Remove next letters frequency handling

Bug: 3428942
Change-Id: Id62f467ce4e50c60a56d59bf96770e799a4659e2

7 files changed, 23 insertions, 61 deletions

diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index a7e95a080..ff7e2b88a 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -118,8 +118,7 @@ public class BinaryDictionary extends Dictionary {
     private native void closeNative(int dict);
     private native boolean isValidWordNative(int nativeData, char[] word, int wordLength);
     private native int getSuggestionsNative(int dict, int[] inputCodes, int codesSize,
-            char[] outputChars, int[] frequencies,
-            int[] nextLettersFrequencies, int nextLettersSize);
+            char[] outputChars, int[] frequencies);
     private native int getBigramsNative(int dict, char[] prevWord, int prevWordLength,
             int[] inputCodes, int inputCodesLength, char[] outputChars, int[] frequencies,
             int maxWordLength, int maxBigrams, int maxAlternatives);
@@ -133,7 +132,7 @@ public class BinaryDictionary extends Dictionary {
 
     @Override
     public void getBigrams(final WordComposer codes, final CharSequence previousWord,
-            final WordCallback callback, int[] nextLettersFrequencies) {
+            final WordCallback callback) {
         if (mNativeDict == 0) return;
 
         char[] chars = previousWord.toString().toCharArray();
@@ -165,15 +164,14 @@ public class BinaryDictionary extends Dictionary {
     }
 
     @Override
-    public void getWords(final WordComposer codes, final WordCallback callback,
-            int[] nextLettersFrequencies) {
+    public void getWords(final WordComposer codes, final WordCallback callback) {
         if (mNativeDict == 0) return;
 
         final int codesSize = codes.size();
         // Won't deal with really long words.
         if (codesSize > MAX_WORD_LENGTH - 1) return;
 
-        Arrays.fill(mInputCodes, -1);
+        Arrays.fill(mInputCodes, WordComposer.NOT_A_CODE);
         for (int i = 0; i < codesSize; i++) {
             int[] alternatives = codes.getCodesAt(i);
             System.arraycopy(alternatives, 0, mInputCodes, i * MAX_ALTERNATIVES,
@@ -183,8 +181,7 @@ public class BinaryDictionary extends Dictionary {
         Arrays.fill(mFrequencies, 0);
 
         int count = getSuggestionsNative(mNativeDict, mInputCodes, codesSize, mOutputChars,
-                mFrequencies, nextLettersFrequencies,
-                nextLettersFrequencies != null ? nextLettersFrequencies.length : 0);
+                mFrequencies);
 
         for (int j = 0; j < count; ++j) {
             if (mFrequencies[j] < 1) break;
diff --git a/java/src/com/android/inputmethod/latin/Dictionary.java b/java/src/com/android/inputmethod/latin/Dictionary.java
index 74933595c..56f0cc503 100644
--- a/java/src/com/android/inputmethod/latin/Dictionary.java
+++ b/java/src/com/android/inputmethod/latin/Dictionary.java
@@ -61,14 +61,9 @@ public abstract class Dictionary {
      * words are added through the callback object.
      * @param composer the key sequence to match
      * @param callback the callback object to send matched words to as possible candidates
-     * @param nextLettersFrequencies array of frequencies of next letters that could follow the
-     *        word so far. For instance, "bracke" can be followed by "t", so array['t'] will have
-     *        a non-zero value on returning from this method. 
-     *        Pass in null if you don't want the dictionary to look up next letters.
      * @see WordCallback#addWord(char[], int, int)
      */
-    abstract public void getWords(final WordComposer composer, final WordCallback callback,
-            int[] nextLettersFrequencies);
+    abstract public void getWords(final WordComposer composer, final WordCallback callback);
 
     /**
      * Searches for pairs in the bigram dictionary that matches the previous word and all the
@@ -76,13 +71,9 @@ public abstract class Dictionary {
      * @param composer the key sequence to match
      * @param previousWord the word before
      * @param callback the callback object to send possible word following previous word
-     * @param nextLettersFrequencies array of frequencies of next letters that could follow the
-     *        word so far. For instance, "bracke" can be followed by "t", so array['t'] will have
-     *        a non-zero value on returning from this method.
-     *        Pass in null if you don't want the dictionary to look up next letters.
      */
     public void getBigrams(final WordComposer composer, final CharSequence previousWord,
-            final WordCallback callback, int[] nextLettersFrequencies) {
+            final WordCallback callback) {
         // empty base implementation
     }
 
diff --git a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
index 0fc86c335..b10e7a61e 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
@@ -37,7 +37,6 @@ public class ExpandableDictionary extends Dictionary {
     private int mDicTypeId;
     private int mMaxDepth;
     private int mInputLength;
-    private int[] mNextLettersFrequencies;
     private StringBuilder sb = new StringBuilder(MAX_WORD_LENGTH);
 
     private static final char QUOTE = '\'';
@@ -191,8 +190,7 @@ public class ExpandableDictionary extends Dictionary {
     }
 
     @Override
-    public void getWords(final WordComposer codes, final WordCallback callback,
-            int[] nextLettersFrequencies) {
+    public void getWords(final WordComposer codes, final WordCallback callback) {
         synchronized (mUpdatingLock) {
             // If we need to update, start off a background task
             if (mRequiresReload) startDictionaryLoadingTaskLocked();
@@ -201,7 +199,6 @@ public class ExpandableDictionary extends Dictionary {
         }
 
         mInputLength = codes.size();
-        mNextLettersFrequencies = nextLettersFrequencies;
         if (mCodes.length < mInputLength) mCodes = new int[mInputLength][];
         // Cache the codes so that we don't have to lookup an array list
         for (int i = 0; i < mInputLength; i++) {
@@ -282,11 +279,6 @@ public class ExpandableDictionary extends Dictionary {
                                 DataType.UNIGRAM)) {
                         return;
                     }
-                    // Add to frequency of next letters for predictive correction
-                    if (mNextLettersFrequencies != null && depth >= inputIndex && skipPos < 0
-                            && mNextLettersFrequencies.length > word[inputIndex]) {
-                        mNextLettersFrequencies[word[inputIndex]]++;
-                    }
                 }
                 if (children != null) {
                     getWordsRec(children, codes, word, depth + 1, completion, snr, inputIndex,
@@ -427,7 +419,7 @@ public class ExpandableDictionary extends Dictionary {
 
     @Override
     public void getBigrams(final WordComposer codes, final CharSequence previousWord,
-            final WordCallback callback, int[] nextLettersFrequencies) {
+            final WordCallback callback) {
         if (!reloadDictionaryIfRequired()) {
             runReverseLookUp(previousWord, callback);
         }
@@ -516,7 +508,7 @@ public class ExpandableDictionary extends Dictionary {
         }
     }
 
-    static char toLowerCase(char c) {
+    private static char toLowerCase(char c) {
         char baseChar = c;
         if (c < BASE_CHARS.length) {
             baseChar = BASE_CHARS[c];
@@ -535,7 +527,7 @@ public class ExpandableDictionary extends Dictionary {
      * if c is not a combined character, or the base character if it
      * is combined.
      */
-    static final char BASE_CHARS[] = {
+    private static final char BASE_CHARS[] = {
         0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 
         0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f, 
         0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index cb1ff41dd..648c1bab8 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -1500,8 +1500,6 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     }
 
     public void updateSuggestions() {
-        mKeyboardSwitcher.setPreferredLetters(null);
-
         // Check if we have a suggestion engine attached.
         if ((mSuggest == null || !isSuggestionsRequested())
                 && !mVoiceConnector.isVoiceInputHighlighted()) {
@@ -1520,7 +1518,6 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     }
 
     private void showCorrections(WordAlternatives alternatives) {
-        mKeyboardSwitcher.setPreferredLetters(null);
         SuggestedWords.Builder builder = alternatives.getAlternatives();
         builder.setTypedWordValid(false).setHasMinimalSuggestion(false);
         showSuggestions(builder.build(), alternatives.getOriginalWord());
@@ -1533,9 +1530,6 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         SuggestedWords.Builder builder = mSuggest.getSuggestedWordBuilder(
                 mKeyboardSwitcher.getInputView(), word, prevWord);
 
-        int[] nextLettersFrequencies = mSuggest.getNextLettersFrequencies();
-        mKeyboardSwitcher.setPreferredLetters(nextLettersFrequencies);
-
         boolean correctionAvailable = !mInputTypeNoAutoCorrect && !mJustReverted
                 && mSuggest.hasAutoCorrection();
         final CharSequence typedWord = word.getTypedWord();
@@ -1704,7 +1698,6 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         saveWordInHistory(suggestion);
         mHasValidSuggestions = false;
         mCommittedLength = suggestion.length();
-        switcher.setPreferredLetters(null);
     }
 
     /**
diff --git a/java/src/com/android/inputmethod/latin/Suggest.java b/java/src/com/android/inputmethod/latin/Suggest.java
index c9e57d0a5..6466f7980 100644
--- a/java/src/com/android/inputmethod/latin/Suggest.java
+++ b/java/src/com/android/inputmethod/latin/Suggest.java
@@ -87,12 +87,6 @@ public class Suggest implements Dictionary.WordCallback {
     private int[] mPriorities = new int[mPrefMaxSuggestions];
     private int[] mBigramPriorities = new int[PREF_MAX_BIGRAMS];
 
-    // Handle predictive correction for only the first 1280 characters for performance reasons
-    // If we support scripts that need latin characters beyond that, we should probably use some
-    // kind of a sparse array or language specific list with a mapping lookup table.
-    // 1280 is the size of the BASE_CHARS array in ExpandableDictionary, which is a basic set of
-    // latin characters.
-    private int[] mNextLettersFrequencies = new int[1280];
     private ArrayList<CharSequence> mSuggestions = new ArrayList<CharSequence>();
     ArrayList<CharSequence> mBigramSuggestions  = new ArrayList<CharSequence>();
     private ArrayList<CharSequence> mStringPool = new ArrayList<CharSequence>();
@@ -216,7 +210,6 @@ public class Suggest implements Dictionary.WordCallback {
         mIsAllUpperCase = wordComposer.isAllUpperCase();
         collectGarbage(mSuggestions, mPrefMaxSuggestions);
         Arrays.fill(mPriorities, 0);
-        Arrays.fill(mNextLettersFrequencies, 0);
 
         // Save a lowercase version of the original word
         CharSequence typedWord = wordComposer.getTypedWord();
@@ -244,16 +237,13 @@ public class Suggest implements Dictionary.WordCallback {
                     prevWordForBigram = lowerPrevWord;
                 }
                 if (mUserBigramDictionary != null) {
-                    mUserBigramDictionary.getBigrams(wordComposer, prevWordForBigram, this,
-                            mNextLettersFrequencies);
+                    mUserBigramDictionary.getBigrams(wordComposer, prevWordForBigram, this);
                 }
                 if (mContactsDictionary != null) {
-                    mContactsDictionary.getBigrams(wordComposer, prevWordForBigram, this,
-                            mNextLettersFrequencies);
+                    mContactsDictionary.getBigrams(wordComposer, prevWordForBigram, this);
                 }
                 if (mMainDict != null) {
-                    mMainDict.getBigrams(wordComposer, prevWordForBigram, this,
-                            mNextLettersFrequencies);
+                    mMainDict.getBigrams(wordComposer, prevWordForBigram, this);
                 }
                 char currentChar = wordComposer.getTypedWord().charAt(0);
                 char currentCharUpper = Character.toUpperCase(currentChar);
@@ -278,10 +268,10 @@ public class Suggest implements Dictionary.WordCallback {
             // At second character typed, search the unigrams (scores being affected by bigrams)
             if (mUserDictionary != null || mContactsDictionary != null) {
                 if (mUserDictionary != null) {
-                    mUserDictionary.getWords(wordComposer, this, mNextLettersFrequencies);
+                    mUserDictionary.getWords(wordComposer, this);
                 }
                 if (mContactsDictionary != null) {
-                    mContactsDictionary.getWords(wordComposer, this, mNextLettersFrequencies);
+                    mContactsDictionary.getWords(wordComposer, this);
                 }
 
                 if (mSuggestions.size() > 0 && isValidWord(typedWord)
@@ -293,7 +283,7 @@ public class Suggest implements Dictionary.WordCallback {
                     mHasAutoCorrection = true;
                 }
             }
-            if (mMainDict != null) mMainDict.getWords(wordComposer, this, mNextLettersFrequencies);
+            if (mMainDict != null) mMainDict.getWords(wordComposer, this);
             if ((mCorrectionMode == CORRECTION_FULL || mCorrectionMode == CORRECTION_FULL_BIGRAM)
                     && mSuggestions.size() > 0 && mPriorities.length > 0) {
                 // TODO: when the normalized score of the first suggestion is nearly equals to
@@ -388,10 +378,6 @@ public class Suggest implements Dictionary.WordCallback {
         }
     }
 
-    public int[] getNextLettersFrequencies() {
-        return mNextLettersFrequencies;
-    }
-
     private void removeDupes() {
         final ArrayList<CharSequence> suggestions = mSuggestions;
         if (suggestions.size() < 2) return;
diff --git a/java/src/com/android/inputmethod/latin/UserDictionary.java b/java/src/com/android/inputmethod/latin/UserDictionary.java
index db5d9244f..c06bd736e 100644
--- a/java/src/com/android/inputmethod/latin/UserDictionary.java
+++ b/java/src/com/android/inputmethod/latin/UserDictionary.java
@@ -126,9 +126,8 @@ public class UserDictionary extends ExpandableDictionary {
     }
 
     @Override
-    public synchronized void getWords(final WordComposer codes, final WordCallback callback,
-            int[] nextLettersFrequencies) {
-        super.getWords(codes, callback, nextLettersFrequencies);
+    public synchronized void getWords(final WordComposer codes, final WordCallback callback) {
+        super.getWords(codes, callback);
     }
 
     @Override
diff --git a/java/src/com/android/inputmethod/latin/WordComposer.java b/java/src/com/android/inputmethod/latin/WordComposer.java
index 2e415b771..e003dcd5b 100644
--- a/java/src/com/android/inputmethod/latin/WordComposer.java
+++ b/java/src/com/android/inputmethod/latin/WordComposer.java
@@ -16,12 +16,16 @@
 
 package com.android.inputmethod.latin;
 
+import com.android.inputmethod.keyboard.KeyDetector;
+
 import java.util.ArrayList;
 
 /**
  * A place to store the currently composing word with information such as adjacent key codes as well
  */
 public class WordComposer {
+    public static final int NOT_A_CODE = KeyDetector.NOT_A_CODE;
+
     /**
      * The list of unicode values for each keystroke (including surrounding keys)
      */