Revert "Next-word suggestion bit in keyboard settings."

This reverts commit 1ae16dc3db170802d1b38273f477125a2a969d32.

Bug 19596067.

Change-Id: Ie7286acbb70b215d7bd08e271bcf14526b68576f

11 files changed, 101 insertions, 15 deletions

diff --git a/java/res/values/config-common.xml b/java/res/values/config-common.xml
index be22cceea..fb20f7c3a 100644
--- a/java/res/values/config-common.xml
+++ b/java/res/values/config-common.xml
@@ -20,6 +20,9 @@
 
 <resources>
     <bool name="config_block_potentially_offensive">true</bool>
+    <!-- Default value for next word prediction: after entering a word and a space only, should we
+         look at input history to suggest a hopefully helpful suggestions for the next word? -->
+    <bool name="config_default_next_word_prediction">true</bool>
 
     <integer name="config_delay_in_milliseconds_to_update_shift_state">100</integer>
     <integer name="config_double_space_period_timeout">1100</integer>
diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index e4b3883af..54579f2d6 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -157,6 +157,11 @@
     <!-- Option to suggest auto correction suggestions very aggressively. Auto-corrects to a word which has even large edit distance from typed word. [CHAR LIMIT=20] -->
     <string name="auto_correction_threshold_mode_very_aggressive">Very aggressive</string>
 
+    <!-- Option to enable using next word suggestions. After the user types a space, with this option on, the keyboard will try to predict the next word. -->
+    <string name="bigram_prediction">Next-word suggestions</string>
+    <!-- Description for "next word suggestion" option. This displays suggestions even when there is no input, based on the previous word. -->
+    <string name="bigram_prediction_summary">Use the previous word in making suggestions</string>
+
     <!-- Option to enable gesture input. The user can input a word by tracing the letters of a word without releasing the finger from the screen. [CHAR LIMIT=30]-->
     <string name="gesture_input">Enable gesture typing</string>
     <!-- Description for "gesture_input" option. The user can input a word by tracing the letters of a word without releasing the finger from the screen. [CHAR LIMIT=65]-->
diff --git a/java/res/xml/prefs_screen_correction.xml b/java/res/xml/prefs_screen_correction.xml
index 284231bf1..a943dc1a3 100644
--- a/java/res/xml/prefs_screen_correction.xml
+++ b/java/res/xml/prefs_screen_correction.xml
@@ -65,4 +65,10 @@
         android:summary="@string/use_contacts_dict_summary"
         android:defaultValue="true"
         android:persistent="true" />
+    <CheckBoxPreference
+        android:key="next_word_prediction"
+        android:title="@string/bigram_prediction"
+        android:summary="@string/bigram_prediction_summary"
+        android:defaultValue="true"
+        android:persistent="true" />
 </PreferenceScreen>
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index 9fab6b413..4ddde1926 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -1530,7 +1530,11 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     // punctuation suggestions (if it's disabled).
     @Override
     public void setNeutralSuggestionStrip() {
-        setSuggestedWords(SuggestedWords.getEmptyInstance());
+        final SettingsValues currentSettings = mSettings.getCurrent();
+        final SuggestedWords neutralSuggestions = currentSettings.mBigramPredictionEnabled
+                ? SuggestedWords.getEmptyInstance()
+                : currentSettings.mSpacingAndPunctuations.mSuggestPuncList;
+        setSuggestedWords(neutralSuggestions);
     }
 
     // TODO: Make this private
diff --git a/java/src/com/android/inputmethod/latin/inputlogic/InputLogic.java b/java/src/com/android/inputmethod/latin/inputlogic/InputLogic.java
index f3840f74e..7e513e5c3 100644
--- a/java/src/com/android/inputmethod/latin/inputlogic/InputLogic.java
+++ b/java/src/com/android/inputmethod/latin/inputlogic/InputLogic.java
@@ -1395,6 +1395,11 @@ public final class InputLogic {
             return;
         }
 
+        if (!mWordComposer.isComposingWord() && !settingsValues.mBigramPredictionEnabled) {
+            mSuggestionStripViewAccessor.setNeutralSuggestionStrip();
+            return;
+        }
+
         final AsyncResultHolder<SuggestedWords> holder = new AsyncResultHolder<>();
         mInputLogicHandler.getSuggestedWords(inputStyle, SuggestedWords.NOT_A_SEQUENCE_NUMBER,
                 new OnGetSuggestedWordsCallback() {
diff --git a/java/src/com/android/inputmethod/latin/settings/CorrectionSettingsFragment.java b/java/src/com/android/inputmethod/latin/settings/CorrectionSettingsFragment.java
index 44c47fdfa..24c39ebc4 100644
--- a/java/src/com/android/inputmethod/latin/settings/CorrectionSettingsFragment.java
+++ b/java/src/com/android/inputmethod/latin/settings/CorrectionSettingsFragment.java
@@ -19,10 +19,12 @@ package com.android.inputmethod.latin.settings;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.os.Build;
 import android.os.Bundle;
+import android.preference.CheckBoxPreference;
 import android.preference.Preference;
 
 import com.android.inputmethod.dictionarypack.DictionarySettingsActivity;
@@ -59,6 +61,8 @@ public final class CorrectionSettingsFragment extends SubScreenFragment {
         final Context context = getActivity();
         final PackageManager pm = context.getPackageManager();
 
+        ensureConsistencyOfAutoCorrectionSettings();
+
         final Preference dictionaryLink = findPreference(Settings.PREF_CONFIGURE_DICTIONARIES_KEY);
         final Intent intent = dictionaryLink.getIntent();
         intent.setClassName(context.getPackageName(), DictionarySettingsActivity.class.getName());
@@ -78,6 +82,19 @@ public final class CorrectionSettingsFragment extends SubScreenFragment {
         }
     }
 
+    @Override
+    public void onSharedPreferenceChanged(final SharedPreferences prefs, final String key) {
+        ensureConsistencyOfAutoCorrectionSettings();
+    }
+
+    private void ensureConsistencyOfAutoCorrectionSettings() {
+        final CheckBoxPreference autoCorrectionPref = (CheckBoxPreference) findPreference(
+                Settings.PREF_AUTO_CORRECTION);
+        if (!autoCorrectionPref.isChecked()) {
+            setPreferenceEnabled(Settings.PREF_BIGRAM_PREDICTIONS, false);
+        }
+    }
+
     private void overwriteUserDictionaryPreference(final Preference userDictionaryPreference) {
         final Activity activity = getActivity();
         final TreeSet<String> localeList = UserDictionaryList.getUserDictionaryLocalesSet(activity);
diff --git a/java/src/com/android/inputmethod/latin/settings/Settings.java b/java/src/com/android/inputmethod/latin/settings/Settings.java
index 6567e7159..715f7bb38 100644
--- a/java/src/com/android/inputmethod/latin/settings/Settings.java
+++ b/java/src/com/android/inputmethod/latin/settings/Settings.java
@@ -83,6 +83,7 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     // TODO: consolidate key preview dismiss delay with the key preview animation parameters.
     public static final String PREF_KEY_PREVIEW_POPUP_DISMISS_DELAY =
             "pref_key_preview_popup_dismiss_delay";
+    public static final String PREF_BIGRAM_PREDICTIONS = "next_word_prediction";
     public static final String PREF_GESTURE_INPUT = "gesture_input";
     public static final String PREF_VIBRATION_DURATION_SETTINGS =
             "pref_vibration_duration_settings";
diff --git a/java/src/com/android/inputmethod/latin/settings/SettingsValues.java b/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
index 3dbbfad9d..112d78639 100644
--- a/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
+++ b/java/src/com/android/inputmethod/latin/settings/SettingsValues.java
@@ -73,6 +73,8 @@ public class SettingsValues {
     public final boolean mUsePersonalizedDicts;
     public final boolean mUseDoubleSpacePeriod;
     public final boolean mBlockPotentiallyOffensive;
+    // Use bigrams to predict the next word when there is no input for it yet
+    public final boolean mBigramPredictionEnabled;
     public final boolean mGestureInputEnabled;
     public final boolean mGestureTrailEnabled;
     public final boolean mGestureFloatingPreviewTextEnabled;
@@ -149,6 +151,7 @@ public class SettingsValues {
         final String autoCorrectionThresholdRawValue = mAutoCorrectEnabled
                 ? res.getString(R.string.auto_correction_threshold_mode_index_modest)
                 : res.getString(R.string.auto_correction_threshold_mode_index_off);
+        mBigramPredictionEnabled = readBigramPredictionEnabled(prefs, res);
         mDoubleSpacePeriodTimeout = res.getInteger(R.integer.config_double_space_period_timeout);
         mHasHardwareKeyboard = Settings.readHasHardwareKeyboard(res.getConfiguration());
         mEnableMetricsLogging = prefs.getBoolean(Settings.PREF_ENABLE_METRICS_LOGGING, true);
@@ -302,6 +305,12 @@ public class SettingsValues {
         return prefs.getBoolean(Settings.PREF_SHOW_SUGGESTIONS, true);
     }
 
+    private static boolean readBigramPredictionEnabled(final SharedPreferences prefs,
+            final Resources res) {
+        return prefs.getBoolean(Settings.PREF_BIGRAM_PREDICTIONS, res.getBoolean(
+                R.bool.config_default_next_word_prediction));
+    }
+
     private static float readAutoCorrectionThreshold(final Resources res,
             final String currentAutoCorrectionSetting) {
         final String[] autoCorrectionThresholdValues = res.getStringArray(
@@ -379,6 +388,8 @@ public class SettingsValues {
         sb.append("" + mUseDoubleSpacePeriod);
         sb.append("\n   mBlockPotentiallyOffensive = ");
         sb.append("" + mBlockPotentiallyOffensive);
+        sb.append("\n   mBigramPredictionEnabled = ");
+        sb.append("" + mBigramPredictionEnabled);
         sb.append("\n   mGestureInputEnabled = ");
         sb.append("" + mGestureInputEnabled);
         sb.append("\n   mGestureTrailEnabled = ");
diff --git a/tests/src/com/android/inputmethod/latin/InputLogicTests.java b/tests/src/com/android/inputmethod/latin/InputLogicTests.java
index e09b1e936..b1b48135f 100644
--- a/tests/src/com/android/inputmethod/latin/InputLogicTests.java
+++ b/tests/src/com/android/inputmethod/latin/InputLogicTests.java
@@ -502,11 +502,9 @@ public class InputLogicTests extends InputTestsBase {
         type(" ");
         sleep(DELAY_TO_WAIT_FOR_PREDICTIONS_MILLIS);
         runMessages();
-        // Corrections have been replaced with predictions.
+        // Test the predictions have been cleared
         SuggestedWords suggestedWords = mLatinIME.getSuggestedWordsForTest();
-        String word = suggestedWords == null ? null : suggestedWords.getWord(0);
-        assertTrue("predictions after double-space-to-period is I or The",
-                "I".equals(word) || "The".equals(word));
+        assertEquals("predictions cleared after double-space-to-period", suggestedWords.size(), 0);
         type(Constants.CODE_DELETE);
         sleep(DELAY_TO_WAIT_FOR_PREDICTIONS_MILLIS);
         runMessages();
@@ -529,6 +527,23 @@ public class InputLogicTests extends InputTestsBase {
                 suggestedWords.size() > 0 ? suggestedWords.getWord(0) : null);
     }
 
+    public void testPredictionsAfterPeriod() {
+        mLatinIME.clearPersonalizedDictionariesForTest();
+        final String WORD_TO_TYPE = "Barack. ";
+        type(WORD_TO_TYPE);
+        sleep(DELAY_TO_WAIT_FOR_PREDICTIONS_MILLIS);
+        runMessages();
+        SuggestedWords suggestedWords = mLatinIME.getSuggestedWordsForTest();
+        assertEquals("No prediction after period after inputting once.", 0, suggestedWords.size());
+
+        type(WORD_TO_TYPE);
+        sleep(DELAY_TO_WAIT_FOR_PREDICTIONS_MILLIS);
+        runMessages();
+        suggestedWords = mLatinIME.getSuggestedWordsForTest();
+        assertEquals("Beginning-of-Sentence prediction after inputting 2 times.", "Barack",
+                suggestedWords.size() > 0 ? suggestedWords.getWord(0) : null);
+    }
+
     public void testPredictionsAfterRecorrection() {
         final String PREFIX = "A ";
         final String WORD_TO_TYPE = "Barack";
diff --git a/tests/src/com/android/inputmethod/latin/InputTestsBase.java b/tests/src/com/android/inputmethod/latin/InputTestsBase.java
index d5e93744a..6ae38c615 100644
--- a/tests/src/com/android/inputmethod/latin/InputTestsBase.java
+++ b/tests/src/com/android/inputmethod/latin/InputTestsBase.java
@@ -78,6 +78,7 @@ public class InputTestsBase extends ServiceTestCase<LatinIMEForTests> {
     protected View mInputView;
     protected InputConnection mInputConnection;
     private boolean mPreviousAutoCorrectSetting;
+    private boolean mPreviousBigramPredictionSettings;
 
     // A helper class to ease span tests
     public static class SpanGetter {
@@ -200,6 +201,8 @@ public class InputTestsBase extends ServiceTestCase<LatinIMEForTests> {
         setupService();
         mLatinIME = getService();
         setDebugMode(true);
+        mPreviousBigramPredictionSettings = setBooleanPreference(Settings.PREF_BIGRAM_PREDICTIONS,
+                true, true /* defaultValue */);
         mPreviousAutoCorrectSetting = setBooleanPreference(Settings.PREF_AUTO_CORRECTION,
                 DEFAULT_AUTO_CORRECTION, DEFAULT_AUTO_CORRECTION);
         mLatinIME.onCreate();
@@ -230,6 +233,8 @@ public class InputTestsBase extends ServiceTestCase<LatinIMEForTests> {
         mLatinIME.onFinishInput();
         runMessages();
         mLatinIME.mHandler.removeAllMessages();
+        setBooleanPreference(Settings.PREF_BIGRAM_PREDICTIONS, mPreviousBigramPredictionSettings,
+                true /* defaultValue */);
         setBooleanPreference(Settings.PREF_AUTO_CORRECTION, mPreviousAutoCorrectSetting,
                 DEFAULT_AUTO_CORRECTION);
         setDebugMode(false);
diff --git a/tests/src/com/android/inputmethod/latin/PunctuationTests.java b/tests/src/com/android/inputmethod/latin/PunctuationTests.java
index 9ac220407..3537918de 100644
--- a/tests/src/com/android/inputmethod/latin/PunctuationTests.java
+++ b/tests/src/com/android/inputmethod/latin/PunctuationTests.java
@@ -19,23 +19,37 @@ package com.android.inputmethod.latin;
 import android.provider.Settings.Secure;
 import android.test.suitebuilder.annotation.LargeTest;
 
+import com.android.inputmethod.latin.R;
+
 @LargeTest
 public class PunctuationTests extends InputTestsBase {
 
+    final String NEXT_WORD_PREDICTION_OPTION = "next_word_prediction";
+
     public void testWordThenSpaceThenPunctuationFromStripTwice() {
         final String WORD_TO_TYPE = "this ";
         final String PUNCTUATION_FROM_STRIP = "!";
         final String EXPECTED_RESULT = "this!! ";
-        mLatinIME.loadSettings();
-        type(WORD_TO_TYPE);
-        sleep(DELAY_TO_WAIT_FOR_UNDERLINE_MILLIS);
-        runMessages();
-        assertTrue("type word then type space should display punctuation strip",
-                mLatinIME.getSuggestedWordsForTest().isPunctuationSuggestions());
-        pickSuggestionManually(PUNCTUATION_FROM_STRIP);
-        pickSuggestionManually(PUNCTUATION_FROM_STRIP);
-        assertEquals("type word then type space then punctuation from strip twice",
-                EXPECTED_RESULT, mEditText.getText().toString());
+        final boolean defaultNextWordPredictionOption =
+                mLatinIME.getResources().getBoolean(R.bool.config_default_next_word_prediction);
+        final boolean previousNextWordPredictionOption =
+                setBooleanPreference(NEXT_WORD_PREDICTION_OPTION, false,
+                        defaultNextWordPredictionOption);
+        try {
+            mLatinIME.loadSettings();
+            type(WORD_TO_TYPE);
+            sleep(DELAY_TO_WAIT_FOR_UNDERLINE_MILLIS);
+            runMessages();
+            assertTrue("type word then type space should display punctuation strip",
+                    mLatinIME.getSuggestedWordsForTest().isPunctuationSuggestions());
+            pickSuggestionManually(PUNCTUATION_FROM_STRIP);
+            pickSuggestionManually(PUNCTUATION_FROM_STRIP);
+            assertEquals("type word then type space then punctuation from strip twice",
+                    EXPECTED_RESULT, mEditText.getText().toString());
+        } finally {
+            setBooleanPreference(NEXT_WORD_PREDICTION_OPTION, previousNextWordPredictionOption,
+                    defaultNextWordPredictionOption);
+        }
     }
 
     public void testWordThenSpaceThenPunctuationFromKeyboardTwice() {