[Android] Add utilities for Clank language decouple

This second of four CLs to enable Clank to be in a seperate
locale from the system.

This CL adds the Android preference key APPLICATION_OVERRIDE_LANGUAGE
that will be used to store the override language for Clank.

It also adds utility functions and tests for managing the language
preference and modifying Configuration locales.

Bug: 1068667
Change-Id: Ia8aa6d55c6373696b8af12be43c8741d29bf38d1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2355489
Commit-Queue: Trevor  Perrier <perrier@chromium.org>
Reviewed-by: Brandon Wylie <wylieb@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802894}

base/android/java/src/org/chromium/base/LocaleUtils.java

@@ -5,13 +5,17 @@
 package org.chromium.base;
 
 import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.res.Configuration;
 import android.os.Build;
 import android.os.LocaleList;
 import android.text.TextUtils;
 
+import androidx.annotation.RequiresApi;
 import androidx.annotation.VisibleForTesting;
 
 import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.VerifiesOnN;
 
 import java.util.ArrayList;
 import java.util.Locale;
@@ -220,4 +224,88 @@ public class LocaleUtils {
                 : Locale.getDefault().getCountry();
     }
 
+    /**
+     * Return the language tag of the first language in Configuration.
+     * @param config Configuration to get language for.
+     * @return The BCP 47 tag representation of the configuration's first locale.
+     * Configuration.locale is deprecated on N+. However, read only is equivalent to
+     * Configuration.getLocales()[0]. Change when minSdkVersion >= 24.
+     */
+    @SuppressWarnings("deprecation")
+    public static String getConfigurationLanguage(Configuration config) {
+        Locale locale = config.locale;
+        return (locale != null) ? locale.toLanguageTag() : "";
+    }
+
+    /**
+     * Return the language tag of the first language in the configuration
+     * @param context Context to get language for.
+     * @return The BCP 47 tag representation of the context's first locale.
+     */
+    public static String getContextLanguage(Context context) {
+        return getConfigurationLanguage(context.getResources().getConfiguration());
+    }
+
+    /**
+     * Prepend languageTag to the default locales on config.
+     * @param base The Context to use for the base configuration.
+     * @param config The Configuration to update.
+     * @param languageTag The language to prepend to default locales.
+     */
+    public static void updateConfig(Context base, Configuration config, String languageTag) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            ApisN.setConfigLocales(base, config, languageTag);
+        } else {
+            config.setLocale(Locale.forLanguageTag(languageTag));
+        }
+    }
+
+    /**
+     * Updates the default Locale/LocaleList to those of config.
+     * @param config
+     */
+    public static void setDefaultLocalesFromConfiguration(Configuration config) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            ApisN.setLocaleList(config);
+        } else {
+            Locale.setDefault(config.locale);
+        }
+    }
+
+    /**
+     * Helper class for N only code that is not validated on pre-N devices.
+     */
+    @RequiresApi(Build.VERSION_CODES.N)
+    @VerifiesOnN
+    @VisibleForTesting
+    static class ApisN {
+        static void setConfigLocales(Context base, Configuration config, String language) {
+            LocaleList updatedLocales = prependToLocaleList(
+                    language, base.getResources().getConfiguration().getLocales());
+            config.setLocales(updatedLocales);
+        }
+
+        static void setLocaleList(Configuration config) {
+            LocaleList.setDefault(config.getLocales());
+        }
+
+        /**
+         * Create a new LocaleList with languageTag added to the front.
+         * If languageTag is already in the list the existing tag is moved to the front.
+         * @param languageTag String of language tag to prepend
+         * @param localeList LocaleList to prepend to.
+         * @return LocaleList
+         */
+        static LocaleList prependToLocaleList(String languageTag, LocaleList localeList) {
+            String languageList = localeList.toLanguageTags();
+
+            // Remove the first instance of languageTag with associated comma if present.
+            // Pattern example: "(^|,)en-US$|en-US,"
+            String pattern = String.format("(^|,)%1$s$|%1$s,", languageTag);
+            languageList = languageList.replaceFirst(pattern, "");
+
+            return LocaleList.forLanguageTags(
+                    String.format("%1$s,%2$s", languageTag, languageList));
+        }
+    }
 }

base/android/javatests/src/org/chromium/base/LocaleUtilsTest.java

@@ -5,6 +5,7 @@
 package org.chromium.base;
 
 import android.annotation.SuppressLint;
+import android.content.res.Configuration;
 import android.os.Build;
 import android.os.LocaleList;
 
@@ -272,4 +273,107 @@ public class LocaleUtilsTest {
         Assert.assertEquals("", LocaleUtils.toLanguage(""));
         Assert.assertEquals("fil", LocaleUtils.toLanguage("fil"));
     }
+
+    // Test for getConfigurationLocale < N
+    @Test
+    @SmallTest
+    public void testGetConfigurationLocale() {
+        Configuration config = new Configuration();
+        Assert.assertEquals("", LocaleUtils.getConfigurationLanguage(config));
+
+        config.setLocale(Locale.forLanguageTag("hi-IN"));
+        Assert.assertEquals("hi-IN", LocaleUtils.getConfigurationLanguage(config));
+
+        config.setLocale(new Locale("ar"));
+        Assert.assertEquals("ar", LocaleUtils.getConfigurationLanguage(config));
+    }
+
+    // Test for getConfigurationLocale N+ (with LocaleList)
+    @Test
+    @SmallTest
+    @MinAndroidSdkLevel(Build.VERSION_CODES.N)
+    public void testGetConfigurationN() {
+        Configuration config = new Configuration();
+
+        Locale locale1 = new Locale("hi", "IN");
+        Locale locale2 = new Locale("tl", "PH");
+        LocaleList localeList = new LocaleList(locale1, locale2);
+        config.setLocales(localeList);
+        Assert.assertEquals("hi-IN", LocaleUtils.getConfigurationLanguage(config));
+
+        locale1 = new Locale("ceb");
+        locale2 = new Locale("tl", "PH");
+        localeList = new LocaleList(locale1, locale2);
+        config.setLocales(localeList);
+        Assert.assertEquals("ceb", LocaleUtils.getConfigurationLanguage(config));
+    }
+
+    // Test for setDefaultLocalesFromConfiguration
+    @Test
+    @SmallTest
+    public void testSetDefaultLocalesFromConfiguration() {
+        Configuration config = new Configuration();
+        config.setLocale(new Locale("tl", "PH"));
+        LocaleUtils.setDefaultLocalesFromConfiguration(config);
+        Assert.assertEquals("tl-PH", Locale.getDefault().toLanguageTag());
+
+        config.setLocale(new Locale("es", "AR"));
+        LocaleUtils.setDefaultLocalesFromConfiguration(config);
+        Assert.assertEquals("es-AR", Locale.getDefault().toLanguageTag());
+    }
+
+    // Test for setDefaultLocalesFromConfiguration N+ (with LocaleList)
+    @Test
+    @SmallTest
+    @MinAndroidSdkLevel(Build.VERSION_CODES.N)
+    public void testSetDefaultLocalesFromConfigurationN() {
+        Configuration config = new Configuration();
+        String tags = "tl-PH,es-AR,en";
+        config.setLocales(LocaleList.forLanguageTags(tags));
+        LocaleUtils.setDefaultLocalesFromConfiguration(config);
+        Assert.assertEquals("tl-PH", Locale.getDefault().toLanguageTag());
+        Assert.assertEquals(tags, LocaleList.getDefault().toLanguageTags());
+
+        tags = "en,en-US,en-GB";
+        config.setLocales(LocaleList.forLanguageTags(tags));
+        LocaleUtils.setDefaultLocalesFromConfiguration(config);
+        Assert.assertEquals("en", Locale.getDefault().toLanguageTag());
+        Assert.assertEquals(tags, LocaleList.getDefault().toLanguageTags());
+    }
+
+    // Test for prependToLocaleList
+    @Test
+    @SmallTest
+    @MinAndroidSdkLevel(Build.VERSION_CODES.N)
+    public void testPrependToLocaleList() {
+        // Prepend to empty list
+        LocaleList resultList = LocaleUtils.ApisN.prependToLocaleList("ceb-PH", new LocaleList());
+        Assert.assertEquals("ceb-PH", resultList.toLanguageTags());
+
+        // Prepend and not in list
+        LocaleList baseList = LocaleList.forLanguageTags("en,es-ES,fr");
+        resultList = LocaleUtils.ApisN.prependToLocaleList("zu", baseList);
+        Assert.assertEquals("zu,en,es-ES,fr", resultList.toLanguageTags());
+
+        // Prepend and in middle of list
+        resultList = LocaleUtils.ApisN.prependToLocaleList("es-ES", baseList);
+        Assert.assertEquals("es-ES,en,fr", resultList.toLanguageTags());
+
+        // Prepend and at end of list
+        resultList = LocaleUtils.ApisN.prependToLocaleList("fr", baseList);
+        Assert.assertEquals("fr,en,es-ES", resultList.toLanguageTags());
+
+        // Prepend and at front of list
+        resultList = LocaleUtils.ApisN.prependToLocaleList("en", baseList);
+        Assert.assertEquals("en,es-ES,fr", resultList.toLanguageTags());
+
+        // Prepend to list of one
+        baseList = LocaleList.forLanguageTags("fr");
+        resultList = LocaleUtils.ApisN.prependToLocaleList("en", baseList);
+        Assert.assertEquals("en,fr", resultList.toLanguageTags());
+
+        // Prepend to list of one (self)
+        resultList = LocaleUtils.ApisN.prependToLocaleList("fr", baseList);
+        Assert.assertEquals("fr", resultList.toLanguageTags());
+    }
 }

chrome/android/chrome_java_sources.gni

@@ -870,6 +870,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/invalidation/ChromeBrowserSyncAdapterService.java",
   "java/src/org/chromium/chrome/browser/invalidation/ResumableDelayedTaskRunner.java",
   "java/src/org/chromium/chrome/browser/invalidation/SessionsInvalidationManager.java",
+  "java/src/org/chromium/chrome/browser/language/AppLocaleUtils.java",
   "java/src/org/chromium/chrome/browser/language/LanguageAskPrompt.java",
   "java/src/org/chromium/chrome/browser/language/settings/AddLanguageFragment.java",
   "java/src/org/chromium/chrome/browser/language/settings/LanguageItem.java",

chrome/android/chrome_test_java_sources.gni

@@ -249,6 +249,7 @@ chrome_test_java_sources = [
   "javatests/src/org/chromium/chrome/browser/interstitials/LookalikeInterstitialTest.java",
   "javatests/src/org/chromium/chrome/browser/jsdialog/JavascriptAppModalDialogTest.java",
   "javatests/src/org/chromium/chrome/browser/jsdialog/JavascriptTabModalDialogTest.java",
+  "javatests/src/org/chromium/chrome/browser/language/AppLocaleUtilsTest.java",
   "javatests/src/org/chromium/chrome/browser/language/settings/LanguageSettingsTest.java",
   "javatests/src/org/chromium/chrome/browser/locale/DefaultSearchEngineDialogHelperTest.java",
   "javatests/src/org/chromium/chrome/browser/locale/DefaultSearchEngineDialogHelperUtils.java",

chrome/android/java/src/org/chromium/chrome/browser/language/AppLocaleUtils.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.language;
+
+import android.text.TextUtils;
+
+import com.google.android.play.core.splitinstall.SplitInstallManager;
+import com.google.android.play.core.splitinstall.SplitInstallManagerFactory;
+import com.google.android.play.core.splitinstall.SplitInstallRequest;
+
+import org.chromium.base.BundleUtils;
+import org.chromium.base.ContextUtils;
+import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
+import org.chromium.chrome.browser.preferences.SharedPreferencesManager;
+
+import java.util.Locale;
+
+/**
+ * Provides utility functions to assist with overriding the application language.
+ * This class manages the AppLanguagePref.
+ */
+public class AppLocaleUtils {
+    private AppLocaleUtils(){};
+
+    /**
+     * Return true if languageName is the same as the current application override
+     * language stored preference.
+     * @return boolean
+     */
+    public static boolean isAppLanguagePref(String languageName) {
+        return TextUtils.equals(getAppLanguagePref(), languageName);
+    }
+
+    /**
+     * Get the value of application language shared preference or null if there is none.
+     * @return String
+     */
+    public static String getAppLanguagePref() {
+        return SharedPreferencesManager.getInstance().readString(
+                ChromePreferenceKeys.APPLICATION_OVERRIDE_LANGUAGE, null);
+    }
+
+    /**
+     * Set the value of application language shared preference. If set to null
+     * the system language will be used.
+     */
+    public static void setAppLanguagePref(String languageName) {
+        SharedPreferencesManager.getInstance().writeString(
+                ChromePreferenceKeys.APPLICATION_OVERRIDE_LANGUAGE, languageName);
+        if (BundleUtils.isBundle()) {
+            ensureLaguageSplitInstalled(languageName);
+        }
+    }
+
+    /**
+     * For bundle builds ensure that the language split for languageName is download.
+     */
+    private static void ensureLaguageSplitInstalled(String languageName) {
+        SplitInstallManager splitInstallManager =
+                SplitInstallManagerFactory.create(ContextUtils.getApplicationContext());
+
+        // TODO(perrier): check if languageName is already installed. https://crbug.com/1103806
+        if (languageName != null) {
+            SplitInstallRequest installRequest =
+                    SplitInstallRequest.newBuilder()
+                            .addLanguage(Locale.forLanguageTag(languageName))
+                            .build();
+            splitInstallManager.startInstall(installRequest);
+        }
+    }
+}

chrome/android/javatests/src/org/chromium/chrome/browser/language/AppLocaleUtilsTest.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.language;
+
+import androidx.test.filters.SmallTest;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.chrome.browser.flags.ChromeSwitches;
+import org.chromium.chrome.browser.preferences.ChromePreferenceKeys;
+import org.chromium.chrome.browser.preferences.SharedPreferencesManager;
+import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
+
+/**
+ * Tests for the AppLocalUtils class.
+ */
+@RunWith(ChromeJUnit4ClassRunner.class)
+@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
+public class AppLocaleUtilsTest {
+    // Test getAppLanguagePref.
+    @Test
+    @SmallTest
+    public void testGetAppLanguagePref() {
+        String lang = AppLocaleUtils.getAppLanguagePref();
+        Assert.assertEquals(null, lang);
+
+        AppLocaleUtils.setAppLanguagePref("en-US");
+        lang = AppLocaleUtils.getAppLanguagePref();
+        Assert.assertEquals("en-US", lang);
+    }
+
+    // Test setAppLanguagePref.
+    @Test
+    @SmallTest
+    public void testSetAppLanguagePref() {
+        assertLanguagePrefEquals(null);
+
+        AppLocaleUtils.setAppLanguagePref("en-US");
+        assertLanguagePrefEquals("en-US");
+
+        AppLocaleUtils.setAppLanguagePref("fr");
+        assertLanguagePrefEquals("fr");
+    }
+
+    // Test isAppLanguagePref.
+    @Test
+    @SmallTest
+    public void testIsAppLanguagePref() {
+        Assert.assertFalse(AppLocaleUtils.isAppLanguagePref("en"));
+
+        AppLocaleUtils.setAppLanguagePref("en-US");
+        Assert.assertTrue(AppLocaleUtils.isAppLanguagePref("en-US"));
+
+        Assert.assertFalse(AppLocaleUtils.isAppLanguagePref("en"));
+    }
+
+    // Helper function to manually get and check AppLanguagePref.
+    private void assertLanguagePrefEquals(String language) {
+        Assert.assertEquals(language,
+                SharedPreferencesManager.getInstance().readString(
+                        ChromePreferenceKeys.APPLICATION_OVERRIDE_LANGUAGE, null));
+    }
+}

chrome/browser/preferences/android/java/src/org/chromium/chrome/browser/preferences/ChromePreferenceKeys.java

@@ -42,13 +42,17 @@ import java.util.List;
  * sanity of this file.
  */
 public final class ChromePreferenceKeys {
-    /*
+    /**
      * Whether the simplified tab switcher is enabled when accessibility mode is enabled. Keep in
      * sync with accessibility_preferences.xml.
      * Default value is true.
      */
     public static final String ACCESSIBILITY_TAB_SWITCHER = "accessibility_tab_switcher";
 
+    /** The language code to override application language with. */
+    public static final String APPLICATION_OVERRIDE_LANGUAGE =
+            "Chrome.Language.ApplicationOverrideLanguage";
+
     public static final String APP_LOCALE = "locale";
 
     /** Whether Autofill Assistant is enabled */
@@ -791,6 +795,7 @@ public final class ChromePreferenceKeys {
         return Arrays.asList(
                 AUTOFILL_ASSISTANT_FIRST_TIME_LITE_SCRIPT_USER,
                 AUTOFILL_ASSISTANT_NUMBER_OF_LITE_SCRIPTS_CANCELED,
+                APPLICATION_OVERRIDE_LANGUAGE,
                 CLIPBOARD_SHARED_URI,
                 CONDITIONAL_TAB_STRIP_CONTINUOUS_DISMISS_COUNTER,
                 CONDITIONAL_TAB_STRIP_FEATURE_STATUS,