Introduce auto-switch after apostrophes

* For faster typing add a setting that automatically switches
  to letter layout after typing aphostophes.

Signed-off-by: DarkJoker360 <simoespo159@gmail.com>

Author: DarkJoker360

java/res/values/cm_strings.xml

@@ -55,4 +55,8 @@ disposition rather than other common dispositions for Latin languages. [CHAR LIM
     <!-- Preference item for always showing the emoji key -->
     <string name="show_emoji_key">Show emoji key</string>
     <string name="show_emoji_key_summary">Always show emoji key.</string>
+
+    <!-- Preference item for auto-switching back to letters after typing an apostrophe on the symbols keyboard -->
+    <string name="auto_switch_after_apostrophe">Auto-switch after apostrophes</string>
+    <string name="auto_switch_after_apostrophe_summary">Automatically switch back to the letter keyboard after an apostrophe</string>
 </resources>

java/res/xml/prefs_screen_preferences.xml

@@ -54,6 +54,12 @@
         android:summary="@string/use_double_space_period_summary"
         android:defaultValue="true"
         android:persistent="true" />
+    <CheckBoxPreference
+        android:key="pref_auto_switch_after_apostrophe"
+        android:title="@string/auto_switch_after_apostrophe"
+        android:summary="@string/auto_switch_after_apostrophe_summary"
+        android:defaultValue="false"
+        android:persistent="true" />
     <CheckBoxPreference
         android:key="vibrate_on"
         android:title="@string/vibrate_on_keypress"

java/src/com/android/inputmethod/keyboard/KeyboardSwitcher.java

@@ -134,6 +134,7 @@ public void loadKeyboard(final EditorInfo editorInfo, final SettingsValues setti
                 && settingsValues.mIsSplitKeyboardEnabled);
         mKeyboardLayoutSet = builder.build();
         try {
+            mState.setAutoSwitchAfterApostrophe(settingsValues.mAutoSwitchAfterApostrophe);
             mState.onLoadKeyboard(currentAutoCapsState, currentRecapitalizeState);
             mKeyboardTextsSet.setLocale(mRichImm.getCurrentSubtypeLocale(), mThemeContext);
         } catch (KeyboardLayoutSetException e) {

java/src/com/android/inputmethod/keyboard/internal/KeyboardState.java

@@ -89,6 +89,7 @@ public interface SwitchActions {
     private boolean mIsSymbolShifted;
     private boolean mPrevMainKeyboardWasShiftLocked;
     private boolean mPrevSymbolsKeyboardWasShifted;
+    private boolean mAutoSwitchAfterApostrophe;
     private int mRecapitalizeMode;
 
     // For handling double tap.
@@ -125,6 +126,10 @@ public KeyboardState(final SwitchActions switchActions) {
         mRecapitalizeMode = RecapitalizeStatus.NOT_A_RECAPITALIZE_MODE;
     }
 
+    public void setAutoSwitchAfterApostrophe(final boolean enabled) {
+        mAutoSwitchAfterApostrophe = enabled;
+    }
+
     public void onLoadKeyboard(final int autoCapsFlags, final int recapitalizeMode) {
         if (DEBUG_EVENT) {
             Log.d(TAG, "onLoadKeyboard: " + stateToString(autoCapsFlags, recapitalizeMode));
@@ -618,6 +623,10 @@ private static boolean isSpaceOrEnter(final int c) {
         return c == Constants.CODE_SPACE || c == Constants.CODE_ENTER;
     }
 
+    private boolean shouldSwitchBackAfterApostrophe(final int code) {
+        return mAutoSwitchAfterApostrophe && code == Constants.CODE_SINGLE_QUOTE;
+    }
+
     public void onEvent(final Event event, final int autoCapsFlags, final int recapitalizeMode) {
         final int code = event.isFunctionalKeyEvent() ? event.mKeyCode : event.mCodePoint;
         if (DEBUG_EVENT) {
@@ -649,15 +658,18 @@ public void onEvent(final Event event, final int autoCapsFlags, final int recapi
                 // after the user hits an emoji letter followed by an enter or a space.
                 break;
             }
-            if (!isSpaceOrEnter(code) && (Constants.isLetterCode(code)
+            if (shouldSwitchBackAfterApostrophe(code)) {
+                toggleAlphabetAndSymbols(autoCapsFlags, recapitalizeMode);
+                mPrevSymbolsKeyboardWasShifted = false;
+            } else if (!isSpaceOrEnter(code) && (Constants.isLetterCode(code)
                     || code == Constants.CODE_OUTPUT_TEXT)) {
                 mSwitchState = SWITCH_STATE_SYMBOL;
             }
             break;
         case SWITCH_STATE_SYMBOL:
             // Switch back to alpha keyboard mode if user types one or more non-space/enter
-            // characters followed by a space/enter.
-            if (isSpaceOrEnter(code)) {
+            // characters followed by a space/enter or an apostrophe (when enabled).
+            if (isSpaceOrEnter(code) || shouldSwitchBackAfterApostrophe(code)) {
                 toggleAlphabetAndSymbols(autoCapsFlags, recapitalizeMode);
                 mPrevSymbolsKeyboardWasShifted = false;
             }

java/src/com/android/inputmethod/latin/settings/Settings.java

@@ -99,6 +99,8 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     public static final String PREF_ENABLE_METRICS_LOGGING = "pref_enable_metrics_logging";
     public static final String PREF_SHOW_NUMBER_ROW = "pref_show_number_row";
     public static final String PREF_SHOW_NUMBER_ROW_PASSWORD = "pref_show_number_row_password";
+    public static final String PREF_AUTO_SWITCH_AFTER_APOSTROPHE =
+            "pref_auto_switch_after_apostrophe";
 
     public static final String PREF_SHOW_LONGPRESS_HINTS = "pref_show_longpress_hints";
 
@@ -358,6 +360,10 @@ public static boolean readBackspaceTrackpadEnabled(final SharedPreferences prefs
         return prefs.getBoolean(PREF_BACKSPACE_TRACKPAD, true);
     }
 
+    public static boolean readAutoSwitchAfterApostrophe(final SharedPreferences prefs) {
+        return prefs.getBoolean(PREF_AUTO_SWITCH_AFTER_APOSTROPHE, false);
+    }
+
     public static boolean readUseFullscreenMode(final Resources res) {
         return res.getBoolean(R.bool.config_use_fullscreen_mode);
     }

java/src/com/android/inputmethod/latin/settings/SettingsValues.java

@@ -77,6 +77,7 @@ public class SettingsValues {
     public final boolean mBlockPotentiallyOffensive;
     public final boolean mSpaceTrackpadEnabled;
     public final boolean mBackspaceTrackpadEnabled;
+    public final boolean mAutoSwitchAfterApostrophe;
     // Use bigrams to predict the next word when there is no input for it yet
     public final boolean mBigramPredictionEnabled;
     public final boolean mGestureInputEnabled;
@@ -225,6 +226,7 @@ public SettingsValues(final Context context, final SharedPreferences prefs, fina
         }
         mSpaceTrackpadEnabled = Settings.readSpaceTrackpadEnabled(prefs);
         mBackspaceTrackpadEnabled = Settings.readBackspaceTrackpadEnabled(prefs);
+        mAutoSwitchAfterApostrophe = Settings.readAutoSwitchAfterApostrophe(prefs);
     }
 
     public boolean isMetricsLoggingEnabled() {