[Regional preferences] Add numbering system page.

- Add language selection page
 - Add number format page
 - Refactor some part for readability.

Bug: b/247073388
Bug: b/246929960
Test: atest pass

Change-Id: I617698a3146b6e461467a97de8c08f4c4dc6e7f2

res/values/arrays.xml

@@ -1361,15 +1361,14 @@
     <string-array name="allowlist_hide_summary_in_battery_usage" translatable="false">
     </string-array>
 
-    <!-- A list for all temperature units. [CHAR LIMIT=NONE] -->
+    <!-- A list for all temperature units. [DO NOT TRANSLATE] -->
     <string-array name="temperature_units">
         <item>default</item>
         <item>celsius</item>
-        <item>fahrenheit</item>
+        <item>fahrenhe</item>
-        <item>kelvin</item>
     </string-array>
 
-    <!-- A list for all days of a week. [CHAR LIMIT=NONE] -->
+    <!-- A list for all days of a week. [DO NOT TRANSLATE] -->
     <string-array name="first_day_of_week">
         <item>default</item>
         <item>sun</item>
@@ -1381,7 +1380,7 @@
         <item>sat</item>
     </string-array>
 
-    <!-- A list for all supported calendar types. [CHAR LIMIT=NONE] -->
+    <!-- A list for all supported calendar types. [DO NOT TRANSLATE] -->
     <string-array name="calendar_type">
         <item>default</item>
         <item>chinese</item>

res/values/strings.xml

@@ -360,9 +360,11 @@
     <!-- The summary of the  menu entry of regional preferences. [CHAR LIMIT=NONE] -->
     <string name="regional_preferences_summary">Set units and number preferences</string>
     <!-- The subtitle of main page of regional preferences. [CHAR LIMIT=NONE] -->
-    <string name="regional_preferences_main_page_sub_title">Apps can use your regional preferences to personalize your experience</string>
+    <string name="regional_preferences_main_page_sub_title">Let apps know your regional preferences so they can personalize your experience.</string>
+    <!-- The subtitle of option's page of regional preferences for Temperature units, Calendar and First day of week. [CHAR LIMIT=NONE] -->
+    <string name="regional_preferences_option_page_sub_title">Apps will use your regional preferences where possible.</string>
     <!-- The title of menu entry of Temperature unit preference. [CHAR LIMIT=50] -->
-    <string name="temperature_preferences_title">Temperature</string>
+    <string name="temperature_preferences_title">Temperature units</string>
     <!-- The title of the  menu entry of Calendar type preference. [CHAR LIMIT=50]  -->
     <string name="calendar_preferences_title">Calendar</string>
     <!-- The title of the  menu entry of First day of week preference. [CHAR LIMIT=50]  -->
@@ -370,13 +372,11 @@
     <!-- The title of the menu entry of Numbers system preference. [CHAR LIMIT=50]  -->
     <string name="numbers_preferences_title">Numbers</string>
     <!-- The summary of default string for each regional preference. [CHAR LIMIT=50] -->
-    <string name="default_string_of_regional_preference">[No preference]</string>
+    <string name="default_string_of_regional_preference">Use app default</string>
     <!-- The title of Celsius for preference of temperature unit. [CHAR LIMIT=50] -->
-    <string name="celsius_temperature_unit">Celsius</string>
+    <string name="celsius_temperature_unit">Celsius(\u00B0C)</string>
     <!-- The title of Fahrenheit for preference of temperature unit. [CHAR LIMIT=50] -->
-    <string name="fahrenheit_temperature_unit">Fahrenheit</string>
+    <string name="fahrenheit_temperature_unit">Fahrenheit(\u00B0F)</string>
-    <!-- The title of Kevin for preference of temperature unit. [CHAR LIMIT=50] -->
-    <string name="kevin_temperature_unit">Kevin</string>
     <!-- The title of sunday for preference of first day of week. [CHAR LIMIT=50] -->
     <string name="sunday_first_day_of_week">Sunday</string>
     <!-- The title of monday for preference of first day of week. [CHAR LIMIT=50] -->

res/xml/regional_preference_content_page.xml

@@ -15,4 +15,8 @@
 -->
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <com.android.settingslib.widget.TopIntroPreference
+        android:key="key_option_page_sub_title"
+        android:title="@string/regional_preferences_option_page_sub_title"
+        android:persistent="false" />
 </PreferenceScreen>

res/xml/regional_preference_main_page.xml

@@ -26,24 +26,44 @@
         android:key="key_temperature_unit"
         android:title="@string/temperature_preferences_title"
         android:summary="@string/default_string_of_regional_preference"
-        settings:controller="com.android.settings.regionalpreferences.TemperatureUnitController"/>
+        settings:controller="com.android.settings.regionalpreferences.TemperatureUnitController"
+        settings:fragment="com.android.settings.regionalpreferences.RegionalPreferencesFragment">
+        <extra
+            android:name="arg_key_regional_preference"
+            android:value="mu" />
+    </Preference>
 
     <Preference
         android:key="key_calendar_type"
         android:title="@string/calendar_preferences_title"
         android:summary="@string/default_string_of_regional_preference"
-        settings:controller="com.android.settings.regionalpreferences.CalendarTypeController"/>
+        settings:controller="com.android.settings.regionalpreferences.CalendarTypeController"
+        settings:fragment="com.android.settings.regionalpreferences.RegionalPreferencesFragment">
+        <extra
+            android:name="arg_key_regional_preference"
+            android:value="ca" />
+    </Preference>
 
     <Preference
         android:key="key_first_day_of_week"
         android:title="@string/first_day_of_week_preferences_title"
         android:summary="@string/default_string_of_regional_preference"
-        settings:controller="com.android.settings.regionalpreferences.FirstDayOfWeekController"/>
+        settings:controller="com.android.settings.regionalpreferences.FirstDayOfWeekController"
+        settings:fragment="com.android.settings.regionalpreferences.RegionalPreferencesFragment">
+        <extra
+            android:name="arg_key_regional_preference"
+            android:value="fw" />
+    </Preference>
 
     <Preference
         android:key="key_numbering_system"
         android:title="@string/numbers_preferences_title"
         android:summary="@string/default_string_of_regional_preference"
-        settings:controller="com.android.settings.regionalpreferences.NumberingSystemController"/>
+        settings:controller="com.android.settings.regionalpreferences.NumberingSystemController"
+        settings:fragment="com.android.settings.regionalpreferences.NumberingPreferencesFragment">
+        <extra
+            android:name="arg_key_regional_preference"
+            android:value="arg_value_language_select" />
+    </Preference>
 
 </PreferenceScreen>

res/xml/regional_preference_numbering_system_page.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2023 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" />

src/com/android/settings/regionalpreferences/CalendarTypeController.java

@@ -16,17 +16,10 @@
 
 package com.android.settings.regionalpreferences;
 
-import android.app.settings.SettingsEnums;
 import android.content.Context;
-import android.os.Bundle;
 import android.provider.Settings;
-import android.text.TextUtils;
-import android.util.Log;
-
-import androidx.preference.Preference;
 
 import com.android.settings.core.BasePreferenceController;
-import com.android.settings.core.SubSettingLauncher;
 
 import java.util.Locale;
 
@@ -68,25 +61,7 @@ public class CalendarTypeController extends BasePreferenceController {
             result = LocalePreferences.getCalendarType(false);
         }
 
-        String inputStr = result.isEmpty() ? RegionalPreferencesFragment.TYPE_DEFAULT : result;
+        String inputStr = result.isEmpty() ? RegionalPreferencesDataUtils.DEFAULT_VALUE : result;
         return RegionalPreferencesDataUtils.calendarConverter(mContext, inputStr);
     }
-
-    @Override
-    public boolean handlePreferenceTreeClick(Preference preference) {
-        if (!TextUtils.equals(preference.getKey(), mPreferenceKey)) {
-            Log.e(TAG, "not the key " + preference.getKey() + " / " + mPreferenceKey);
-            return false;
-        }
-
-        final Bundle extra = new Bundle();
-        extra.putString(RegionalPreferencesFragment.TYPE_OF_REGIONAL_PREFERENCE,
-                RegionalPreferencesFragment.TYPE_CALENDAR);
-        new SubSettingLauncher(preference.getContext())
-                .setDestination(RegionalPreferencesFragment.class.getName())
-                .setSourceMetricsCategory(SettingsEnums.REGIONAL_PREFERENCE)
-                .setArguments(extra)
-                .launch();
-        return true;
-    }
 }

src/com/android/settings/regionalpreferences/ExtensionTypes.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import android.annotation.StringDef;
+
+/** Provides necessary value of language tag to Regional Preferences. */
+public class ExtensionTypes {
+
+    public static final String CALENDAR = "ca";
+    public static final String FIRST_DAY_OF_WEEK = "fw";
+    public static final String NUMBERING_SYSTEM = "nu";
+    public static final String TEMPERATURE_UNIT = "mu";
+
+    @StringDef({
+            FIRST_DAY_OF_WEEK,
+            CALENDAR,
+            TEMPERATURE_UNIT,
+            NUMBERING_SYSTEM
+    })
+    public @interface Values {}
+}

src/com/android/settings/regionalpreferences/FirstDayOfWeekController.java

@@ -16,18 +16,11 @@
 
 package com.android.settings.regionalpreferences;
 
-import android.app.settings.SettingsEnums;
 import android.content.Context;
-import android.os.Bundle;
 import android.provider.Settings;
-import android.text.TextUtils;
-import android.util.Log;
-
-import androidx.preference.Preference;
 
 import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
-import com.android.settings.core.SubSettingLauncher;
 
 import java.util.Locale;
 
@@ -71,22 +64,4 @@ public class FirstDayOfWeekController extends BasePreferenceController {
                 ? mContext.getString(R.string.default_string_of_regional_preference)
                 : RegionalPreferencesDataUtils.dayConverter(mContext, result);
     }
-
-    @Override
-    public boolean handlePreferenceTreeClick(Preference preference) {
-        if (!TextUtils.equals(preference.getKey(), mPreferenceKey)) {
-            Log.e(TAG, "not the key " + preference.getKey() + " / " + mPreferenceKey);
-            return false;
-        }
-
-        final Bundle extra = new Bundle();
-        extra.putString(RegionalPreferencesFragment.TYPE_OF_REGIONAL_PREFERENCE,
-                RegionalPreferencesFragment.TYPE_FIRST_DAY_OF_WEEK);
-        new SubSettingLauncher(preference.getContext())
-                .setDestination(RegionalPreferencesFragment.class.getName())
-                .setSourceMetricsCategory(SettingsEnums.REGIONAL_PREFERENCE)
-                .setArguments(extra)
-                .launch();
-        return true;
-    }
 }

src/com/android/settings/regionalpreferences/LocalePreferences.java

@@ -276,7 +276,7 @@ public final class LocalePreferences {
         /** Celsius */
         public static final String CELSIUS = "celsius";
         /** Fahrenheit */
-        public static final String FAHRENHEIT = "fahrenheit";
+        public static final String FAHRENHEIT = "fahrenhe";
         /** Kelvin */
         public static final String KELVIN = "kelvin";
         /** Default Temperature for the locale */
@@ -301,7 +301,7 @@ public final class LocalePreferences {
     /**
      * Return the user's preference of the temperature unit which is from {@link
      * Locale#getDefault(Locale.Category)}. The returned result is resolved and bases on the
-     * {@code Locale#getDefault(Locale.Category)} settings. E.g. "fahrenheit"
+     * {@code Locale#getDefault(Locale.Category)} settings. E.g. "fahrenhe"
      */
     @NonNull
     @OptIn(markerClass = BuildCompat.PrereleaseSdkCheck.class)
@@ -312,7 +312,7 @@ public final class LocalePreferences {
 
     /**
      * Return the temperature unit of the inputted {@link Locale}. The returned result is resolved
-     * and bases on the inputted {@code Locale} settings. E.g. "fahrenheit"
+     * and bases on the inputted {@code Locale} settings. E.g. "fahrenhe"
      */
     @NonNull
     @OptIn(markerClass = BuildCompat.PrereleaseSdkCheck.class)
@@ -324,7 +324,7 @@ public final class LocalePreferences {
 
     /**
      * Return the user's preference of the temperature unit which is from {@link
-     * Locale#getDefault(Locale.Category)}. E.g. "fahrenheit"
+     * Locale#getDefault(Locale.Category)}. E.g. "fahrenhe"
      *
      * @param resolved If the {@code Locale#getDefault(Locale.Category)} contains temperature unit
      *                 subtag, this argument is ignored. If the
@@ -522,9 +522,6 @@ public final class LocalePreferences {
             String mu =
                     locale.getUnicodeLocaleType(TemperatureUnit.U_EXTENSION_OF_TEMPERATURE_UNIT);
             if (mu != null) {
-                if (mu.contains("fahrenhe")) {
-                    mu = TemperatureUnit.FAHRENHEIT;
-                }
                 return mu;
             }
             if (!resolved) {
@@ -592,7 +589,11 @@ public final class LocalePreferences {
                     .usage("temperature")
                     .unit(MeasureUnit.CELSIUS)
                     .locale(locale);
-            return nf.format(1).getOutputUnit().getIdentifier();
+            String unit = nf.format(1).getOutputUnit().getIdentifier();
+            if (unit.contains(TemperatureUnit.FAHRENHEIT)) {
+                return TemperatureUnit.FAHRENHEIT;
+            }
+            return unit;
         }
 
         private Api33Impl() {

src/com/android/settings/regionalpreferences/NumberingPreferencesFragment.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.os.Bundle;
+import android.util.Log;
+
+import androidx.annotation.VisibleForTesting;
+
+import com.android.settings.R;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settingslib.core.AbstractPreferenceController;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+/** Provides options of numbering system to each language. */
+public class NumberingPreferencesFragment  extends DashboardFragment {
+    /** Initializes variables. */
+    @VisibleForTesting
+    String initTitle() {
+        String option = getArguments().getString(
+                RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE, "");
+        if (option.isEmpty()) {
+            Log.d(getLogTag(), "Option is empty.");
+            return "";
+        }
+        Log.i(getLogTag(), "[NumberingPreferencesFragment] option is " + option);
+
+        if (option.equals(NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT)) {
+            return getContext().getString(R.string.numbers_preferences_title);
+        } else if (option.equals(NumberingSystemItemController.ARG_VALUE_NUMBERING_SYSTEM_SELECT)) {
+            String selectedLanguage = getArguments().getString(
+                    NumberingSystemItemController.KEY_SELECTED_LANGUAGE, "");
+            if (selectedLanguage.isEmpty()) {
+                Log.w(getLogTag(), "No selected language.");
+                return "";
+            }
+            return Locale.forLanguageTag(selectedLanguage)
+                    .stripExtensions()
+                    .getDisplayName(Locale.forLanguageTag(selectedLanguage));
+        }
+        Log.w(getLogTag(), "Incorrect option : " + option);
+        return "";
+    }
+
+    @Override
+    public void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+        String title = initTitle();
+        if (initTitle().isEmpty()) {
+            finish();
+        } else {
+            getActivity().setTitle(title);
+        }
+    }
+
+    /**
+     * Get a list of {@link AbstractPreferenceController} for this fragment.
+     */
+    @Override
+    protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
+        NumberingSystemItemController controller =
+                new NumberingSystemItemController(context, getArguments());
+        controller.setParentFragment(this);
+        List<AbstractPreferenceController> listControllers = new ArrayList<>();
+        listControllers.add(controller);
+        return listControllers;
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.regional_preference_numbering_system_page;
+    }
+
+    /**
+     * Get the tag string for logging.
+     */
+    @Override
+    protected String getLogTag() {
+        return NumberingPreferencesFragment.class.getSimpleName();
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        String option = getArguments().getString(
+                RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE, "");
+        if (option.equals(NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT)) {
+            return SettingsEnums.NUMBERING_SYSTEM_LANGUAGE_SELECTION_PREFERENCE;
+        } else {
+            return SettingsEnums.NUMBERING_SYSTEM_NUMBER_FORMAT_SELECTION_PREFERENCE;
+        }
+    }
+}

src/com/android/settings/regionalpreferences/NumberingSystemController.java

@@ -16,28 +16,18 @@
 
 package com.android.settings.regionalpreferences;
 
-import android.app.settings.SettingsEnums;
 import android.content.Context;
-import android.icu.text.NumberingSystem;
+import android.os.LocaleList;
-import android.os.Bundle;
-import android.provider.Settings;
-import android.text.TextUtils;
-import android.util.Log;
 
-import androidx.preference.Preference;
-
-import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
-import com.android.settings.core.SubSettingLauncher;
 
 import java.util.Locale;
+import java.util.StringJoiner;
 
 /** A controller for the entry of Numbering System's page */
 public class NumberingSystemController extends BasePreferenceController {
     private static final String TAG = NumberingSystemController.class.getSimpleName();
 
-    private static final String UNICODE_EXTENSION_NUMBERING_SYSTEM = "nu";
-
     public NumberingSystemController(Context context, String preferenceKey) {
         super(context, preferenceKey);
     }
@@ -55,49 +45,17 @@ public class NumberingSystemController extends BasePreferenceController {
      */
     @Override
     public int getAvailabilityStatus() {
-        // Hide this , and waiting for next implementation.
+        return AVAILABLE;
-        return CONDITIONALLY_UNAVAILABLE;
     }
 
     @Override
     public CharSequence getSummary() {
-        String record = Settings.System.getString(
+        LocaleList localeList = LocaleList.getDefault();
-                mContext.getContentResolver(), Settings.System.LOCALE_PREFERENCES);
+        StringJoiner stringJoiner = new StringJoiner(", ");
-        String result = "";
+        for (int i = 0; i < localeList.size(); i++) {
-        if (!TextUtils.isEmpty(record)) {
+            Locale locale = localeList.get(i);
-            result = Locale.forLanguageTag(record)
+            stringJoiner.add(locale.stripExtensions().getDisplayName(locale));
-                    .getUnicodeLocaleType(UNICODE_EXTENSION_NUMBERING_SYSTEM);
         }
-
+        return stringJoiner.toString();
-        if (TextUtils.isEmpty(result)) {
-            result = Locale.getDefault(Locale.Category.FORMAT)
-                    .getUnicodeLocaleType(UNICODE_EXTENSION_NUMBERING_SYSTEM);
-            if (TextUtils.isEmpty(result)) {
-                return mContext.getString(R.string.default_string_of_regional_preference);
-            }
-        }
-
-        Locale locale = new Locale.Builder()
-                .setUnicodeLocaleKeyword(UNICODE_EXTENSION_NUMBERING_SYSTEM, result)
-                .build();
-        return NumberingSystem.getInstance(locale).getName();
-    }
-
-    @Override
-    public boolean handlePreferenceTreeClick(Preference preference) {
-        if (!TextUtils.equals(preference.getKey(), mPreferenceKey)) {
-            Log.e(TAG, "not the key " + preference.getKey() + " / " + mPreferenceKey);
-            return false;
-        }
-
-        final Bundle extra = new Bundle();
-        extra.putString(RegionalPreferencesFragment.TYPE_OF_REGIONAL_PREFERENCE,
-                RegionalPreferencesFragment.TYPE_NUMBERING_SYSTEM);
-        new SubSettingLauncher(preference.getContext())
-                .setDestination(RegionalPreferencesFragment.class.getName())
-                .setSourceMetricsCategory(SettingsEnums.REGIONAL_PREFERENCE)
-                .setArguments(extra)
-                .launch();
-        return true;
     }
 }

src/com/android/settings/regionalpreferences/NumberingSystemItemController.java

@@ -0,0 +1,216 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.icu.text.NumberingSystem;
+import android.icu.util.ULocale;
+import android.os.Bundle;
+import android.os.LocaleList;
+import android.text.TextUtils;
+import android.util.Log;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+import com.android.internal.app.LocaleHelper;
+import com.android.internal.app.LocalePicker;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settings.core.SubSettingLauncher;
+import com.android.settings.dashboard.DashboardFragment;
+
+import java.util.Locale;
+
+/** Uses to control the preference UI of numbering system page. */
+public class NumberingSystemItemController extends BasePreferenceController {
+    private static final String TAG = NumberingSystemItemController.class.getSimpleName();
+
+    static final String ARG_VALUE_NUMBERING_SYSTEM_SELECT = "arg_value_numbering_system_select";
+    static final String ARG_VALUE_LANGUAGE_SELECT = "arg_value_language_select";
+    static final String KEY_SELECTED_LANGUAGE = "key_selected_language";
+    private static final String DISPLAY_KEYWORD_NUMBERING_SYSTEM = "numbers";
+
+    private String mOption = "";
+    private String mSelectedLanguage = "";
+    private DashboardFragment mParentFragment;
+    private PreferenceScreen mPreferenceScreen;
+
+    public NumberingSystemItemController(Context context, Bundle argument) {
+        super(context, "no_key");
+        mOption = argument.getString(
+                RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE, "");
+        mSelectedLanguage = argument.getString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE, "");
+    }
+
+    /**
+     * Displays preference in this controller.
+     */
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreferenceScreen = screen;
+        if (mOption.equals(ARG_VALUE_LANGUAGE_SELECT)) {
+            initLanguageOptionsUi(screen);
+        } else if (mOption.equals(ARG_VALUE_NUMBERING_SYSTEM_SELECT)) {
+            initNumberingSystemOptionsUi(screen, Locale.forLanguageTag(mSelectedLanguage));
+        }
+    }
+
+    /**
+     * Sets the parent fragment and attaches this controller to the settings lifecycle.
+     *
+     * @param fragment the fragment to use as the parent
+     */
+    public void setParentFragment(DashboardFragment fragment) {
+        mParentFragment = fragment;
+    }
+
+    /**
+     * @return {@link AvailabilityStatus} for the Setting. This status is used to determine if the
+     * Setting should be shown or disabled in Settings. Further, it can be used to produce
+     * appropriate error / warning Slice in the case of unavailability.
+     * </p>
+     * The status is used for the convenience methods: {@link #isAvailable()}, {@link
+     * #isSupported()}
+     * </p>
+     * The inherited class doesn't need to check work profile if android:forWork="true" is set in
+     * preference xml.
+     */
+    @Override
+    public int getAvailabilityStatus() {
+        return AVAILABLE;
+    }
+
+    @Override
+    public boolean handlePreferenceTreeClick(Preference preference) {
+        if (mOption.equals(ARG_VALUE_LANGUAGE_SELECT)) {
+            handleLanguageSelect(preference);
+        } else if (mOption.equals(ARG_VALUE_NUMBERING_SYSTEM_SELECT)) {
+            handleNumberSystemSelect(preference);
+        }
+        return true;
+    }
+
+    private void initLanguageOptionsUi(PreferenceScreen screen) {
+        // Get current system language list to show on screen.
+        LocaleList localeList = LocaleList.getDefault();
+        for (int i = 0; i < localeList.size(); i++) {
+            Preference pref = new Preference(mContext);
+            Locale locale = localeList.get(i);
+            pref.setTitle(LocaleHelper.getDisplayName(locale.stripExtensions(), locale, true));
+            pref.setKey(locale.toLanguageTag());
+            pref.setSummary(getNumberingSystem(locale));
+            screen.addPreference(pref);
+        }
+    }
+
+    private void initNumberingSystemOptionsUi(PreferenceScreen screen, Locale targetLocale) {
+        String[] locales = LocalePicker.getSupportedLocales(mContext);
+        for (String localeTag : locales) {
+            Locale supportedLocale = Locale.forLanguageTag(localeTag);
+            if (isSameBaseLocale(targetLocale, supportedLocale)) {
+                TickButtonPreference pref = new TickButtonPreference(mContext);
+                String numberingName = getNumberingSystem(supportedLocale);
+                pref.setTitle(numberingName);
+                String key = supportedLocale.getUnicodeLocaleType(
+                        ExtensionTypes.NUMBERING_SYSTEM);
+                pref.setKey(key == null ? RegionalPreferencesDataUtils.DEFAULT_VALUE : key);
+                pref.setTickEnable(isSameNumberingSystem(targetLocale, supportedLocale));
+                screen.addPreference(pref);
+            }
+        }
+    }
+
+    private void handleLanguageSelect(Preference preference) {
+        final Bundle extra = new Bundle();
+        extra.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+        extra.putString(KEY_SELECTED_LANGUAGE, preference.getKey());
+        new SubSettingLauncher(preference.getContext())
+                .setDestination(NumberingPreferencesFragment.class.getName())
+                .setSourceMetricsCategory(
+                        SettingsEnums.NUMBERING_SYSTEM_LANGUAGE_SELECTION_PREFERENCE)
+                .setArguments(extra)
+                .launch();
+    }
+
+    private void handleNumberSystemSelect(Preference preference) {
+        for (int i = 0; i < mPreferenceScreen.getPreferenceCount(); i++) {
+            TickButtonPreference pref = (TickButtonPreference) mPreferenceScreen.getPreference(i);
+            Log.i(TAG, "[onPreferenceClick] key is " + pref.getKey());
+            if (pref.getKey().equals(preference.getKey())) {
+                pref.setTickEnable(true);
+                Locale updatedLocale =
+                        saveNumberingSystemToLocale(
+                                Locale.forLanguageTag(mSelectedLanguage), pref.getKey());
+
+                // After updated locale to framework, this fragment will recreate,
+                // so it need to update the argement of selected language.
+                Bundle bundle = new Bundle();
+                bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                        ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+                bundle.putString(KEY_SELECTED_LANGUAGE, updatedLocale.toLanguageTag());
+                mParentFragment.setArguments(bundle);
+                continue;
+            }
+            pref.setTickEnable(false);
+        }
+    }
+
+    private Locale saveNumberingSystemToLocale(Locale targetLocale, String value) {
+        LocaleList localeList = LocalePicker.getLocales();
+        Locale[] locales = new Locale[localeList.size()];
+        for (int i = 0; i < localeList.size(); i++) {
+            Locale locale = localeList.get(i);
+            if (targetLocale.equals(locale)) {
+                if (value.equals(RegionalPreferencesDataUtils.DEFAULT_VALUE)) {
+                    value = null;
+                }
+                Locale updatedLocale = new Locale.Builder()
+                        .setLocale(locale)
+                        .setUnicodeLocaleKeyword(ExtensionTypes.NUMBERING_SYSTEM, value)
+                        .build();
+                locales[i] = updatedLocale;
+                continue;
+            }
+            locales[i] = localeList.get(i);
+        }
+        LocalePicker.updateLocales(new LocaleList(locales));
+        return targetLocale;
+    }
+
+    private static String getNumberingSystem(Locale locale) {
+        ULocale uLocale = new ULocale.Builder()
+                .setUnicodeLocaleKeyword(ExtensionTypes.NUMBERING_SYSTEM,
+                        NumberingSystem.getInstance(locale).getName())
+                .build();
+        return uLocale.getDisplayKeywordValue(DISPLAY_KEYWORD_NUMBERING_SYSTEM,
+                ULocale.forLocale(locale));
+    }
+
+    private static boolean isSameNumberingSystem(Locale locale1, Locale locale2) {
+        String name1 = NumberingSystem.getInstance(locale1).getName();
+        String name2 = NumberingSystem.getInstance(locale2).getName();
+        return TextUtils.equals(name1, name2);
+    }
+
+    private static boolean isSameBaseLocale(Locale locale1, Locale locale2) {
+        return locale1.stripExtensions().equals(locale2.stripExtensions());
+    }
+}

src/com/android/settings/regionalpreferences/RegionalPreferencesDataUtils.java

@@ -29,10 +29,8 @@ import java.util.Locale;
 
 /** Provides utils for regional preferences. */
 public class RegionalPreferencesDataUtils {
-    private static final String TAG = RegionalPreferencesDataUtils.class.getSimpleName();
+    static final String DISPLAY_KEYWORD_OF_CALENDAR = "calendar";
-
+    static final String DEFAULT_VALUE = "default";
-    private static final String U_EXTENSION_FAHRENHEIT = "fahrenhe";
-    private static final String KEYWORD_OF_CALENDAR = "calendar";
 
     static String getDefaultUnicodeExtensionData(Context contxt, String type) {
         // 1. Check cache data in Settings provider.
@@ -47,27 +45,11 @@ public class RegionalPreferencesDataUtils {
         if (TextUtils.isEmpty(result)) {
             result = Locale.getDefault(Locale.Category.FORMAT).getUnicodeLocaleType(type);
         }
-        if (result == null) {
-            return RegionalPreferencesFragment.TYPE_DEFAULT;
-        }
 
-        // In BCP47 expression, the tag of fahrenheit is "fahrenhe" i.e. und-u-mu-fahrenhe,
+        return result == null ? DEFAULT_VALUE : result;
-        // so if it may need to convert from the langngiage tag, "fahrenhe", to "fahrenheit".
-        if (result.equals(U_EXTENSION_FAHRENHEIT)) {
-            return LocalePreferences.TemperatureUnit.FAHRENHEIT;
-        }
-
-        return result;
     }
 
     static void savePreference(Context context, String type, String value) {
-        if (type.equals(RegionalPreferencesFragment.TYPE_TEMPERATURE)
-                && value != null && value.equals(LocalePreferences.TemperatureUnit.FAHRENHEIT)) {
-            // In BCP47 expression, the temperature unit is expressed to "fahrenhe"
-            // i.e. zh-TW-u-mu-fahrenhe. Hence, if we want to save fahrenheit unit to u extension,
-            // It need to change from "fahrenheit" to "fahrenhe".
-            value = U_EXTENSION_FAHRENHEIT;
-        }
         saveToSettingsProvider(context, type, value);
         saveToSystem(type, value);
     }
@@ -105,14 +87,14 @@ public class RegionalPreferencesDataUtils {
     }
 
     static String calendarConverter(Context context, String calendarType) {
-        if (calendarType.equals(RegionalPreferencesFragment.TYPE_DEFAULT)) {
+        if (calendarType.equals(DEFAULT_VALUE)) {
             return context.getString(R.string.default_string_of_regional_preference);
         }
 
         Locale locale = new Locale.Builder()
-                .setUnicodeLocaleKeyword(RegionalPreferencesFragment.TYPE_CALENDAR, calendarType)
+                .setUnicodeLocaleKeyword(ExtensionTypes.CALENDAR, calendarType)
                 .build();
-        return ULocale.getDisplayKeywordValue(locale.toLanguageTag(), KEYWORD_OF_CALENDAR,
+        return ULocale.getDisplayKeywordValue(locale.toLanguageTag(), DISPLAY_KEYWORD_OF_CALENDAR,
                 ULocale.forLocale(Locale.getDefault(Locale.Category.FORMAT)));
     }
 
@@ -122,8 +104,6 @@ public class RegionalPreferencesDataUtils {
                 return context.getString(R.string.celsius_temperature_unit);
             case LocalePreferences.TemperatureUnit.FAHRENHEIT:
                 return context.getString(R.string.fahrenheit_temperature_unit);
-            case LocalePreferences.TemperatureUnit.KELVIN:
-                return context.getString(R.string.kevin_temperature_unit);
             default:
                 return context.getString(R.string.default_string_of_regional_preference);
         }

src/com/android/settings/regionalpreferences/RegionalPreferencesEntriesFragment.java

@@ -28,6 +28,8 @@ import com.android.settingslib.search.SearchIndexable;
 public class RegionalPreferencesEntriesFragment extends DashboardFragment {
     private static final String TAG = RegionalPreferencesEntriesFragment.class.getSimpleName();
 
+    static final String ARG_KEY_REGIONAL_PREFERENCE = "arg_key_regional_preference";
+
     @Override
     public void onStart() {
         super.onStart();

src/com/android/settings/regionalpreferences/RegionalPreferencesFragment.java

@@ -34,13 +34,6 @@ import com.android.settings.SettingsPreferenceFragment;
 public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
     private static final String TAG = RegionalPreferencesFragment.class.getSimpleName();
 
-    static final String TYPE_DEFAULT = "default";
-    static final String TYPE_TEMPERATURE = "mu";
-    static final String TYPE_CALENDAR = "ca";
-    static final String TYPE_FIRST_DAY_OF_WEEK = "fw";
-    static final String TYPE_NUMBERING_SYSTEM = "nu";
-    static final String TYPE_OF_REGIONAL_PREFERENCE = "type_of_regional_preference";
-
     private PreferenceScreen mPreferenceScreen;
     private String mTitle = "";
     @VisibleForTesting
@@ -48,18 +41,15 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
 
     private String[] initializeUIdata(String type) {
         switch(type) {
-            case TYPE_TEMPERATURE:
+            case ExtensionTypes.TEMPERATURE_UNIT:
                 mTitle = getPrefContext().getString(R.string.temperature_preferences_title);
                 return getPrefContext().getResources().getStringArray(R.array.temperature_units);
-            case TYPE_CALENDAR:
+            case ExtensionTypes.CALENDAR:
                 mTitle = getPrefContext().getString(R.string.calendar_preferences_title);
                 return getPrefContext().getResources().getStringArray(R.array.calendar_type);
-            case TYPE_FIRST_DAY_OF_WEEK:
+            case ExtensionTypes.FIRST_DAY_OF_WEEK:
                 mTitle = getPrefContext().getString(R.string.first_day_of_week_preferences_title);
                 return getPrefContext().getResources().getStringArray(R.array.first_day_of_week);
-            case TYPE_NUMBERING_SYSTEM:
-                mTitle = getPrefContext().getString(R.string.numbers_preferences_title);
-                return new String[0];
             default:
                 mTitle = getPrefContext().getString(R.string.regional_preferences_title);
                 return new String[0];
@@ -68,7 +58,8 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
 
     @Override
     public boolean onPreferenceTreeClick(Preference preference) {
-        for (int i = 0; i < mPreferenceScreen.getPreferenceCount(); i++) {
+        // The first preference is TopIntroPreference
+        for (int i = 1; i < mPreferenceScreen.getPreferenceCount(); i++) {
             TickButtonPreference pref = (TickButtonPreference) mPreferenceScreen.getPreference(i);
             Log.i(TAG, "[onPreferenceClick] key is " + pref.getKey());
             if (pref.getKey().equals(preference.getKey())) {
@@ -76,7 +67,9 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
                 RegionalPreferencesDataUtils.savePreference(
                         getPrefContext(),
                         mType,
-                        preference.getKey().equals(TYPE_DEFAULT) ? null : preference.getKey());
+                        preference.getKey().equals(
+                                RegionalPreferencesDataUtils.DEFAULT_VALUE)
+                                ? null : preference.getKey());
                 continue;
             }
             pref.setTickEnable(false);
@@ -88,7 +81,8 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);
         Bundle bundle = getArguments();
-        String type = bundle.getString(TYPE_OF_REGIONAL_PREFERENCE, "");
+        String type = bundle.getString(
+                RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE, "");
         if (type.isEmpty()) {
             Log.w(TAG, "There is no type name.");
             finish();
@@ -101,18 +95,16 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
-        View view = super.onCreateView(inflater, container, savedInstanceState);
         String[] uiData = initializeUIdata(mType);
-
         for (String item : uiData) {
             TickButtonPreference pref = new TickButtonPreference(getPrefContext());
-            if (mType.equals(TYPE_FIRST_DAY_OF_WEEK)) {
+            if (mType.equals(ExtensionTypes.FIRST_DAY_OF_WEEK)) {
                 pref.setTitle(RegionalPreferencesDataUtils.dayConverter(
                         getPrefContext(), item));
-            } else if (mType.equals(TYPE_TEMPERATURE)) {
+            } else if (mType.equals(ExtensionTypes.TEMPERATURE_UNIT)) {
                 pref.setTitle(RegionalPreferencesDataUtils.temperatureUnitsConverter(
                         getPrefContext(), item));
-            } else if (mType.equals(TYPE_CALENDAR)) {
+            } else if (mType.equals(ExtensionTypes.CALENDAR)) {
                 pref.setTitle(RegionalPreferencesDataUtils.calendarConverter(
                         getPrefContext(), item));
             } else {
@@ -126,7 +118,7 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
             pref.setTickEnable(!value.isEmpty() && item.equals(value));
             mPreferenceScreen.addPreference(pref);
         }
-        return view;
+        return super.onCreateView(inflater, container, savedInstanceState);
     }
 
     @Override
@@ -138,9 +130,9 @@ public class RegionalPreferencesFragment extends SettingsPreferenceFragment {
     @Override
     public int getMetricsCategory() {
         switch(mType) {
-            case TYPE_CALENDAR:
+            case ExtensionTypes.CALENDAR:
                 return SettingsEnums.CALENDAR_PREFERENCE;
-            case TYPE_FIRST_DAY_OF_WEEK:
+            case ExtensionTypes.FIRST_DAY_OF_WEEK:
                 return SettingsEnums.FIRST_DAY_OF_WEEK_PREFERENCE;
             default:
                 return SettingsEnums.TEMPERATURE_PREFERENCE;

src/com/android/settings/regionalpreferences/TemperatureUnitController.java

@@ -16,18 +16,11 @@
 
 package com.android.settings.regionalpreferences;
 
-import android.app.settings.SettingsEnums;
 import android.content.Context;
-import android.os.Bundle;
 import android.provider.Settings;
-import android.text.TextUtils;
-import android.util.Log;
-
-import androidx.preference.Preference;
 
 import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
-import com.android.settings.core.SubSettingLauncher;
 
 import java.util.Locale;
 
@@ -71,21 +64,4 @@ public class TemperatureUnitController extends BasePreferenceController {
                 ? mContext.getString(R.string.default_string_of_regional_preference)
                 : RegionalPreferencesDataUtils.temperatureUnitsConverter(mContext, result);
     }
-
-    @Override
-    public boolean handlePreferenceTreeClick(Preference preference) {
-        if (!TextUtils.equals(preference.getKey(), mPreferenceKey)) {
-            Log.e(TAG, "not the key " + preference.getKey() + " / " + mPreferenceKey);
-            return false;
-        }
-        final Bundle extra = new Bundle();
-        extra.putString(RegionalPreferencesFragment.TYPE_OF_REGIONAL_PREFERENCE,
-                RegionalPreferencesFragment.TYPE_TEMPERATURE);
-        new SubSettingLauncher(preference.getContext())
-                .setDestination(RegionalPreferencesFragment.class.getName())
-                .setSourceMetricsCategory(SettingsEnums.REGIONAL_PREFERENCE)
-                .setArguments(extra)
-                .launch();
-        return true;
-    }
 }

tests/unit/src/com/android/settings/regionalpreferences/CalendarTypeControllerTest.java

@@ -98,8 +98,10 @@ public class CalendarTypeControllerTest {
     private static String getDisplayKeywordValue(String value) {
         String languageTag = new Locale.Builder()
                 .setUnicodeLocaleKeyword(
-                        RegionalPreferencesFragment.TYPE_CALENDAR, value).build().toLanguageTag();
+                        ExtensionTypes.CALENDAR, value).build().toLanguageTag();
-        return ULocale.getDisplayKeywordValue(languageTag, "calendar",
+        return ULocale.getDisplayKeywordValue(
+                languageTag,
+                RegionalPreferencesDataUtils.DISPLAY_KEYWORD_OF_CALENDAR,
                 ULocale.forLocale(Locale.getDefault(Locale.Category.FORMAT)));
     }
 }

tests/unit/src/com/android/settings/regionalpreferences/NumberingPreferencesFragmentTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import static org.junit.Assert.assertEquals;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.os.Bundle;
+import android.os.Looper;
+
+import androidx.test.annotation.UiThreadTest;
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.settings.testutils.ResourcesUtils;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Locale;
+
+public class NumberingPreferencesFragmentTest {
+    private Context mApplicationContext;
+    private NumberingPreferencesFragment mFragment;
+
+    @Before
+    @UiThreadTest
+    public void setUp() throws Exception {
+        if (Looper.myLooper() == null) {
+            Looper.prepare();
+        }
+        mApplicationContext = ApplicationProvider.getApplicationContext();
+        mFragment = new NumberingPreferencesFragment();
+    }
+
+    @Test
+    @UiThreadTest
+    public void initTitle_optionIsLanguageSelection_titleIsNumbers() {
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT);
+        mFragment.setArguments(bundle);
+
+        String result = mFragment.initTitle();
+
+        assertEquals(ResourcesUtils.getResourcesString(
+                mApplicationContext, "numbers_preferences_title"), result);
+    }
+
+    @Test
+    @UiThreadTest
+    public void initTitle_optionIsNumberingSystemSelection_titleIsLocaleDisplayName() {
+        Locale expectedLocale = Locale.forLanguageTag("en-US");
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+        bundle.putString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE,
+                expectedLocale.toLanguageTag());
+        mFragment.setArguments(bundle);
+
+        String result = mFragment.initTitle();
+
+        assertEquals(expectedLocale.getDisplayName(expectedLocale), result);
+    }
+
+    @Test
+    @UiThreadTest
+    public void getMetricsCategory_optionIsLanguageSelection_resultIsLanguageSelection() {
+        Bundle extras = new Bundle();
+        extras.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT);
+        mFragment.setArguments(extras);
+
+        int result = mFragment.getMetricsCategory();
+
+        assertEquals(SettingsEnums.NUMBERING_SYSTEM_LANGUAGE_SELECTION_PREFERENCE, result);
+    }
+
+    @Test
+    @UiThreadTest
+    public void getMetricsCategory_optionIsNumberSelection_resultIsNumberSelection() {
+        Bundle extras = new Bundle();
+        extras.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+        mFragment.setArguments(extras);
+
+        int result = mFragment.getMetricsCategory();
+
+        assertEquals(SettingsEnums.NUMBERING_SYSTEM_NUMBER_FORMAT_SELECTION_PREFERENCE, result);
+    }
+}

tests/unit/src/com/android/settings/regionalpreferences/NumberingSystemControllerTest.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import static org.junit.Assert.assertEquals;
+
+import android.content.Context;
+import android.os.LocaleList;
+
+import androidx.test.core.app.ApplicationProvider;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Locale;
+
+public class NumberingSystemControllerTest {
+    private Context mApplicationContext;
+    private NumberingSystemController mController;
+    private LocaleList mCacheLocales;
+
+    @Before
+    public void setUp() throws Exception {
+        mApplicationContext = ApplicationProvider.getApplicationContext();
+        mController = new NumberingSystemController(mApplicationContext, "key");
+        mCacheLocales = LocaleList.getDefault();
+    }
+
+
+    @After
+    public void tearDown() throws Exception {
+        LocaleList.setDefault(mCacheLocales);
+    }
+
+    @Test
+    public void getSummary_has1Locale_showEnUs() {
+        LocaleList.setDefault(LocaleList.forLanguageTags("en-US"));
+
+        String summary = mController.getSummary().toString();
+
+        String expectedResult =
+                Locale.forLanguageTag("en-us").getDisplayName();
+        assertEquals(expectedResult, summary);
+    }
+
+    @Test
+    public void getSummary_has2Locales_showEnUsAndZhTw() {
+        LocaleList.setDefault(LocaleList.forLanguageTags("en-US,zh-TW"));
+
+        String summary = mController.getSummary().toString();
+
+        Locale locale1 = Locale.forLanguageTag("en-US");
+        Locale locale2 = Locale.forLanguageTag("zh-TW");
+        String expectedResult =
+                locale1.getDisplayName(locale1) + ", " + locale2.getDisplayName(locale2);
+        assertEquals(expectedResult, summary);
+    }
+
+    @Test
+    public void getSummary_localeHasExtensionTag_showEnUsWithoutTag() {
+        LocaleList.setDefault(LocaleList.forLanguageTags("en-US-u-ca-chinese"));
+
+        String summary = mController.getSummary().toString();
+
+        String expectedResult = Locale.forLanguageTag("en-US").getDisplayName();
+        assertEquals(expectedResult, summary);
+    }
+}

tests/unit/src/com/android/settings/regionalpreferences/NumberingSystemItemControllerTest.java

@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.regionalpreferences;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.os.LocaleList;
+import android.os.Looper;
+import android.util.AndroidRuntimeException;
+
+import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
+import androidx.test.annotation.UiThreadTest;
+import androidx.test.core.app.ApplicationProvider;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Locale;
+
+public class NumberingSystemItemControllerTest {
+    private Context mApplicationContext;
+    private NumberingSystemItemController mController;
+    private NumberingPreferencesFragment mFragment;
+    private PreferenceScreen mPreferenceScreen;
+    private LocaleList mCacheLocale;
+
+    @Before
+    @UiThreadTest
+    public void setUp() throws Exception {
+        if (Looper.myLooper() == null) {
+            Looper.prepare();
+        }
+        mApplicationContext = ApplicationProvider.getApplicationContext();
+        mFragment = spy(new NumberingPreferencesFragment());
+        PreferenceManager preferenceManager = new PreferenceManager(mApplicationContext);
+        mPreferenceScreen = preferenceManager.createPreferenceScreen(mApplicationContext);
+        mCacheLocale = LocaleList.getDefault();
+    }
+
+    @After
+    public void tearDown() {
+        LocaleList.setDefault(mCacheLocale);
+    }
+
+    @Test
+    @UiThreadTest
+    public void handlePreferenceTreeClick_languageSelect_launchFragment() {
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT);
+        bundle.putString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE, Locale.US.toLanguageTag());
+        TickButtonPreference preference = new TickButtonPreference(mApplicationContext);
+        preference.setKey("I_am_the_key");
+        mPreferenceScreen.addPreference(preference);
+        mController = new NumberingSystemItemController(mApplicationContext, bundle);
+        mController.setParentFragment(mFragment);
+        mController.displayPreference(mPreferenceScreen);
+
+        boolean isCallingStartActivity = false;
+        try {
+            mController.handlePreferenceTreeClick(preference);
+        } catch (AndroidRuntimeException exception) {
+            isCallingStartActivity = true;
+        }
+
+        assertTrue(isCallingStartActivity);
+    }
+
+    @Test
+    @UiThreadTest
+    public void handlePreferenceTreeClick_numbersSelect_preferenceHasTick() {
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+        bundle.putString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE, Locale.US.toLanguageTag());
+        TickButtonPreference preference = new TickButtonPreference(mApplicationContext);
+        preference.setKey("test_key");
+        mPreferenceScreen.addPreference(preference);
+        mController = new NumberingSystemItemController(mApplicationContext, bundle);
+        mController.setParentFragment(mFragment);
+        mController.displayPreference(mPreferenceScreen);
+
+        mController.handlePreferenceTreeClick(preference);
+
+        verify(mFragment).setArguments(any());
+    }
+
+    @Test
+    @UiThreadTest
+    public void displayPreference_languageOptAndHas2Locale_show2Options() {
+        LocaleList.setDefault(LocaleList.forLanguageTags("en-US, zh-TW"));
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_LANGUAGE_SELECT);
+        bundle.putString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE, Locale.US.toLanguageTag());
+        mController = new NumberingSystemItemController(mApplicationContext, bundle);
+        mController.setParentFragment(mFragment);
+
+        mController.displayPreference(mPreferenceScreen);
+
+        assertEquals(LocaleList.getDefault().size(), mPreferenceScreen.getPreferenceCount());
+    }
+
+    @Test
+    @UiThreadTest
+    public void displayPreference_enUsNumbersOpt_show1Option() {
+        LocaleList.setDefault(LocaleList.forLanguageTags("en-US, zh-TW"));
+        Bundle bundle = new Bundle();
+        bundle.putString(RegionalPreferencesEntriesFragment.ARG_KEY_REGIONAL_PREFERENCE,
+                NumberingSystemItemController.ARG_VALUE_NUMBERING_SYSTEM_SELECT);
+        bundle.putString(
+                NumberingSystemItemController.KEY_SELECTED_LANGUAGE, Locale.US.toLanguageTag());
+        mController = new NumberingSystemItemController(mApplicationContext, bundle);
+        mController.setParentFragment(mFragment);
+
+        mController.displayPreference(mPreferenceScreen);
+
+        // en-US only has 1 numbering system.
+        assertEquals(1, mPreferenceScreen.getPreferenceCount());
+    }
+}

tests/unit/src/com/android/settings/regionalpreferences/RegionalPreferencesDataUtilsTest.java

@@ -62,7 +62,7 @@ public class RegionalPreferencesDataUtilsTest {
                 mApplicationContext, "und-u-mu-celsius");
 
         String unit = RegionalPreferencesDataUtils.getDefaultUnicodeExtensionData(
-                mApplicationContext, RegionalPreferencesFragment.TYPE_TEMPERATURE);
+                mApplicationContext, ExtensionTypes.TEMPERATURE_UNIT);
 
         assertEquals(LocalePreferences.TemperatureUnit.CELSIUS, unit);
     }
@@ -74,7 +74,7 @@ public class RegionalPreferencesDataUtilsTest {
         Locale.setDefault(Locale.forLanguageTag("en-US-u-mu-celsius"));
 
         String unit = RegionalPreferencesDataUtils.getDefaultUnicodeExtensionData(
-                mApplicationContext, RegionalPreferencesFragment.TYPE_TEMPERATURE);
+                mApplicationContext, ExtensionTypes.TEMPERATURE_UNIT);
 
         assertEquals(LocalePreferences.TemperatureUnit.CELSIUS, unit);
     }
@@ -86,16 +86,16 @@ public class RegionalPreferencesDataUtilsTest {
         Locale.setDefault(Locale.forLanguageTag("en-US"));
 
         String unit = RegionalPreferencesDataUtils.getDefaultUnicodeExtensionData(
-                mApplicationContext, RegionalPreferencesFragment.TYPE_TEMPERATURE);
+                mApplicationContext, ExtensionTypes.TEMPERATURE_UNIT);
 
-        assertEquals(RegionalPreferencesFragment.TYPE_DEFAULT, unit);
+        assertEquals(RegionalPreferencesDataUtils.DEFAULT_VALUE, unit);
     }
 
     @Test
     public void savePreference_saveCalendarIsDangi_success() {
         RegionalPreferencesDataUtils.savePreference(
                 mApplicationContext,
-                RegionalPreferencesFragment.TYPE_CALENDAR,
+                ExtensionTypes.CALENDAR,
                 LocalePreferences.CalendarType.DANGI
         );
         String providerContent = Settings.System.getString(
@@ -103,12 +103,12 @@ public class RegionalPreferencesDataUtilsTest {
         Locale locale = Locale.forLanguageTag(providerContent);
 
 
-        String result1 = locale.getUnicodeLocaleType(RegionalPreferencesFragment.TYPE_CALENDAR);
+        String result1 = locale.getUnicodeLocaleType(ExtensionTypes.CALENDAR);
 
         assertEquals(LocalePreferences.CalendarType.DANGI, result1);
 
         String result2 = Locale.getDefault(Locale.Category.FORMAT)
-                .getUnicodeLocaleType(RegionalPreferencesFragment.TYPE_CALENDAR);
+                .getUnicodeLocaleType(ExtensionTypes.CALENDAR);
 
         assertEquals(LocalePreferences.CalendarType.DANGI, result2);
 
@@ -126,7 +126,7 @@ public class RegionalPreferencesDataUtilsTest {
     @Test
     public void temperatureUnitsConverter_inputDefault_resultIsDefaultString() {
         String result = RegionalPreferencesDataUtils.temperatureUnitsConverter(mApplicationContext,
-                RegionalPreferencesFragment.TYPE_DEFAULT);
+                RegionalPreferencesDataUtils.DEFAULT_VALUE);
 
         assertEquals(ResourcesUtils.getResourcesString(
                 mApplicationContext, "default_string_of_regional_preference"), result);
@@ -144,7 +144,7 @@ public class RegionalPreferencesDataUtilsTest {
     @Test
     public void dayConverter_inputDefault_resultIsDefaultString() {
         String result = RegionalPreferencesDataUtils.dayConverter(mApplicationContext,
-                RegionalPreferencesFragment.TYPE_DEFAULT);
+                RegionalPreferencesDataUtils.DEFAULT_VALUE);
 
         assertEquals(ResourcesUtils.getResourcesString(
                 mApplicationContext, "default_string_of_regional_preference"), result);
@@ -153,7 +153,7 @@ public class RegionalPreferencesDataUtilsTest {
     @Test
     public void calendarConverter_inputDefault_resultIsDefaultString() {
         String result = RegionalPreferencesDataUtils.dayConverter(mApplicationContext,
-                RegionalPreferencesFragment.TYPE_DEFAULT);
+                RegionalPreferencesDataUtils.DEFAULT_VALUE);
 
         assertEquals(ResourcesUtils.getResourcesString(
                 mApplicationContext, "default_string_of_regional_preference"), result);

tests/unit/src/com/android/settings/regionalpreferences/RegionalPreferencesFragmentTest.java

@@ -41,7 +41,7 @@ public class RegionalPreferencesFragmentTest {
     @Test
     @UiThreadTest
     public void getMetricsCategory_typeIsCa_resultIsCalendarPreference() {
-        mFragment.mType = RegionalPreferencesFragment.TYPE_CALENDAR;
+        mFragment.mType = ExtensionTypes.CALENDAR;
 
         int result = mFragment.getMetricsCategory();
 
@@ -51,7 +51,7 @@ public class RegionalPreferencesFragmentTest {
     @Test
     @UiThreadTest
     public void getMetricsCategory_typeIsFw_resultIsFirstDayOfWeekPreference() {
-        mFragment.mType = RegionalPreferencesFragment.TYPE_FIRST_DAY_OF_WEEK;
+        mFragment.mType = ExtensionTypes.FIRST_DAY_OF_WEEK;
 
         int result = mFragment.getMetricsCategory();
 
@@ -61,7 +61,7 @@ public class RegionalPreferencesFragmentTest {
     @Test
     @UiThreadTest
     public void getMetricsCategory_typeIsMu_resultIsTemperaturePreference() {
-        mFragment.mType = RegionalPreferencesFragment.TYPE_TEMPERATURE;
+        mFragment.mType = ExtensionTypes.TEMPERATURE_UNIT;
 
         int result = mFragment.getMetricsCategory();