Adds Compose Email Settings UI for deprecating Native App Launcher

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

 // Copyright 2013 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/content_settings_collection_view_controller.h"
 
 #include "base/logging.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_types.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/prefs/pref_service.h"
 #include "components/strings/grit/components_strings.h"
 #include "components/translate/core/browser/translate_pref_names.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/content_settings/host_content_settings_map_factory.h"
+#include "ios/chrome/browser/experimental_flags.h"
 #import "ios/chrome/browser/prefs/pref_observer_bridge.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_detail_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
 #import "ios/chrome/browser/ui/settings/block_popups_collection_view_controller.h"
+#import "ios/chrome/browser/ui/settings/compose_email_handler_collection_view_controller.h"
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
 #import "ios/chrome/browser/ui/settings/translate_collection_view_controller.h"
 #import "ios/chrome/browser/ui/settings/utils/content_setting_backed_boolean.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/third_party/material_components_ios/src/components/CollectionCells/src/MaterialCollectionCells.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 
 typedef NS_ENUM(NSInteger, SectionIdentifier) {
   SectionIdentifierSettings = kSectionIdentifierEnumZero,
 };
 
 typedef NS_ENUM(NSInteger, ItemType) {
   ItemTypeSettingsBlockPopups = kItemTypeEnumZero,
   ItemTypeSettingsTranslate,
+  ItemTypeSettingsComposeEmail,
 };
 
 }  // namespace
 
 @interface ContentSettingsCollectionViewController ()<PrefObserverDelegate,
                                                       BooleanObserver> {
   // Pref observer to track changes to prefs.
   std::unique_ptr<PrefObserverBridge> _prefObserverBridge;
   // Registrar for pref changes notifications.
   PrefChangeRegistrar _prefChangeRegistrar;
 
   // The observable boolean that binds to the "Disable Popups" setting state.
   ContentSettingBackedBoolean* _disablePopupsSetting;
 
+  // This object contains the list of available Mail client apps that can
+  // handle mailto: URLs. The value can be nil if mailto: URL rewriting is
+  // not available because of experimental settings.
+  MailtoURLRewriter* _mailtoURLRewriter;
+
   // Updatable Items
   CollectionViewDetailItem* _blockPopupsDetailItem;
   CollectionViewDetailItem* _translateDetailItem;
+  CollectionViewDetailItem* _composeEmailDetailItem;
 }
 
 // Returns the value for the default setting with ID |settingID|.
 - (ContentSetting)getContentSetting:(ContentSettingsType)settingID;
 
 // Helpers to create collection view items.
 - (id)blockPopupsItem;
 - (id)translateItem;
+- (id)composeEmailItem;
 
 @end
 
 @implementation ContentSettingsCollectionViewController {
   ios::ChromeBrowserState* browserState_;  // weak
 }
 
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState {
   DCHECK(browserState);
   self = [super initWithStyle:CollectionViewControllerStyleAppBar];
   if (self) {
     browserState_ = browserState;
     self.title = l10n_util::GetNSString(IDS_IOS_CONTENT_SETTINGS_TITLE);
 
     _prefChangeRegistrar.Init(browserState->GetPrefs());
     _prefObserverBridge.reset(new PrefObserverBridge(self));
     // Register to observe any changes on Perf backed values displayed by the
     // screen.
     _prefObserverBridge->ObserveChangesForPreference(prefs::kEnableTranslate,
                                                      &_prefChangeRegistrar);
 
     HostContentSettingsMap* settingsMap =
         ios::HostContentSettingsMapFactory::GetForBrowserState(browserState);
     _disablePopupsSetting = [[ContentSettingBackedBoolean alloc]
         initWithHostContentSettingsMap:settingsMap
                              settingID:CONTENT_SETTINGS_TYPE_POPUPS
                               inverted:YES];
     [_disablePopupsSetting setObserver:self];
 
+    if (!experimental_flags::IsNativeAppLauncherEnabled()) {
+      _mailtoURLRewriter = [[MailtoURLRewriter alloc] initWithStandardHandlers];
+      [_mailtoURLRewriter setObserver:self];
+    }
+
     [self loadModel];
   }
   return self;
 }
 
 - (void)dealloc {
   [_disablePopupsSetting setObserver:nil];
 }
 
 - (instancetype)init {
   NOTREACHED();
   return nil;
 }
 
 - (void)loadModel {
   [super loadModel];
 
   CollectionViewModel* model = self.collectionViewModel;
   [model addSectionWithIdentifier:SectionIdentifierSettings];
   [model addItem:[self blockPopupsItem]
       toSectionWithIdentifier:SectionIdentifierSettings];
   [model addItem:[self translateItem]
       toSectionWithIdentifier:SectionIdentifierSettings];
+  if (!experimental_flags::IsNativeAppLauncherEnabled() &&
+      [[_mailtoURLRewriter defaultHandlers] count] > 1) {
+    [model addItem:[self composeEmailItem]
+        toSectionWithIdentifier:SectionIdentifierSettings];
+  }
 }
 
 - (CollectionViewItem*)blockPopupsItem {
   _blockPopupsDetailItem = [[CollectionViewDetailItem alloc]
       initWithType:ItemTypeSettingsBlockPopups];
   NSString* subtitle = [_disablePopupsSetting value]
                            ? l10n_util::GetNSString(IDS_IOS_SETTING_ON)
                            : l10n_util::GetNSString(IDS_IOS_SETTING_OFF);
   _blockPopupsDetailItem.text = l10n_util::GetNSString(IDS_IOS_BLOCK_POPUPS);
   _blockPopupsDetailItem.detailText = subtitle;
@@ skipping 10 matching lines @@
   NSString* subtitle = enabled ? l10n_util::GetNSString(IDS_IOS_SETTING_ON)
                                : l10n_util::GetNSString(IDS_IOS_SETTING_OFF);
   _translateDetailItem.text = l10n_util::GetNSString(IDS_IOS_TRANSLATE_SETTING);
   _translateDetailItem.detailText = subtitle;
   _translateDetailItem.accessoryType =
       MDCCollectionViewCellAccessoryDisclosureIndicator;
   _translateDetailItem.accessibilityTraits |= UIAccessibilityTraitButton;
   return _translateDetailItem;
 }
 
+- (CollectionViewItem*)composeEmailItem {
+  _composeEmailDetailItem = [[CollectionViewDetailItem alloc]
+      initWithType:ItemTypeSettingsComposeEmail];
+  _composeEmailDetailItem.text =
+      l10n_util::GetNSString(IDS_IOS_COMPOSE_EMAIL_SETTING);
+  _composeEmailDetailItem.detailText = [_mailtoURLRewriter defaultHandlerName];
+  _composeEmailDetailItem.accessoryType =
+      MDCCollectionViewCellAccessoryDisclosureIndicator;
+  _composeEmailDetailItem.accessibilityTraits |= UIAccessibilityTraitButton;
+  return _composeEmailDetailItem;
+}
+
 - (ContentSetting)getContentSetting:(ContentSettingsType)settingID {
   return ios::HostContentSettingsMapFactory::GetForBrowserState(browserState_)
       ->GetDefaultContentSetting(settingID, NULL);
 }
 
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
   [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
 
   NSInteger itemType =
       [self.collectionViewModel itemTypeForIndexPath:indexPath];
   switch (itemType) {
     case ItemTypeSettingsBlockPopups: {
       UIViewController* controller =
           [[BlockPopupsCollectionViewController alloc]
               initWithBrowserState:browserState_];
       [self.navigationController pushViewController:controller animated:YES];
       break;
     }
     case ItemTypeSettingsTranslate: {
       UIViewController* controller = [[TranslateCollectionViewController alloc]
           initWithPrefs:browserState_->GetPrefs()];
       [self.navigationController pushViewController:controller animated:YES];
       break;
     }
+    case ItemTypeSettingsComposeEmail: {
+      UIViewController* controller =
+          [[ComposeEmailHandlerCollectionViewController alloc]
+              initWithRewriter:_mailtoURLRewriter];
+      [self.navigationController pushViewController:controller animated:YES];
+      break;
+    }
   }
 }
 
 #pragma mark - PrefObserverDelegate
 
 - (void)onPreferenceChanged:(const std::string&)preferenceName {
   if (preferenceName == prefs::kEnableTranslate) {
     BOOL enabled = browserState_->GetPrefs()->GetBoolean(preferenceName);
     NSString* subtitle = enabled ? l10n_util::GetNSString(IDS_IOS_SETTING_ON)
                                  : l10n_util::GetNSString(IDS_IOS_SETTING_OFF);
@@ skipping 10 matching lines @@
   NSString* subtitle = [_disablePopupsSetting value]
                            ? l10n_util::GetNSString(IDS_IOS_SETTING_ON)
                            : l10n_util::GetNSString(IDS_IOS_SETTING_OFF);
   // Update the item.
   _blockPopupsDetailItem.detailText = subtitle;
 
   // Update the cell.
   [self reconfigureCellsForItems:@[ _blockPopupsDetailItem ]];
 }
 
+#pragma mark - MailtoURLRewriterObserver
+
+- (void)rewriterDidChange:(MailtoURLRewriter*)rewriter {
+  if (rewriter != _mailtoURLRewriter)
+    return;
+  _composeEmailDetailItem.detailText = [rewriter defaultHandlerName];
+  [self reconfigureCellsForItems:@[ _composeEmailDetailItem ]];
+}
+
 @end