Fix the safety net

Bug: 5453150

Change-Id: I5990feb2622738988bf29843c6bcdb9cbf8bbf33

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

@@ -1722,9 +1722,14 @@ public class LatinIME extends InputMethodServiceCompatWrapper implements Keyboar
     }
 
     public void showSuggestions(SuggestedWords suggestedWords, CharSequence typedWord) {
+        final boolean shouldBlockAutoCorrectionBySafetyNet =
+                Utils.shouldBlockAutoCorrectionBySafetyNet(suggestedWords, mSuggest);
+        if (shouldBlockAutoCorrectionBySafetyNet) {
+            suggestedWords.setShouldBlockAutoCorrection();
+        }
         setSuggestions(suggestedWords);
         if (suggestedWords.size() > 0) {
-            if (Utils.shouldBlockedBySafetyNetForAutoCorrection(suggestedWords, mSuggest)) {
+            if (shouldBlockAutoCorrectionBySafetyNet) {
                 mBestWord = typedWord;
             } else if (suggestedWords.hasAutoCorrectionWord()) {
                 mBestWord = suggestedWords.getWord(1);

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

@@ -29,12 +29,13 @@ public class SuggestedWords {
 
     public final List<CharSequence> mWords;
     public final boolean mTypedWordValid;
-    public final boolean mHasMinimalSuggestion;
+    public final boolean mHasAutoCorrectionCandidate;
     public final boolean mIsPunctuationSuggestions;
     private final List<SuggestedWordInfo> mSuggestedWordInfoList;
+    private boolean mShouldBlockAutoCorrection;
 
     private SuggestedWords(List<CharSequence> words, boolean typedWordValid,
-            boolean hasMinimalSuggestion, boolean isPunctuationSuggestions,
+            boolean hasAutoCorrectionCandidate, boolean isPunctuationSuggestions,
             List<SuggestedWordInfo> suggestedWordInfoList) {
         if (words != null) {
             mWords = words;
@@ -42,9 +43,10 @@ public class SuggestedWords {
             mWords = Collections.emptyList();
         }
         mTypedWordValid = typedWordValid;
-        mHasMinimalSuggestion = hasMinimalSuggestion;
+        mHasAutoCorrectionCandidate = hasAutoCorrectionCandidate;
         mIsPunctuationSuggestions = isPunctuationSuggestions;
         mSuggestedWordInfoList = suggestedWordInfoList;
+        mShouldBlockAutoCorrection = false;
     }
 
     public int size() {
@@ -60,17 +62,25 @@ public class SuggestedWords {
     }
 
     public boolean hasAutoCorrectionWord() {
-        return mHasMinimalSuggestion && size() > 1 && !mTypedWordValid;
+        return mHasAutoCorrectionCandidate && size() > 1 && !mTypedWordValid;
     }
 
     public boolean hasWordAboveAutoCorrectionScoreThreshold() {
-        return mHasMinimalSuggestion && ((size() > 1 && !mTypedWordValid) || mTypedWordValid);
+        return mHasAutoCorrectionCandidate && ((size() > 1 && !mTypedWordValid) || mTypedWordValid);
     }
 
     public boolean isPunctuationSuggestions() {
         return mIsPunctuationSuggestions;
     }
 
+    public void setShouldBlockAutoCorrection() {
+        mShouldBlockAutoCorrection = true;
+    }
+
+    public boolean shouldBlockAutoCorrection() {
+        return mShouldBlockAutoCorrection;
+    }
+
     public static class Builder {
         private List<CharSequence> mWords = new ArrayList<CharSequence>();
         private boolean mTypedWordValid;
@@ -176,6 +186,7 @@ public class SuggestedWords {
             return mWords.get(pos);
         }
 
+        @Override
         public String toString() {
             // Pretty-print method to help debug
             final StringBuilder sb = new StringBuilder("StringBuilder: mTypedWordValid = "

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

@@ -303,6 +303,12 @@ public class SuggestionsView extends RelativeLayout implements OnClickListener,
             } else {
                 color = mColorTypedWord;
             }
+            if (LatinImeLogger.sDBG) {
+                if (index == mCenterSuggestionIndex && suggestions.mHasAutoCorrectionCandidate
+                        && suggestions.shouldBlockAutoCorrection()) {
+                    return 0xFFFF0000;
+                }
+            }
 
             final SuggestedWordInfo info = (pos < suggestions.size())
                     ? suggestions.getInfo(pos) : null;

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

@@ -167,7 +167,9 @@ public class Utils {
         throw new RuntimeException("Can not find input method id for " + packageName);
     }
 
-    public static boolean shouldBlockedBySafetyNetForAutoCorrection(SuggestedWords suggestions,
+    // TODO: Resolve the inconsistencies between the native auto correction algorithms and
+    // this safety net
+    public static boolean shouldBlockAutoCorrectionBySafetyNet(SuggestedWords suggestions,
             Suggest suggest) {
         // Safety net for auto correction.
         // Actually if we hit this safety net, it's actually a bug.
@@ -181,7 +183,8 @@ public class Utils {
         if (typedWord.length() < MINIMUM_SAFETY_NET_CHAR_LENGTH) return false;
         final CharSequence suggestionWord = suggestions.getWord(1);
         final int typedWordLength = typedWord.length();
-        final int maxEditDistanceOfNativeDictionary = typedWordLength < 5 ? 2 : typedWordLength / 2;
+        final int maxEditDistanceOfNativeDictionary =
+                (typedWordLength < 5 ? 2 : typedWordLength / 2) + 1;
         final int distance = Utils.editDistance(typedWord, suggestionWord);
         if (DBG) {
             Log.d(TAG, "Autocorrected edit distance = " + distance
@@ -189,8 +192,8 @@ public class Utils {
         }
         if (distance > maxEditDistanceOfNativeDictionary) {
             if (DBG) {
-                Log.d(TAG, "Safety net: before = " + typedWord + ", after = " + suggestionWord);
+                Log.e(TAG, "Safety net: before = " + typedWord + ", after = " + suggestionWord);
-                Log.w(TAG, "(Error) The edit distance of this correction exceeds limit. "
+                Log.e(TAG, "(Error) The edit distance of this correction exceeds limit. "
                         + "Turning off auto-correction.");
             }
             return true;
@@ -792,6 +795,7 @@ public class Utils {
     }
 
     public static boolean willAutoCorrect(SuggestedWords suggestions) {
-        return !suggestions.mTypedWordValid && suggestions.mHasMinimalSuggestion;
+        return !suggestions.mTypedWordValid && suggestions.mHasAutoCorrectionCandidate
+                && !suggestions.shouldBlockAutoCorrection();
     }
 }