Enable "show language switch key" settings on K and before

"Show language switch key" and "Switch to other IME" settings are
enabled on KitKat and before. On L and later, its preference settings
UI gets hide and the settings values are forcibly set to true.

Bug: 14854377
Change-Id: I10456408452280a1b7688fd1f168933937666c9f

java/res/xml/prefs.xml

@@ -153,6 +153,7 @@
                 android:defaultValue="true" />
             <CheckBoxPreference
                 android:key="pref_include_other_imes_in_language_switch_list"
+                android:dependency="pref_show_language_switch_key"
                 android:title="@string/include_other_imes_in_language_switch_list"
                 android:summary="@string/include_other_imes_in_language_switch_list_summary"
                 android:persistent="true"

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

@@ -20,6 +20,7 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.pm.ApplicationInfo;
 import android.content.res.Resources;
+import android.os.Build;
 import android.preference.PreferenceManager;
 import android.util.Log;
 
@@ -60,6 +61,10 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
             "pref_key_use_double_space_period";
     public static final String PREF_BLOCK_POTENTIALLY_OFFENSIVE =
             "pref_key_block_potentially_offensive";
+    public static final boolean ENABLE_SHOW_LANGUAGE_SWITCH_KEY_SETTINGS =
+            (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT)
+            || (Build.VERSION.SDK_INT == Build.VERSION_CODES.KITKAT
+                    && Build.VERSION.CODENAME.equals("REL"));
     public static final String PREF_SHOW_LANGUAGE_SWITCH_KEY =
             "pref_show_language_switch_key";
     public static final String PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST =

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

@@ -59,7 +59,7 @@ public final class SettingsFragment extends InputMethodSettingsFragment
     private static final boolean DBG_USE_INTERNAL_PERSONAL_DICTIONARY_SETTINGS = false;
     private static final boolean USE_INTERNAL_PERSONAL_DICTIONARY_SETTIGS =
             DBG_USE_INTERNAL_PERSONAL_DICTIONARY_SETTINGS
-                    || Build.VERSION.SDK_INT <= 18 /* Build.VERSION.JELLY_BEAN_MR2 */;
+            || Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN_MR2;
 
     private void setPreferenceEnabled(final String preferenceKey, final boolean enabled) {
         final Preference preference = findPreference(preferenceKey);
@@ -169,6 +169,13 @@ public final class SettingsFragment extends InputMethodSettingsFragment
             removePreference(Settings.PREF_VIBRATE_ON, generalSettings);
             removePreference(Settings.PREF_VIBRATION_DURATION_SETTINGS, advancedSettings);
         }
+        if (!Settings.ENABLE_SHOW_LANGUAGE_SWITCH_KEY_SETTINGS) {
+            removePreference(
+                    Settings.PREF_SHOW_LANGUAGE_SWITCH_KEY, advancedSettings);
+            removePreference(
+                    Settings.PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST, advancedSettings);
+        }
+
 
         // TODO: consolidate key preview dismiss delay with the key preview animation parameters.
         if (!Settings.readFromBuildConfigIfToShowKeyPreviewPopupOption(res)) {
@@ -199,9 +206,6 @@ public final class SettingsFragment extends InputMethodSettingsFragment
             removePreference(Settings.PREF_SHOW_SETUP_WIZARD_ICON, advancedSettings);
         }
 
-        setPreferenceEnabled(Settings.PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST,
-                Settings.readShowsLanguageSwitchKey(prefs));
-
         final PreferenceGroup textCorrectionGroup =
                 (PreferenceGroup) findPreference(Settings.PREF_CORRECTION_SETTINGS);
         final PreferenceScreen dictionaryLink =
@@ -299,9 +303,6 @@ public final class SettingsFragment extends InputMethodSettingsFragment
         if (key.equals(Settings.PREF_POPUP_ON)) {
             setPreferenceEnabled(Settings.PREF_KEY_PREVIEW_POPUP_DISMISS_DELAY,
                     Settings.readKeyPreviewPopupEnabled(prefs, res));
-        } else if (key.equals(Settings.PREF_SHOW_LANGUAGE_SWITCH_KEY)) {
-            setPreferenceEnabled(Settings.PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST,
-                    Settings.readShowsLanguageSwitchKey(prefs));
         } else if (key.equals(Settings.PREF_SHOW_SETUP_WIZARD_ICON)) {
             LauncherIconVisibilityManager.updateSetupWizardIconVisibility(getActivity());
         }

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

@@ -125,9 +125,11 @@ public final class SettingsValues {
         final String autoCorrectionThresholdRawValue = prefs.getString(
                 Settings.PREF_AUTO_CORRECTION_THRESHOLD,
                 res.getString(R.string.auto_correction_threshold_mode_index_modest));
-        mIncludesOtherImesInLanguageSwitchList = prefs.getBoolean(
+        mIncludesOtherImesInLanguageSwitchList = Settings.ENABLE_SHOW_LANGUAGE_SWITCH_KEY_SETTINGS
-                Settings.PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST, false);
+                ? prefs.getBoolean(Settings.PREF_INCLUDE_OTHER_IMES_IN_LANGUAGE_SWITCH_LIST, false)
-        mShowsLanguageSwitchKey = Settings.readShowsLanguageSwitchKey(prefs);
+                : true /* forcibly */;
+        mShowsLanguageSwitchKey = Settings.ENABLE_SHOW_LANGUAGE_SWITCH_KEY_SETTINGS
+                ? Settings.readShowsLanguageSwitchKey(prefs) : true /* forcibly */;
         mUseContactsDict = prefs.getBoolean(Settings.PREF_KEY_USE_CONTACTS_DICT, true);
         mUsePersonalizedDicts = prefs.getBoolean(Settings.PREF_KEY_USE_PERSONALIZED_DICTS, true);
         mUseDoubleSpacePeriod = prefs.getBoolean(Settings.PREF_KEY_USE_DOUBLE_SPACE_PERIOD, true);
@@ -171,7 +173,7 @@ public final class SettingsValues {
                 ResourceUtils.getFloatFromFraction(
                         res, R.fraction.config_key_preview_dismiss_end_scale));
         mDisplayOrientation = res.getConfiguration().orientation;
-        mAppWorkarounds = new AsyncResultHolder<AppWorkaroundsUtils>();
+        mAppWorkarounds = new AsyncResultHolder<>();
         final PackageInfo packageInfo = TargetPackageInfoGetterTask.getCachedPackageInfo(
                 mInputAttributes.mTargetApplicationPackageName);
         if (null != packageInfo) {