[Settings] Refactor: Add SystemLocalePickerFragment

Bug: 377664066
Flag: EXEMPT refactor
Change-Id: I79805c639197911d10f3632e50b5feced08c2fd6

res/menu/language_selection_list.xml

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2024 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.
+-->
+
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/locale_search_menu"
+        android:title="@string/locale_search_menu"
+        android:icon="@drawable/ic_search_24dp"
+        android:showAsAction="always|collapseActionView"
+        android:actionViewClass="android.widget.SearchView" />
+
+</menu>

res/values/strings.xml

@@ -402,6 +402,18 @@
     <!-- Category for the app's locale picker activity. [CHAR LIMIT=50]-->
     <string name="all_supported_app_locales_title">All languages</string>
 
+    <!-- Category for suggested locales. [CHAR LIMIT=50]-->
+    <string name="suggested_locales_title">Suggested</string>
+
+    <!-- Category for the locale picker. [CHAR LIMIT=50]-->
+    <string name="all_supported_locales_title">All languages</string>
+
+    <!-- Category for the locale region picker. [CHAR LIMIT=50]-->
+    <string name="all_supported_locales_regions_title">All regions</string>
+
+    <!-- Category for the numbering system of locale region picker. [CHAR LIMIT=50]-->
+    <string name="all_supported_numbering_system_title">All numbering systems</string>
+
     <!-- Title for preference of the system default locale. [CHAR LIMIT=50]-->
     <string name="preference_of_system_locale_title">System language</string>
 
@@ -450,6 +462,15 @@
     <!-- The text of the confirmation dialog for saying this selected locale is unavailable to use. [CHAR LIMIT=NONE]-->
     <string name="desc_unavailable_locale">This language can’t be used as a system language, but you’ve let apps and websites know you prefer this language.</string>
 
+    <!-- Menu item in the locale menu  [CHAR LIMIT=30] -->
+    <string name="locale_search_menu">Search</string>
+    <!-- Title for the language selection screen [CHAR LIMIT=25] -->
+    <string name="language_selection_title">Add a language</string>
+    <!-- Title for the region selection screen [CHAR LIMIT=25] -->
+    <string name="country_selection_title">Region preference</string>
+    <!-- Hint text in a search edit box (used to filter long language / country lists) [CHAR LIMIT=25] -->
+    <string name="search_language_hint">Type language name</string>
+
     <!-- Regional Preferences begin -->
     <!-- The title of the menu entry of regional preferences. [CHAR LIMIT=50] -->
     <string name="regional_preferences_title">Regional preferences</string>

res/xml/system_language_picker.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2024 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"
+    android:title="@string/language_selection_title"
+    android:key="key_system_language_picker_page">
+
+    <PreferenceCategory
+        android:key="system_language_suggested_category"
+        android:title="@string/suggested_locales_title"/>
+
+    <PreferenceCategory
+        android:key="system_language_all_supported_category"
+        android:title="@string/all_supported_locales_title"/>
+
+</PreferenceScreen>

src/com/android/settings/localepicker/SystemLocalePickerFragment.java

@@ -0,0 +1,281 @@
+/**
+ * Copyright (C) 2024 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.localepicker;
+
+import android.app.Activity;
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Filter;
+import android.widget.SearchView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.core.view.ViewCompat;
+import androidx.preference.PreferenceCategory;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.android.internal.app.LocaleHelper;
+import com.android.internal.app.LocaleStore;
+import com.android.internal.app.SystemLocaleCollector;
+import com.android.settings.R;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import com.google.android.material.appbar.AppBarLayout;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.Set;
+
+/**
+ * A locale picker fragment to show system languages.
+ *
+ * <p>It shows suggestions at the top, then the rest of the locales.
+ * Allows the user to search for locales using both their native name and their name in the
+ * default locale.</p>
+ */
+public class SystemLocalePickerFragment extends DashboardFragment implements
+        SearchView.OnQueryTextListener, MenuItem.OnActionExpandListener {
+
+    private static final String TAG = "SystemLocalePickerFragment";
+    private static final String EXTRA_EXPAND_SEARCH_VIEW = "expand_search_view";
+
+    @Nullable private SearchView mSearchView = null;
+    @Nullable private SearchFilter mSearchFilter = null;
+    @Nullable private Set<LocaleStore.LocaleInfo> mLocaleList;
+    @Nullable private List<LocaleStore.LocaleInfo> mLocaleOptions;
+    @Nullable private List<LocaleStore.LocaleInfo> mOriginalLocaleInfos;
+    private AppBarLayout mAppBarLayout;
+    private RecyclerView mRecyclerView;
+    private Activity mActivity;
+    private boolean mExpandSearch;
+
+    @Override
+    public void onCreate(@NonNull Bundle icicle) {
+        super.onCreate(icicle);
+        mActivity = getActivity();
+        if (mActivity.isFinishing()) {
+            return;
+        }
+        setHasOptionsMenu(true);
+
+        mExpandSearch = mActivity.getIntent().getBooleanExtra(EXTRA_EXPAND_SEARCH_VIEW, false);
+        if (icicle != null) {
+            mExpandSearch = icicle.getBoolean(EXTRA_EXPAND_SEARCH_VIEW);
+        }
+
+        SystemLocaleCollector systemLocaleCollector = new SystemLocaleCollector(getContext(), null);
+        mLocaleList = systemLocaleCollector.getSupportedLocaleList(null, false, false);
+        mLocaleOptions = new ArrayList<>(mLocaleList.size());
+    }
+
+    @Override
+    public @NonNull View onCreateView(@NonNull LayoutInflater inflater,
+            @NonNull ViewGroup container, @NonNull Bundle savedInstanceState) {
+        mAppBarLayout = mActivity.findViewById(R.id.app_bar);
+        return super.onCreateView(inflater, container, savedInstanceState);
+    }
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        mRecyclerView = view.findViewById(R.id.recycler_view);
+    }
+
+    @Override
+    public void onSaveInstanceState(@NonNull Bundle outState) {
+        super.onSaveInstanceState(outState);
+        if (mSearchView != null) {
+            outState.putBoolean(EXTRA_EXPAND_SEARCH_VIEW, !mSearchView.isIconified());
+        }
+    }
+
+    @Override
+    public void onCreateOptionsMenu(@NonNull Menu menu, @NonNull MenuInflater inflater) {
+        super.onCreateOptionsMenu(menu, inflater);
+        inflater.inflate(R.menu.language_selection_list, menu);
+        final MenuItem searchMenuItem = menu.findItem(R.id.locale_search_menu);
+        if (searchMenuItem != null) {
+            searchMenuItem.setOnActionExpandListener(this);
+            mSearchView = (SearchView) searchMenuItem.getActionView();
+            mSearchView.setQueryHint(
+                    getContext().getResources().getText(R.string.search_language_hint));
+            mSearchView.setOnQueryTextListener(this);
+            mSearchView.setMaxWidth(Integer.MAX_VALUE);
+            if (mExpandSearch) {
+                searchMenuItem.expandActionView();
+            }
+        }
+    }
+
+    private void filterSearch(@Nullable String query) {
+        if (mSearchFilter == null) {
+            mSearchFilter = new SearchFilter();
+        }
+
+        // TODO: b/30358431 - Add preference of system locales.
+        // mOriginalLocaleInfos = mSystemLocaleAllListPreferenceController.getSupportedLocaleList();
+        // If we haven't load apps list completely, don't filter anything.
+        if (mOriginalLocaleInfos == null) {
+            Log.w(TAG, "Locales haven't loaded completely yet, so nothing can be filtered");
+            return;
+        }
+        mSearchFilter.filter(query);
+    }
+
+    private class SearchFilter extends Filter {
+
+        @Override
+        protected FilterResults performFiltering(CharSequence prefix) {
+            FilterResults results = new FilterResults();
+
+            if (mOriginalLocaleInfos == null) {
+                mOriginalLocaleInfos = new ArrayList<>(mLocaleList);
+            }
+
+            if (TextUtils.isEmpty(prefix)) {
+                results.values = mOriginalLocaleInfos;
+                results.count = mOriginalLocaleInfos.size();
+            } else {
+                // TODO: decide if we should use the string's locale
+                Locale locale = Locale.getDefault();
+                String prefixString = LocaleHelper.normalizeForSearch(prefix.toString(), locale);
+
+                final int count = mOriginalLocaleInfos.size();
+                final ArrayList<LocaleStore.LocaleInfo> newValues = new ArrayList<>();
+
+                for (int i = 0; i < count; i++) {
+                    final LocaleStore.LocaleInfo value = mOriginalLocaleInfos.get(i);
+                    final String nameToCheck = LocaleHelper.normalizeForSearch(
+                            value.getFullNameInUiLanguage(), locale);
+                    final String nativeNameToCheck = LocaleHelper.normalizeForSearch(
+                            value.getFullNameNative(), locale);
+                    if ((wordMatches(nativeNameToCheck, prefixString)
+                            || wordMatches(nameToCheck, prefixString)) && !newValues.contains(
+                            value)) {
+                        newValues.add(value);
+                    }
+                }
+
+                results.values = newValues;
+                results.count = newValues.size();
+            }
+
+            return results;
+        }
+
+        @Override
+        protected void publishResults(CharSequence constraint, FilterResults results) {
+            mLocaleOptions = (ArrayList<LocaleStore.LocaleInfo>) results.values;
+            // Need to scroll to first preference when searching.
+            if (mRecyclerView != null) {
+                mRecyclerView.post(() -> mRecyclerView.scrollToPosition(0));
+            }
+            // TODO: b/30358431 - Add preference of system locales.
+            // mSystemLocaleAllListPreferenceController.onSearchListChanged(mLocaleOptions);
+            // mSuggestedListPreferenceController.onSearchListChanged(mLocaleOptions);
+        }
+
+        // TODO: decide if this is enough, or we want to use a BreakIterator...
+        private boolean wordMatches(String valueText, String prefixString) {
+            if (valueText == null) {
+                return false;
+            }
+
+            // First match against the whole, non-split value
+            if (valueText.startsWith(prefixString)) {
+                return true;
+            }
+
+            return Arrays.stream(valueText.split(" "))
+                    .anyMatch(word -> word.startsWith(prefixString));
+        }
+    }
+
+    @Override
+    public boolean onMenuItemActionExpand(@NonNull MenuItem item) {
+        // To prevent a large space on tool bar.
+        mAppBarLayout.setExpanded(false /*expanded*/, false /*animate*/);
+        // To prevent user can expand the collapsing tool bar view.
+        ViewCompat.setNestedScrollingEnabled(mRecyclerView, false);
+        return true;
+    }
+
+    @Override
+    public boolean onMenuItemActionCollapse(@NonNull MenuItem item) {
+        // We keep the collapsed status after user cancel the search function.
+        mAppBarLayout.setExpanded(false /*expanded*/, false /*animate*/);
+        ViewCompat.setNestedScrollingEnabled(mRecyclerView, true);
+        return true;
+    }
+
+    @Override
+    public boolean onQueryTextSubmit(@Nullable String query) {
+        return false;
+    }
+
+    @Override
+    public boolean onQueryTextChange(@Nullable String newText) {
+        filterSearch(newText);
+        return false;
+    }
+
+    @Override
+    protected String getLogTag() {
+        return TAG;
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        return SettingsEnums.USER_LOCALE_LIST;
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.system_language_picker;
+    }
+
+    @Override
+    protected List<AbstractPreferenceController> createPreferenceControllers(Context context) {
+        return buildPreferenceControllers(context, getSettingsLifecycle());
+    }
+
+    private List<AbstractPreferenceController> buildPreferenceControllers(
+            @NonNull Context context, @Nullable Lifecycle lifecycle) {
+        final List<AbstractPreferenceController> controllers = new ArrayList<>();
+        // TODO: b/30358431 - Add preference of system locales.
+        return controllers;
+    }
+
+    public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
+            new BaseSearchIndexProvider(R.xml.system_language_picker);
+}