[IOS][Language] Language Settings - main page

Language Settings page features a list of user preferred languages sent in
the Accept-Language HTTP header. Users can add, delete, and reorder these
languages.

Language Settings page also features a switch to enable/disable translation.
If enabled, a trailing label appears for every language row indicating
whether or not translate is offered for that language. A disclosure
indicator is also added to every language row indicating this option can be
changed.

1. In edit mode, the "Translate" and "Add Language..." buttons are disabled.
2. Languages can be deleted by swiping gesture or the red delete button in
   edit mode.
3. The last Translate-blocked language cannot be deleted similar to other
   platforms.
4. Translate cannot be offered for the last Translate-blocked language;
   therefore the option to "Offer Translate" is disabled for it.
5. Translate cannot be offered for the target language (which may not
   appear in the list, e.g., the device language); therefore the option to
   "Offer Translate" is disabled for it.

Demo: https://drive.google.com/file/d/0B2sUCLY7X-D2enZRZE9hUmUwa0pjNkpYWHVFbzV6cEhDbUVr/view?usp=sharing

Bug: 957688
Change-Id: Icdf005e04d1716c42ea249229dbc7f39a043e46f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1595040Reviewed-by: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658758}

ios/chrome/browser/ui/settings/BUILD.gn

@@ -54,6 +54,8 @@ source_set("settings") {
     "handoff_table_view_controller.mm",
     "import_data_table_view_controller.h",
     "import_data_table_view_controller.mm",
+    "language_settings_table_view_controller.h",
+    "language_settings_table_view_controller.mm",
     "material_cell_catalog_view_controller.h",
     "material_cell_catalog_view_controller.mm",
     "privacy_table_view_controller.h",
@@ -82,6 +84,7 @@ source_set("settings") {
     "resources:settings_content_settings",
     "resources:settings_debug",
     "resources:settings_error",
+    "resources:settings_language_settings",
     "resources:settings_passwords",
     "resources:settings_payment_methods",
     "resources:settings_privacy",
@@ -105,6 +108,8 @@ source_set("settings") {
     "//components/history/core/browser",
     "//components/image_fetcher/ios",
     "//components/keyed_service/core",
+    "//components/language/core/browser",
+    "//components/language/core/common",
     "//components/metrics",
     "//components/password_manager/core/browser",
     "//components/password_manager/core/common",
@@ -130,6 +135,7 @@ source_set("settings") {
     "//ios/chrome/browser/favicon",
     "//ios/chrome/browser/feature_engagement",
     "//ios/chrome/browser/history",
+    "//ios/chrome/browser/language",
     "//ios/chrome/browser/mailto:feature_flags",
     "//ios/chrome/browser/passwords",
     "//ios/chrome/browser/search_engines",

ios/chrome/browser/ui/settings/cells/BUILD.gn

@@ -14,6 +14,8 @@ source_set("cells") {
     "clear_browsing_data_item.mm",
     "copied_to_chrome_item.h",
     "copied_to_chrome_item.mm",
+    "language_item.h",
+    "language_item.mm",
     "passphrase_error_item.h",
     "passphrase_error_item.mm",
     "search_engine_item.h",

ios/chrome/browser/ui/settings/cells/language_item.h

+// Copyright 2019 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_SETTINGS_CELLS_LANGUAGE_ITEM_H_
+#define IOS_CHROME_BROWSER_UI_SETTINGS_CELLS_LANGUAGE_ITEM_H_
+
+#import "ios/chrome/browser/ui/table_view/cells/table_view_multi_detail_text_item.h"
+
+// Contains the model data for a language in the Language Settings page.
+@interface LanguageItem : TableViewMultiDetailTextItem
+
+// The language code for this language.
+@property(nonatomic, assign) std::string languageCode;
+
+// Whether the language is Translate-blocked.
+@property(nonatomic, getter=isBlocked) BOOL blocked;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_SETTINGS_CELLS_LANGUAGE_ITEM_H_

ios/chrome/browser/ui/settings/cells/language_item.mm

+// Copyright 2019 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.
+
+#import "ios/chrome/browser/ui/settings/cells/language_item.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation LanguageItem
+
+@end

ios/chrome/browser/ui/settings/language_settings_table_view_controller.h

+// Copyright 2019 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_SETTINGS_TABLE_VIEW_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_SETTINGS_TABLE_VIEW_CONTROLLER_H_
+
+#import "ios/chrome/browser/ui/settings/settings_root_table_view_controller.h"
+
+namespace ios {
+class ChromeBrowserState;
+}  // namespace ios
+
+// Controller for the UI that allows the user to change language settings such
+// as user preferred languages.
+@interface LanguageSettingsTableViewController : SettingsRootTableViewController
+
+// The designated initializer. |browserState| must not be nil and is not
+// retained.
+- (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState
+    NS_DESIGNATED_INITIALIZER;
+- (instancetype)initWithTableViewStyle:(UITableViewStyle)style
+                           appBarStyle:
+                               (ChromeTableViewControllerStyle)appBarStyle
+    NS_UNAVAILABLE;
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_SETTINGS_LANGUAGE_SETTINGS_TABLE_VIEW_CONTROLLER_H_

ios/chrome/browser/ui/settings/resources/BUILD.gn

@@ -94,6 +94,14 @@ imageset("settings_debug") {
   ]
 }
 
+imageset("settings_language_settings") {
+  sources = [
+    "settings_language_settings.imageset/Contents.json",
+    "settings_language_settings.imageset/settings_language_settings@2x.png",
+    "settings_language_settings.imageset/settings_language_settings@3x.png",
+  ]
+}
+
 imageset("settings_passwords") {
   sources = [
     "settings_passwords.imageset/Contents.json",

ios/chrome/browser/ui/settings/resources/settings_language_settings.imageset/Contents.json

+{
+    "images": [
+        {
+            "idiom": "universal",
+            "scale": "2x",
+            "filename": "settings_language_settings@2x.png"
+        },
+        {
+            "idiom": "universal",
+            "scale": "3x",
+            "filename": "settings_language_settings@3x.png"
+        }
+    ],
+    "info": {
+        "version": 1,
+        "author": "xcode"
+    }
+}

ios/chrome/browser/ui/settings/settings_table_view_controller.mm

@@ -50,6 +50,7 @@
 #import "ios/chrome/browser/ui/settings/content_settings_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/google_services/accounts_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/google_services/google_services_settings_coordinator.h"
+#import "ios/chrome/browser/ui/settings/language_settings_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/material_cell_catalog_view_controller.h"
 #import "ios/chrome/browser/ui/settings/password/passwords_table_view_controller.h"
 #import "ios/chrome/browser/ui/settings/privacy_table_view_controller.h"
@@ -109,6 +110,8 @@ NSString* const kSettingsAutofillCreditCardImageName =
 NSString* const kSettingsAutofillProfileImageName = @"settings_addresses";
 NSString* const kSettingsVoiceSearchImageName = @"settings_voice_search";
 NSString* const kSettingsPrivacyImageName = @"settings_privacy";
+NSString* const kSettingsLanguageSettingsImageName =
+    @"settings_language_settings";
 NSString* const kSettingsContentSettingsImageName =
     @"settings_content_settings";
 NSString* const kSettingsBandwidthImageName = @"settings_bandwidth";
@@ -138,6 +141,7 @@ typedef NS_ENUM(NSInteger, ItemType) {
   ItemTypeAutofillProfile,
   ItemTypeVoiceSearch,
   ItemTypePrivacy,
+  ItemTypeLanguageSettings,
   ItemTypeContentSettings,
   ItemTypeBandwidth,
   ItemTypeAboutChrome,
@@ -442,6 +446,10 @@ void IdentityObserverBridge::OnPrimaryAccountCleared(
   _articlesForYouItem = [self articlesForYouSwitchItem];
   [model addItem:_articlesForYouItem
       toSectionWithIdentifier:SectionIdentifierAdvanced];
+  if (base::FeatureList::IsEnabled(kLanguageSettings)) {
+    [model addItem:[self languageSettingsDetailItem]
+        toSectionWithIdentifier:SectionIdentifierAdvanced];
+  }
   [model addItem:[self contentSettingsDetailItem]
       toSectionWithIdentifier:SectionIdentifierAdvanced];
   [model addItem:[self bandwidthManagementDetailItem]
@@ -620,6 +628,14 @@ void IdentityObserverBridge::OnPrimaryAccountCleared(
                  iconImageName:kSettingsPrivacyImageName];
 }
 
+- (TableViewItem*)languageSettingsDetailItem {
+  return [self
+      detailItemWithType:ItemTypeLanguageSettings
+                    text:l10n_util::GetNSString(IDS_IOS_LANGUAGE_SETTINGS_TITLE)
+              detailText:nil
+           iconImageName:kSettingsLanguageSettingsImageName];
+}
+
 - (TableViewItem*)contentSettingsDetailItem {
   return [self
       detailItemWithType:ItemTypeContentSettings
@@ -847,6 +863,10 @@ void IdentityObserverBridge::OnPrimaryAccountCleared(
       controller = [[PrivacyTableViewController alloc]
           initWithBrowserState:_browserState];
       break;
+    case ItemTypeLanguageSettings:
+      controller = [[LanguageSettingsTableViewController alloc]
+          initWithBrowserState:_browserState];
+      break;
     case ItemTypeContentSettings:
       controller = [[ContentSettingsTableViewController alloc]
           initWithBrowserState:_browserState];