Move mBestWord to the word composer.

mBestWord has a confusing name - it's actually an auto-correction.
It's cleaner if it lives in the word composer because an
auto-correction should be tied to a specific user input, and
should be reset each time the user input changes to avoid
race conditions.

Change-Id: I718d29395bc747372067e6440e090c6a181994ae

java/src/com/android/inputmethod/latin/LatinIME.java

@@ -203,7 +203,6 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
     private boolean mApplicationSpecifiedCompletionOn;
 
     private WordComposer mWordComposer = new WordComposer();
-    private CharSequence mBestWord;
     private boolean mHasUncommittedTypedChars;
 
     private int mCorrectionMode;
@@ -1019,7 +1018,7 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
                     .setHasMinimalSuggestion(false);
             // When in fullscreen mode, show completions generated by the application
             setSuggestions(builder.build());
-            mBestWord = null;
+            mWordComposer.deleteAutoCorrection();
             setSuggestionStripShown(true);
         }
     }
@@ -1649,10 +1648,18 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
         Utils.Stats.onSeparator((char)primaryCode, x, y);
 
         if (pickedDefault) {
-            CharSequence typedWord = mWordComposer.getTypedWord();
-            if (!TextUtils.isEmpty(typedWord) && !typedWord.equals(mBestWord)) {
+            final CharSequence autoCorrection = mWordComposer.getAutoCorrectionOrNull();
+            final String typedWord = mWordComposer.getTypedWord();
+            if (TextUtils.isEmpty(typedWord)) {
+                throw new RuntimeException("We have non-committed chars but the typed word "
+                        + "is empty? Impossible! I must commit suicide.");
+            }
+            if (!typedWord.equals(autoCorrection)) {
+                // TODO: if the commitCorrection method is not supported by the platform
+                // this will do nothing and the correction will not be committed at all. What
+                // happens on Froyo/Gingerbread, where this API is not present?
                 InputConnectionCompatUtils.commitCorrection(
-                        ic, mLastSelectionEnd - typedWord.length(), typedWord, mBestWord);
+                        ic, mLastSelectionEnd - typedWord.length(), typedWord, autoCorrection);
             }
         }
         mKeyboardSwitcher.updateShiftState();
@@ -1847,14 +1854,15 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
         setSuggestions(suggestedWords);
         if (suggestedWords.size() > 0) {
             if (shouldBlockAutoCorrectionBySafetyNet) {
-                mBestWord = typedWord;
+                mWordComposer.setAutoCorrection(typedWord);
             } else if (suggestedWords.hasAutoCorrectionWord()) {
-                mBestWord = suggestedWords.getWord(1);
+                mWordComposer.setAutoCorrection(suggestedWords.getWord(1));
             } else {
-                mBestWord = typedWord;
+                mWordComposer.setAutoCorrection(typedWord);
             }
         } else {
-            mBestWord = null;
+            // TODO: replace with mWordComposer.deleteAutoCorrection()?
+            mWordComposer.setAutoCorrection(null);
         }
         setSuggestionStripShown(isSuggestionsStripVisible());
     }
@@ -1865,16 +1873,17 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
             mHandler.cancelUpdateSuggestions();
             updateSuggestions();
         }
-        if (mBestWord != null && mBestWord.length() > 0) {
-            Utils.Stats.onAutoCorrection(mWordComposer.getTypedWord(), mBestWord.toString(),
-                    separatorCode);
+        final CharSequence autoCorrection = mWordComposer.getAutoCorrectionOrNull();
+        if (autoCorrection != null) {
+            final String typedWord = mWordComposer.getTypedWord();
+            Utils.Stats.onAutoCorrection(typedWord, autoCorrection.toString(), separatorCode);
             mExpectingUpdateSelection = true;
-            commitBestWord(mBestWord);
-            if (!mBestWord.equals(mWordComposer.getTypedWord())) {
-                mWordSavedForAutoCorrectCancellation = mBestWord.toString();
+            commitBestWord(autoCorrection);
+            if (!autoCorrection.equals(typedWord)) {
+                mWordSavedForAutoCorrectCancellation = autoCorrection.toString();
             }
             // Add the word to the user unigram dictionary if it's not a known word
-            addToUserUnigramAndBigramDictionaries(mBestWord,
+            addToUserUnigramAndBigramDictionaries(autoCorrection,
                     UserUnigramDictionary.FREQUENCY_FOR_TYPED);
             return true;
         }
@@ -2153,8 +2162,6 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
     private void restartSuggestionsOnWordBeforeCursor(final InputConnection ic,
             final CharSequence word) {
         mWordComposer.setComposingWord(word, mKeyboardSwitcher.getLatinKeyboard());
-        // mBestWord will be set appropriately by updateSuggestions() called by the handler
-        mBestWord = null;
         mHasUncommittedTypedChars = true;
         mComposingStateManager.onStartComposingText();
         ic.deleteSurroundingText(word.length(), 0);

java/src/com/android/inputmethod/latin/WordComposer.java

@@ -41,6 +41,8 @@ public class WordComposer {
     private int[] mYCoordinates;
 
     private StringBuilder mTypedWord;
+    // An auto-correction for this word out of the dictionary.
+    private CharSequence mAutoCorrection;
 
     private int mCapsCount;
 
@@ -60,6 +62,7 @@ public class WordComposer {
         mXCoordinates = new int[N];
         mYCoordinates = new int[N];
         mTrailingSingleQuotesCount = 0;
+        mAutoCorrection = null;
     }
 
     public WordComposer(WordComposer source) {
@@ -75,6 +78,7 @@ public class WordComposer {
         mIsFirstCharCapitalized = source.mIsFirstCharCapitalized;
         mAutoCapitalized = source.mAutoCapitalized;
         mTrailingSingleQuotesCount = source.mTrailingSingleQuotesCount;
+        mAutoCorrection = null;
     }
 
     /**
@@ -86,6 +90,7 @@ public class WordComposer {
         mCapsCount = 0;
         mIsFirstCharCapitalized = false;
         mTrailingSingleQuotesCount = 0;
+        mAutoCorrection = null;
     }
 
     /**
@@ -140,6 +145,7 @@ public class WordComposer {
         } else {
             mTrailingSingleQuotesCount = 0;
         }
+        mAutoCorrection = null;
     }
 
     /**
@@ -173,6 +179,7 @@ public class WordComposer {
             int codePoint = word.charAt(i);
             addKeyInfo(codePoint, keyboard, keyDetector);
         }
+        mAutoCorrection = null;
     }
 
     /**
@@ -224,11 +231,12 @@ public class WordComposer {
                 ++mTrailingSingleQuotesCount;
             }
         }
+        mAutoCorrection = null;
     }
 
     /**
      * Returns the word as it was typed, without any correction applied.
-     * @return the word that was typed so far
+     * @return the word that was typed so far. Never returns null.
      */
     public String getTypedWord() {
         return mTypedWord.toString();
@@ -277,4 +285,25 @@ public class WordComposer {
     public boolean isAutoCapitalized() {
         return mAutoCapitalized;
     }
+
+    /**
+     * Sets the auto-correction for this word.
+     */
+    public void setAutoCorrection(final CharSequence correction) {
+        mAutoCorrection = correction;
+    }
+
+    /**
+     * Remove any auto-correction that may have been set.
+     */
+    public void deleteAutoCorrection() {
+        mAutoCorrection = null;
+    }
+
+    /**
+     * @return the auto-correction for this world, or null if none.
+     */
+    public CharSequence getAutoCorrectionOrNull() {
+        return mAutoCorrection;
+    }
 }