keyboard/internal/KeyStyles.java
index b385b7a..39fb521 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/KeyStyles.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/KeyStyles.java
@@ -235,7 +235,7 @@
         return mStyles.get(styleName);
     }
 
-    public KeyStyle getEmptyKeyStyle() {
+    public static KeyStyle getEmptyKeyStyle() {
         return EMPTY_KEY_STYLE;
     }
 }
diff --git a/java/src/com/android/inputmethod/latin/AutoCorrection.java b/java/src/com/android/inputmethod/latin/AutoCorrection.java
index 485ec51..cd066a3 100644
--- a/java/src/com/android/inputmethod/latin/AutoCorrection.java
+++ b/java/src/com/android/inputmethod/latin/AutoCorrection.java
@@ -98,7 +98,7 @@
         return whiteListedWord != null;
     }
 
-    private boolean hasAutoCorrectionForTypedWord(Map<String, Dictionary> dictionaries,
+    private static boolean hasAutoCorrectionForTypedWord(Map<String, Dictionary> dictionaries,
             WordComposer wordComposer, ArrayList<CharSequence> suggestions, CharSequence typedWord,
             int correctionMode) {
         if (TextUtils.isEmpty(typedWord)) return false;
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 0498fd3..5b7428e 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -382,6 +382,8 @@
         private boolean mHasPendingFinishInput;
 
         public void startOrientationChanging() {
+            removeMessages(MSG_PENDING_IMS_CALLBACK);
+            resetPendingImsCallback();
             mIsOrientationChanging = true;
             final LatinIME latinIme = getOuterInstance();
             latinIme.mKeyboardSwitcher.saveKeyboardState();
@@ -1178,7 +1180,7 @@
     }
 
     // "ic" must not be null
-    private void maybeRemovePreviousPeriod(final InputConnection ic, CharSequence text) {
+    private static void maybeRemovePreviousPeriod(final InputConnection ic, CharSequence text) {
         // When the text's first character is '.', remove the previous period
         // if there is one.
         final CharSequence lastOne = ic.getTextBeforeCursor(1, 0);
@@ -1190,7 +1192,7 @@
     }
 
     // "ic" may be null
-    private void removeTrailingSpaceWhileInBatchEdit(final InputConnection ic) {
+    private static void removeTrailingSpaceWhileInBatchEdit(final InputConnection ic) {
         if (ic == null) return;
         final CharSequence lastOne = ic.getTextBeforeCursor(1, 0);
         if (lastOne != null && lastOne.length() == 1
@@ -1208,12 +1210,8 @@
         return true;
     }
 
-    private boolean isAlphabet(int code) {
-        if (Character.isLetter(code)) {
-            return true;
-        } else {
-            return false;
-        }
+    private static boolean isAlphabet(int code) {
+        return Character.isLetter(code);
     }
 
     private void onSettingsKeyPressed() {
@@ -2076,7 +2074,7 @@
     }
 
     // "ic" must not be null
-    private boolean sameAsTextBeforeCursor(final InputConnection ic, CharSequence text) {
+    private static boolean sameAsTextBeforeCursor(final InputConnection ic, CharSequence text) {
         CharSequence beforeText = ic.getTextBeforeCursor(text.length(), 0);
         return TextUtils.equals(text, beforeText);
     }
@@ -2130,7 +2128,7 @@
         return true;
     }
 
-    private boolean revertSwapPunctuation(final InputConnection ic) {
+    private static boolean revertSwapPunctuation(final InputConnection ic) {
         // Here we test whether we indeed have a space and something else before us. This should not
         // be needed, but it's there just in case something went wrong.
         final CharSequence textBeforeCursor = ic.getTextBeforeCursor(2, 0);
diff --git a/java/src/com/android/inputmethod/latin/Suggest.java b/java/src/com/android/inputmethod/latin/Suggest.java
index caa5aac..97e9174 100644
--- a/java/src/com/android/inputmethod/latin/Suggest.java
+++ b/java/src/com/android/inputmethod/latin/Suggest.java
@@ -144,7 +144,7 @@
         initWhitelistAndAutocorrectAndPool(context, locale);
     }
 
-    private void addOrReplaceDictionary(Map<String, Dictionary> dictionaries, String key,
+    private static void addOrReplaceDictionary(Map<String, Dictionary> dictionaries, String key,
             Dictionary dict) {
         final Dictionary oldDict = (dict == null)
                 ? dictionaries.remove(key)
@@ -518,7 +518,8 @@
         return -1;
     }
 
-    private void collectGarbage(ArrayList<CharSequence> suggestions, int prefMaxSuggestions) {
+    private static void collectGarbage(ArrayList<CharSequence> suggestions,
+            int prefMaxSuggestions) {
         int poolSize = StringBuilderPool.getSize();
         int garbageSize = suggestions.size();
         while (poolSize < prefMaxSuggestions && garbageSize > 0) {
diff --git a/java/src/com/android/inputmethod/latin/UserBigramDictionary.java b/java/src/com/android/inputmethod/latin/UserBigramDictionary.java
index 9e65667..3a1af93 100644
--- a/java/src/com/android/inputmethod/latin/UserBigramDictionary.java
+++ b/java/src/com/android/inputmethod/latin/UserBigramDictionary.java
@@ -238,7 +238,7 @@
     /**
      * Query the database
      */
-    private Cursor query(String selection, String[] selectionArgs) {
+    private static Cursor query(String selection, String[] selectionArgs) {
         SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
 
         // main INNER JOIN frequency ON (main._id=freq.pair_id)
@@ -310,7 +310,7 @@
         }
 
         /** Prune any old data if the database is getting too big. */
-        private void checkPruneData(SQLiteDatabase db) {
+        private static void checkPruneData(SQLiteDatabase db) {
             db.execSQL("PRAGMA foreign_keys = ON;");
             Cursor c = db.query(FREQ_TABLE_NAME, new String[] { FREQ_COLUMN_PAIR_ID },
                     null, null, null, null, null);
@@ -380,7 +380,7 @@
             return null;
         }
 
-        private ContentValues getContentValues(String word1, String word2, String locale) {
+        private static ContentValues getContentValues(String word1, String word2, String locale) {
             ContentValues values = new ContentValues(3);
             values.put(MAIN_COLUMN_WORD1, word1);
             values.put(MAIN_COLUMN_WORD2, word2);
@@ -388,7 +388,7 @@
             return values;
         }
 
-        private ContentValues getFrequencyContentValues(int pairId, int frequency) {
+        private static ContentValues getFrequencyContentValues(int pairId, int frequency) {
            ContentValues values = new ContentValues(2);
            values.put(FREQ_COLUMN_PAIR_ID, pairId);
            values.put(FREQ_COLUMN_FREQUENCY, frequency);
diff --git a/java/src/com/android/inputmethod/latin/UserUnigramDictionary.java b/java/src/com/android/inputmethod/latin/UserUnigramDictionary.java
index e41230b..de7cb57 100644
--- a/java/src/com/android/inputmethod/latin/UserUnigramDictionary.java
+++ b/java/src/com/android/inputmethod/latin/UserUnigramDictionary.java
@@ -206,7 +206,7 @@
         }
     }
 
-    private Cursor query(String selection, String[] selectionArgs) {
+    private static Cursor query(String selection, String[] selectionArgs) {
         SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
         qb.setTables(USER_UNIGRAM_DICT_TABLE_NAME);
         qb.setProjectionMap(sDictProjectionMap);
@@ -251,7 +251,7 @@
             return null;
         }
 
-        private ContentValues getContentValues(String word, int frequency, String locale) {
+        private static ContentValues getContentValues(String word, int frequency, String locale) {
             ContentValues values = new ContentValues(4);
             values.put(COLUMN_WORD, word);
             values.put(COLUMN_FREQUENCY, frequency);
diff --git a/java/src/com/android/inputmethod/latin/Utils.java b/java/src/com/android/inputmethod/latin/Utils.java
index b29ff19..3d0aa09 100644
--- a/java/src/com/android/inputmethod/latin/Utils.java
+++ b/java/src/com/android/inputmethod/latin/Utils.java
@@ -242,7 +242,7 @@
             UsabilityStudyLogUtils.getInstance().init(context);
             return sRingCharBuffer;
         }
-        private int normalize(int in) {
+        private static int normalize(int in) {
             int ret = in % BUFSIZE;
             return ret < 0 ? ret + BUFSIZE : ret;
         }
@@ -465,7 +465,7 @@
             }
         }
 
-        public void writeBackSpace() {
+        public static void writeBackSpace() {
             UsabilityStudyLogUtils.getInstance().write("<backspace>\t0\t0");
         }
 
diff --git a/java/src/com/android/inputmethod/latin/WordComposer.java b/java/src/com/android/inputmethod/latin/WordComposer.java
index adc5637..7f3a542 100644
--- a/java/src/com/android/inputmethod/latin/WordComposer.java
+++ b/java/src/com/android/inputmethod/latin/WordComposer.java
@@ -135,7 +135,7 @@
      * @param primaryCode the preferred character
      * @param codes array of codes based on distance from touch point
      */
-    private void correctPrimaryJuxtapos(int primaryCode, int[] codes) {
+    private static void correctPrimaryJuxtapos(int primaryCode, int[] codes) {
         if (codes.length < 2) return;
         if (codes[0] > 0 && codes[1] > 0 && codes[0] != primaryCode && codes[1] == primaryCode) {
             codes[1] = codes[0];
diff --git a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
index 095c2c5..5d296f8 100644
--- a/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
+++ b/java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java
@@ -368,7 +368,7 @@
          * @param text the string to evaluate.
          * @return true if we should filter this text out, false otherwise
          */
-        private boolean shouldFilterOut(final String text) {
+        private static boolean shouldFilterOut(final String text) {
             if (TextUtils.isEmpty(text) || text.length() <= 1) return true;
 
             // TODO: check if an equivalent processing can't be done more quickly with a
diff --git a/native/jni/com_android_inputmethod_keyboard_ProximityInfo.cpp b/native/jni/com_android_inputmethod_keyboard_ProximityInfo.cpp
index 595ea2f..d64c337 100644
--- a/native/jni/com_android_inputmethod_keyboard_ProximityInfo.cpp
+++ b/native/jni/com_android_inputmethod_keyboard_ProximityInfo.cpp
@@ -35,7 +35,7 @@
         jintArray keyHeightArray, jintArray keyCharCodeArray,
         jfloatArray sweetSpotCenterXArray, jfloatArray sweetSpotCenterYArray,
         jfloatArray sweetSpotRadiusArray) {
-    jint *proximityChars = env->GetIntArrayElements(proximityCharsArray, NULL);
+    jint *proximityChars = env->GetIntArrayElements(proximityCharsArray, 0);
     jint *keyXCoordinates = safeGetIntArrayElements(env, keyXCoordinateArray);
     jint *keyYCoordinates = safeGetIntArrayElements(env, keyYCoordinateArray);
     jint *keyWidths = safeGetIntArrayElements(env, keyWidthArray);
diff --git a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
index 18c9724..6f43f9c 100644
--- a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
+++ b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <unistd.h>
 #else // USE_MMAP_FOR_DICTIONARY
 #include <stdlib.h>
 #endif // USE_MMAP_FOR_DICTIONARY
@@ -47,13 +48,13 @@
         jint maxAlternatives) {
     PROF_OPEN;
     PROF_START(66);
-    const char *sourceDirChars = env->GetStringUTFChars(sourceDir, NULL);
-    if (sourceDirChars == NULL) {
+    const char *sourceDirChars = env->GetStringUTFChars(sourceDir, 0);
+    if (sourceDirChars == 0) {
         LOGE("DICT: Can't get sourceDir string");
         return 0;
     }
     int fd = 0;
-    void *dictBuf = NULL;
+    void *dictBuf = 0;
     int adjust = 0;
 #ifdef USE_MMAP_FOR_DICTIONARY
     /* mmap version */
@@ -66,7 +67,7 @@
     adjust = dictOffset % pagesize;
     int adjDictOffset = dictOffset - adjust;
     int adjDictSize = dictSize + adjust;
-    dictBuf = mmap(NULL, sizeof(char) * adjDictSize, PROT_READ, MAP_PRIVATE, fd, adjDictOffset);
+    dictBuf = mmap(0, sizeof(char) * adjDictSize, PROT_READ, MAP_PRIVATE, fd, adjDictOffset);
     if (dictBuf == MAP_FAILED) {
         LOGE("DICT: Can't mmap dictionary. errno=%d", errno);
         return 0;
@@ -74,9 +75,9 @@
     dictBuf = (void *)((char *)dictBuf + adjust);
 #else // USE_MMAP_FOR_DICTIONARY
     /* malloc version */
-    FILE *file = NULL;
+    FILE *file = 0;
     file = fopen(sourceDirChars, "rb");
-    if (file == NULL) {
+    if (file == 0) {
         LOGE("DICT: Can't fopen sourceDir. sourceDirChars=%s errno=%d", sourceDirChars, errno);
         return 0;
     }
@@ -107,7 +108,7 @@
         LOGE("DICT: dictBuf is null");
         return 0;
     }
-    Dictionary *dictionary = NULL;
+    Dictionary *dictionary = 0;
     if (BinaryFormat::UNKNOWN_FORMAT == BinaryFormat::detectFormat((uint8_t*)dictBuf)) {
         LOGE("DICT: dictionary format is unknown, bad magic number");
 #ifdef USE_MMAP_FOR_DICTIONARY
@@ -132,12 +133,12 @@
     if (!dictionary) return 0;
     ProximityInfo *pInfo = (ProximityInfo*)proximityInfo;
 
-    int *xCoordinates = env->GetIntArrayElements(xCoordinatesArray, NULL);
-    int *yCoordinates = env->GetIntArrayElements(yCoordinatesArray, NULL);
+    int *xCoordinates = env->GetIntArrayElements(xCoordinatesArray, 0);
+    int *yCoordinates = env->GetIntArrayElements(yCoordinatesArray, 0);
 
-    int *frequencies = env->GetIntArrayElements(frequencyArray, NULL);
-    int *inputCodes = env->GetIntArrayElements(inputArray, NULL);
-    jchar *outputChars = env->GetCharArrayElements(outputArray, NULL);
+    int *frequencies = env->GetIntArrayElements(frequencyArray, 0);
+    int *inputCodes = env->GetIntArrayElements(inputArray, 0);
+    jchar *outputChars = env->GetCharArrayElements(outputArray, 0);
 
     int count = dictionary->getSuggestions(pInfo, xCoordinates, yCoordinates, inputCodes,
             arraySize, flags, (unsigned short*) outputChars, frequencies);
@@ -158,10 +159,10 @@
     Dictionary *dictionary = (Dictionary*)dict;
     if (!dictionary) return 0;
 
-    jchar *prevWord = env->GetCharArrayElements(prevWordArray, NULL);
-    int *inputCodes = env->GetIntArrayElements(inputArray, NULL);
-    jchar *outputChars = env->GetCharArrayElements(outputArray, NULL);
-    int *frequencies = env->GetIntArrayElements(frequencyArray, NULL);
+    jchar *prevWord = env->GetCharArrayElements(prevWordArray, 0);
+    int *inputCodes = env->GetIntArrayElements(inputArray, 0);
+    jchar *outputChars = env->GetCharArrayElements(outputArray, 0);
+    int *frequencies = env->GetIntArrayElements(frequencyArray, 0);
 
     int count = dictionary->getBigrams((unsigned short*) prevWord, prevWordLength, inputCodes,
             inputArraySize, (unsigned short*) outputChars, frequencies, maxWordLength, maxBigrams,
@@ -180,7 +181,7 @@
     Dictionary *dictionary = (Dictionary*)dict;
     if (!dictionary) return (jboolean) false;
 
-    jchar *word = env->GetCharArrayElements(wordArray, NULL);
+    jchar *word = env->GetCharArrayElements(wordArray, 0);
     jboolean result = dictionary->isValidWord((unsigned short*) word, wordLength);
     env->ReleaseCharArrayElements(wordArray, word, JNI_ABORT);
 
diff --git a/native/jni/jni_common.cpp b/native/jni/jni_common.cpp
index 8643f72..958abfd 100644
--- a/native/jni/jni_common.cpp
+++ b/native/jni/jni_common.cpp
@@ -32,14 +32,14 @@
  * Returns the JNI version on success, -1 on failure.
  */
 jint JNI_OnLoad(JavaVM* vm, void* reserved) {
-    JNIEnv* env = NULL;
+    JNIEnv* env = 0;
     jint result = -1;
 
     if (vm->GetEnv((void**) &env, JNI_VERSION_1_4) != JNI_OK) {
         LOGE("ERROR: GetEnv failed");
         goto bail;
     }
-    assert(env != NULL);
+    assert(env != 0);
 
     if (!register_BinaryDictionary(env)) {
         LOGE("ERROR: BinaryDictionary native registration failed");
@@ -63,7 +63,7 @@
 int registerNativeMethods(JNIEnv* env, const char* className, JNINativeMethod* methods,
         int numMethods) {
     jclass clazz = env->FindClass(className);
-    if (clazz == NULL) {
+    if (clazz == 0) {
         LOGE("Native registration unable to find class '%s'", className);
         return JNI_FALSE;
     }
diff --git a/native/jni/jni_common.h b/native/jni/jni_common.h
index 9548e1b..6741443 100644
--- a/native/jni/jni_common.h
+++ b/native/jni/jni_common.h
@@ -29,17 +29,17 @@
 
 inline jint *safeGetIntArrayElements(JNIEnv *env, jintArray jArray) {
     if (jArray) {
-        return env->GetIntArrayElements(jArray, NULL);
+        return env->GetIntArrayElements(jArray, 0);
     } else {
-        return NULL;
+        return 0;
     }
 }
 
 inline jfloat *safeGetFloatArrayElements(JNIEnv *env, jfloatArray jArray) {
     if (jArray) {
-        return env->GetFloatArrayElements(jArray, NULL);
+        return env->GetFloatArrayElements(jArray, 0);
     } else {
-        return NULL;
+        return 0;
     }
 }
 
diff --git a/native/src/correction.cpp b/native/src/correction.cpp
index 0c56680..f6b7eb6 100644
--- a/native/src/correction.cpp
+++ b/native/src/correction.cpp
@@ -87,7 +87,7 @@
     int *const current = editDistanceTable + outputLength * (inputLength + 1);
     const int *const prev = editDistanceTable + (outputLength - 1) * (inputLength + 1);
     const int *const prevprev =
-            outputLength >= 2 ? editDistanceTable + (outputLength - 2) * (inputLength + 1) : NULL;
+            outputLength >= 2 ? editDistanceTable + (outputLength - 2) * (inputLength + 1) : 0;
     current[0] = outputLength;
     const uint32_t co = Dictionary::toBaseLowerCase(output[outputLength - 1]);
     const uint32_t prevCO =
diff --git a/native/src/proximity_info.cpp b/native/src/proximity_info.cpp
index 20fa18a..2f989e3 100644
--- a/native/src/proximity_info.cpp
+++ b/native/src/proximity_info.cpp
@@ -47,7 +47,7 @@
           HAS_TOUCH_POSITION_CORRECTION_DATA(keyCount > 0 && keyXCoordinates && keyYCoordinates
                   && keyWidths && keyHeights && keyCharCodes && sweetSpotCenterXs
                   && sweetSpotCenterYs && sweetSpotRadii),
-          mInputXCoordinates(NULL), mInputYCoordinates(NULL),
+          mInputXCoordinates(0), mInputYCoordinates(0),
           mTouchPositionCorrectionEnabled(false) {
     const int len = GRID_WIDTH * GRID_HEIGHT * MAX_PROXIMITY_CHARS_SIZE;
     mProximityCharsArray = new uint32_t[len];
diff --git a/native/src/proximity_info.h b/native/src/proximity_info.h
index 35e354c..832db10 100644
--- a/native/src/proximity_info.h
+++ b/native/src/proximity_info.h
@@ -56,7 +56,7 @@
     bool existsCharInProximityAt(const int index, const int c) const;
     bool existsAdjacentProximityChars(const int index) const;
     ProximityType getMatchedProximityId(const int index, const unsigned short c,
-            const bool checkProximityChars, int *proximityIndex = NULL) const;
+            const bool checkProximityChars, int *proximityIndex = 0) const;
     int getNormalizedSquaredDistance(const int inputIndex, const int proximityIndex) const {
         return mNormalizedSquaredDistances[inputIndex * MAX_PROXIMITY_CHARS_SIZE + proximityIndex];
     }
diff --git a/native/src/unigram_dictionary.h b/native/src/unigram_dictionary.h
index ef9709a..4f4fef2 100644
--- a/native/src/unigram_dictionary.h
+++ b/native/src/unigram_dictionary.h
@@ -23,10 +23,6 @@
 #include "defines.h"
 #include "proximity_info.h"
 
-#ifndef NULL
-#define NULL 0
-#endif
-
 namespace latinime {
 
 class UnigramDictionary {