ios/chrome/browser/ui/partial_translate/partial_translate_mediator.mm - chromium/src - Git at Google

 // Copyright 2023 The Chromium Authors
 // 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/partial_translate/partial_translate_mediator.h"

 #import "base/apple/foundation_util.h"
 #import "base/memory/weak_ptr.h"
 #import "base/metrics/histogram_functions.h"
 #import "components/prefs/pref_member.h"
 #import "components/strings/grit/components_strings.h"
 #import "components/translate/core/browser/translate_pref_names.h"
 #import "ios/chrome/browser/shared/model/web_state_list/web_state_list.h"
 #import "ios/chrome/browser/shared/public/commands/browser_coordinator_commands.h"
 #import "ios/chrome/browser/shared/public/features/features.h"
 #import "ios/chrome/browser/shared/ui/symbols/symbols.h"
 #import "ios/chrome/browser/ui/browser_container/edit_menu_alert_delegate.h"
 #import "ios/chrome/browser/ui/fullscreen/fullscreen_controller.h"
 #import "ios/chrome/browser/web_selection/web_selection_response.h"
 #import "ios/chrome/browser/web_selection/web_selection_tab_helper.h"
 #import "ios/chrome/grit/ios_strings.h"
 #import "ios/public/provider/chrome/browser/partial_translate/partial_translate_api.h"
 #import "ios/web/public/web_state.h"
 #import "ui/base/l10n/l10n_util_mac.h"

 namespace {
 typedef void (^ProceduralBlockWithItemArray)(NSArray<UIMenuElement*>*);
 typedef void (^ProceduralBlockWithBlockWithItemArray)(
     ProceduralBlockWithItemArray);

 enum class PartialTranslateError {
   kSelectionTooLong,
   kSelectionEmpty,
   kGenericError
 };

 // These values are persisted to logs. Entries should not be renumbered and
 // numeric values should never be reused.
 enum class PartialTranslateOutcomeStatus {
   kSuccess,
   kTooLongCancel,
   kTooLongFullTranslate,
   kEmptyCancel,
   kEmptyFullTranslate,
   kErrorCancel,
   kErrorFullTranslate,
   kMaxValue = kErrorFullTranslate
 };

 void ReportOutcome(PartialTranslateOutcomeStatus outcome) {
   base::UmaHistogramEnumeration("IOS.PartialTranslate.Outcome", outcome);
 }

 void ReportErrorOutcome(PartialTranslateError error, bool went_full) {
   switch (error) {
     case PartialTranslateError::kSelectionTooLong:
       if (went_full) {
         ReportOutcome(PartialTranslateOutcomeStatus::kTooLongFullTranslate);
       } else {
         ReportOutcome(PartialTranslateOutcomeStatus::kTooLongCancel);
       }
       break;
     case PartialTranslateError::kSelectionEmpty:
       if (went_full) {
         ReportOutcome(PartialTranslateOutcomeStatus::kEmptyFullTranslate);
       } else {
         ReportOutcome(PartialTranslateOutcomeStatus::kEmptyCancel);
       }
       break;
     case PartialTranslateError::kGenericError:
       if (went_full) {
         ReportOutcome(PartialTranslateOutcomeStatus::kErrorFullTranslate);
       } else {
         ReportOutcome(PartialTranslateOutcomeStatus::kErrorCancel);
       }
       break;
   }
 }

 // Character limit for the partial translate feature.
 // A string longer than that will trigger a full page translate.
 const NSUInteger kPartialTranslateCharactersLimit = 1000;

 }  // anonymous namespace

 @interface PartialTranslateMediator ()

 // Whether the mediator is handling partial translate for an incognito tab.
 @property(nonatomic, weak) UIViewController* baseViewController;

 // Whether the mediator is handling partial translate for an incognito tab.
 @property(nonatomic, assign) BOOL incognito;

 // The controller to display Partial Translate.
 @property(nonatomic, strong) id<PartialTranslateController> controller;

 @end

 @implementation PartialTranslateMediator {
   BooleanPrefMember _translateEnabled;

   // The Browser's WebStateList.
   base::WeakPtr<WebStateList> _webStateList;

   // The fullscreen controller to offset sourceRect depending on fullscreen
   // status.
   FullscreenController* _fullscreenController;
 }

 - (instancetype)initWithWebStateList:(WebStateList*)webStateList
               withBaseViewController:(UIViewController*)baseViewController
                          prefService:(PrefService*)prefs
                 fullscreenController:(FullscreenController*)fullscreenController
                            incognito:(BOOL)incognito {
   if (self = [super init]) {
     DCHECK(webStateList);
     DCHECK(baseViewController);
     _webStateList = webStateList->AsWeakPtr();
     _baseViewController = baseViewController;
     _fullscreenController = fullscreenController;
     _incognito = incognito;
     _translateEnabled.Init(translate::prefs::kOfferTranslateEnabled, prefs);
   }
   return self;
 }

 - (void)shutdown {
   _translateEnabled.Destroy();
   _fullscreenController = nullptr;
 }

 - (void)handlePartialTranslateSelection {
   DCHECK(base::FeatureList::IsEnabled(kIOSEditMenuPartialTranslate));
   WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
   if (!tabHelper) {
     return;
   }

   __weak __typeof(self) weakSelf = self;
   tabHelper->GetSelectedText(base::BindOnce(^(WebSelectionResponse* response) {
     [weakSelf receivedWebSelectionResponse:response];
   }));
 }

 - (BOOL)canHandlePartialTranslateSelection {
   DCHECK(base::FeatureList::IsEnabled(kIOSEditMenuPartialTranslate));
   WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
   if (!tabHelper) {
     return NO;
   }
   return tabHelper->CanRetrieveSelectedText() &&
          ios::provider::PartialTranslateLimitMaxCharacters() > 0u;
 }

 - (BOOL)shouldInstallPartialTranslate {
   if (ios::provider::PartialTranslateLimitMaxCharacters() == 0u) {
     // Feature is not available.
     return NO;
   }
   if (!IsPartialTranslateEnabled()) {
     // Feature is not enabled.
     return NO;
   }
   if (self.incognito && !ShouldShowPartialTranslateInIncognito()) {
     // Feature is enabled, but disabled in incognito, and the current tab is in
     // incognito.
     return NO;
   }
   if (!_translateEnabled.GetValue() && _translateEnabled.IsManaged()) {
     // Translate is a managed settings and disabled.
     return NO;
   }
   return YES;
 }

 - (void)switchToFullTranslateWithError:(PartialTranslateError)error {
   if (!self.alertDelegate) {
     return;
   }
   NSString* message;
   switch (error) {
     case PartialTranslateError::kSelectionTooLong:
       message = l10n_util::GetNSString(
           IDS_IOS_PARTIAL_TRANSLATE_ERROR_STRING_TOO_LONG_ERROR);
       break;
     case PartialTranslateError::kSelectionEmpty:
       message =
           l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_ERROR_STRING_EMPTY);
       break;
     case PartialTranslateError::kGenericError:
       message = l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_ERROR_GENERIC);
       break;
   }
   DCHECK(message);
   __weak __typeof(self) weakSelf = self;
   EditMenuAlertDelegateAction* cancelAction =
       [[EditMenuAlertDelegateAction alloc]
           initWithTitle:l10n_util::GetNSString(IDS_CANCEL)
                  action:^{
                    ReportErrorOutcome(error, false);
                  }
                   style:UIAlertActionStyleCancel
               preferred:NO];
   EditMenuAlertDelegateAction* translateAction = [[EditMenuAlertDelegateAction
       alloc]
       initWithTitle:l10n_util::GetNSString(
                         IDS_IOS_PARTIAL_TRANSLATE_ACTION_TRANSLATE_FULL_PAGE)
              action:^{
                ReportErrorOutcome(error, true);
                [weakSelf triggerFullTranslate];
              }
               style:UIAlertActionStyleDefault
           preferred:YES];

   [self.alertDelegate
       showAlertWithTitle:
           l10n_util::GetNSString(
               IDS_IOS_PARTIAL_TRANSLATE_SWITCH_FULL_PAGE_TRANSLATION)
                  message:message
                  actions:@[ cancelAction, translateAction ]];
 }

 - (void)receivedWebSelectionResponse:(WebSelectionResponse*)response {
   DCHECK(response);
   base::UmaHistogramCounts10000("IOS.PartialTranslate.SelectionLength",
                                 response.selectedText.length);
   if (response.selectedText.length >
       std::min(ios::provider::PartialTranslateLimitMaxCharacters(),
                kPartialTranslateCharactersLimit)) {
     return [self switchToFullTranslateWithError:PartialTranslateError::
                                                     kSelectionTooLong];
   }
   if (!response.valid ||
       [[response.selectedText
           stringByTrimmingCharactersInSet:[NSCharacterSet
                                               whitespaceAndNewlineCharacterSet]]
           length] == 0u) {
     return [self
         switchToFullTranslateWithError:PartialTranslateError::kSelectionEmpty];
   }

   CGRect sourceRect = response.sourceRect;
   if (_fullscreenController && !CGRectEqualToRect(sourceRect, CGRectZero)) {
     UIEdgeInsets fullscreenInset =
         _fullscreenController->GetCurrentViewportInsets();
     sourceRect.origin.y += fullscreenInset.top;
     sourceRect.origin.x += fullscreenInset.left;
   }

   self.controller = ios::provider::NewPartialTranslateController(
       response.selectedText, sourceRect, self.incognito);
   __weak __typeof(self) weakSelf = self;
   [self.controller presentOnViewController:self.baseViewController
                      flowCompletionHandler:^(BOOL success) {
                        weakSelf.controller = nil;
                        if (success) {
                          ReportOutcome(PartialTranslateOutcomeStatus::kSuccess);
                        } else {
                          [weakSelf switchToFullTranslateWithError:
                                        PartialTranslateError::kGenericError];
                        }
                      }];
 }

 - (void)triggerFullTranslate {
   [self.browserHandler showTranslate];
 }

 - (WebSelectionTabHelper*)webSelectionTabHelper {
   web::WebState* webState =
       _webStateList ? _webStateList->GetActiveWebState() : nullptr;
   if (!webState) {
     return nullptr;
   }
   WebSelectionTabHelper* helper = WebSelectionTabHelper::FromWebState(webState);
   return helper;
 }

 - (void)addItemWithCompletion:(ProceduralBlockWithItemArray)completion {
   if (![self canHandlePartialTranslateSelection]) {
     completion(@[]);
     return;
   }
   WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
   if (!tabHelper) {
     completion(@[]);
     return;
   }

   __weak __typeof(self) weakSelf = self;
   tabHelper->GetSelectedText(base::BindOnce(^(WebSelectionResponse* response) {
     if (weakSelf) {
       [weakSelf addItemWithResponse:response completion:completion];
     } else {
       completion(@[]);
     }
   }));
 }

 - (void)addItemWithResponse:(WebSelectionResponse*)response
                  completion:(ProceduralBlockWithItemArray)completion {
   __weak __typeof(self) weakSelf = self;
   if (!response.valid ||
       [[response.selectedText
           stringByTrimmingCharactersInSet:[NSCharacterSet
                                               whitespaceAndNewlineCharacterSet]]
           length] == 0u) {
     completion(@[]);
     return;
   }
   NSString* title =
       l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_EDIT_MENU_ENTRY);
   NSString* partialTranslateId = @"chromecommand.partialTranslate";
   UIAction* action =
       [UIAction actionWithTitle:title
                           image:CustomSymbolWithPointSize(
                                     kTranslateSymbol, kSymbolActionPointSize)
                      identifier:partialTranslateId
                         handler:^(UIAction* a) {
                           [weakSelf receivedWebSelectionResponse:response];
                         }];
   completion(@[ action ]);
 }

 #pragma mark - EditMenuProvider

 - (void)buildMenuWithBuilder:(id<UIMenuBuilder>)builder {
   if (![self shouldInstallPartialTranslate]) {
     return;
   }
   NSString* title =
       l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_EDIT_MENU_ENTRY);
   NSString* partialTranslateId = @"chromecommand.menu.partialTranslate";

   __weak __typeof(self) weakSelf = self;
   ProceduralBlockWithBlockWithItemArray provider =
       ^(ProceduralBlockWithItemArray completion) {
         [weakSelf addItemWithCompletion:completion];
       };
   // Use a deferred element so that the item is displayed depending on the text
   // selection and updated on selection change.
   UIDeferredMenuElement* deferredMenuElement =
       [UIDeferredMenuElement elementWithProvider:provider];

   // Translate command is in the lookup menu.
   // Retrieve the menu so it can be replaced with partial translate.
   UIMenu* lookupMenu = [builder menuForIdentifier:UIMenuLookup];
   NSArray* children = lookupMenu.children;
   NSInteger translateIndex = -1;
   for (NSUInteger index = 0; index < children.count; index++) {
     UIMenuElement* element = children[index];
     // Translate is a command.
     if (![element isKindOfClass:[UICommand class]]) {
       continue;
     }
     UICommand* command = base::apple::ObjCCast<UICommand>(element);
     if (command.action != NSSelectorFromString(@"_translate:")) {
       continue;
     }
     translateIndex = index;
     break;
   }

   if (translateIndex == -1) {
     // Translate command not found. Fallback adding the partial translate before
     // the lookup menu.
     // TODO(crbug.com/1417639): Catch this so it can be fixed.
     UIMenu* partialTranslateMenu =
         [UIMenu menuWithTitle:title
                         image:nil
                    identifier:partialTranslateId
                       options:UIMenuOptionsDisplayInline
                      children:@[ deferredMenuElement ]];
     [builder insertSiblingMenu:partialTranslateMenu
         beforeMenuForIdentifier:UIMenuLookup];
     return;
   }

   // Rebuild the lookup menu with partial translate
   NSMutableArray* newChildren = [NSMutableArray arrayWithArray:children];
   newChildren[translateIndex] = deferredMenuElement;
   UIMenu* newPartialTranslate = [UIMenu menuWithTitle:lookupMenu.title
                                                 image:lookupMenu.image
                                            identifier:lookupMenu.identifier
                                               options:lookupMenu.options
                                              children:newChildren];

   [builder replaceMenuForIdentifier:UIMenuLookup withMenu:newPartialTranslate];
 }

 @end
	// Copyright 2023 The Chromium Authors
	// 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/partial_translate/partial_translate_mediator.h"

	#import "base/apple/foundation_util.h"
	#import "base/memory/weak_ptr.h"
	#import "base/metrics/histogram_functions.h"
	#import "components/prefs/pref_member.h"
	#import "components/strings/grit/components_strings.h"
	#import "components/translate/core/browser/translate_pref_names.h"
	#import "ios/chrome/browser/shared/model/web_state_list/web_state_list.h"
	#import "ios/chrome/browser/shared/public/commands/browser_coordinator_commands.h"
	#import "ios/chrome/browser/shared/public/features/features.h"
	#import "ios/chrome/browser/shared/ui/symbols/symbols.h"
	#import "ios/chrome/browser/ui/browser_container/edit_menu_alert_delegate.h"
	#import "ios/chrome/browser/ui/fullscreen/fullscreen_controller.h"
	#import "ios/chrome/browser/web_selection/web_selection_response.h"
	#import "ios/chrome/browser/web_selection/web_selection_tab_helper.h"
	#import "ios/chrome/grit/ios_strings.h"
	#import "ios/public/provider/chrome/browser/partial_translate/partial_translate_api.h"
	#import "ios/web/public/web_state.h"
	#import "ui/base/l10n/l10n_util_mac.h"

	namespace {
	typedef void (^ProceduralBlockWithItemArray)(NSArray<UIMenuElement>);
	typedef void (^ProceduralBlockWithBlockWithItemArray)(
	ProceduralBlockWithItemArray);

	enum class PartialTranslateError {
	kSelectionTooLong,
	kSelectionEmpty,
	kGenericError
	};

	// These values are persisted to logs. Entries should not be renumbered and
	// numeric values should never be reused.
	enum class PartialTranslateOutcomeStatus {
	kSuccess,
	kTooLongCancel,
	kTooLongFullTranslate,
	kEmptyCancel,
	kEmptyFullTranslate,
	kErrorCancel,
	kErrorFullTranslate,
	kMaxValue = kErrorFullTranslate
	};

	void ReportOutcome(PartialTranslateOutcomeStatus outcome) {
	base::UmaHistogramEnumeration("IOS.PartialTranslate.Outcome", outcome);
	}

	void ReportErrorOutcome(PartialTranslateError error, bool went_full) {
	switch (error) {
	case PartialTranslateError::kSelectionTooLong:
	if (went_full) {
	ReportOutcome(PartialTranslateOutcomeStatus::kTooLongFullTranslate);
	} else {
	ReportOutcome(PartialTranslateOutcomeStatus::kTooLongCancel);
	}
	break;
	case PartialTranslateError::kSelectionEmpty:
	if (went_full) {
	ReportOutcome(PartialTranslateOutcomeStatus::kEmptyFullTranslate);
	} else {
	ReportOutcome(PartialTranslateOutcomeStatus::kEmptyCancel);
	}
	break;
	case PartialTranslateError::kGenericError:
	if (went_full) {
	ReportOutcome(PartialTranslateOutcomeStatus::kErrorFullTranslate);
	} else {
	ReportOutcome(PartialTranslateOutcomeStatus::kErrorCancel);
	}
	break;
	}
	}

	// Character limit for the partial translate feature.
	// A string longer than that will trigger a full page translate.
	const NSUInteger kPartialTranslateCharactersLimit = 1000;

	} // anonymous namespace

	@interface PartialTranslateMediator ()

	// Whether the mediator is handling partial translate for an incognito tab.
	@property(nonatomic, weak) UIViewController* baseViewController;

	// Whether the mediator is handling partial translate for an incognito tab.
	@property(nonatomic, assign) BOOL incognito;

	// The controller to display Partial Translate.
	@property(nonatomic, strong) id<PartialTranslateController> controller;

	@end

	@implementation PartialTranslateMediator {
	BooleanPrefMember _translateEnabled;

	// The Browser's WebStateList.
	base::WeakPtr<WebStateList> _webStateList;

	// The fullscreen controller to offset sourceRect depending on fullscreen
	// status.
	FullscreenController* _fullscreenController;
	}

	- (instancetype)initWithWebStateList:(WebStateList*)webStateList
	withBaseViewController:(UIViewController*)baseViewController
	prefService:(PrefService*)prefs
	fullscreenController:(FullscreenController*)fullscreenController
	incognito:(BOOL)incognito {
	if (self = [super init]) {
	DCHECK(webStateList);
	DCHECK(baseViewController);
	_webStateList = webStateList->AsWeakPtr();
	_baseViewController = baseViewController;
	_fullscreenController = fullscreenController;
	_incognito = incognito;
	_translateEnabled.Init(translate::prefs::kOfferTranslateEnabled, prefs);
	}
	return self;
	}

	- (void)shutdown {
	_translateEnabled.Destroy();
	_fullscreenController = nullptr;
	}

	- (void)handlePartialTranslateSelection {
	DCHECK(base::FeatureList::IsEnabled(kIOSEditMenuPartialTranslate));
	WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
	if (!tabHelper) {
	return;
	}

	__weak __typeof(self) weakSelf = self;
	tabHelper->GetSelectedText(base::BindOnce(^(WebSelectionResponse* response) {
	[weakSelf receivedWebSelectionResponse:response];
	}));
	}

	- (BOOL)canHandlePartialTranslateSelection {
	DCHECK(base::FeatureList::IsEnabled(kIOSEditMenuPartialTranslate));
	WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
	if (!tabHelper) {
	return NO;
	}
	return tabHelper->CanRetrieveSelectedText() &&
	ios::provider::PartialTranslateLimitMaxCharacters() > 0u;
	}

	- (BOOL)shouldInstallPartialTranslate {
	if (ios::provider::PartialTranslateLimitMaxCharacters() == 0u) {
	// Feature is not available.
	return NO;
	}
	if (!IsPartialTranslateEnabled()) {
	// Feature is not enabled.
	return NO;
	}
	if (self.incognito && !ShouldShowPartialTranslateInIncognito()) {
	// Feature is enabled, but disabled in incognito, and the current tab is in
	// incognito.
	return NO;
	}
	if (!_translateEnabled.GetValue() && _translateEnabled.IsManaged()) {
	// Translate is a managed settings and disabled.
	return NO;
	}
	return YES;
	}

	- (void)switchToFullTranslateWithError:(PartialTranslateError)error {
	if (!self.alertDelegate) {
	return;
	}
	NSString* message;
	switch (error) {
	case PartialTranslateError::kSelectionTooLong:
	message = l10n_util::GetNSString(
	IDS_IOS_PARTIAL_TRANSLATE_ERROR_STRING_TOO_LONG_ERROR);
	break;
	case PartialTranslateError::kSelectionEmpty:
	message =
	l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_ERROR_STRING_EMPTY);
	break;
	case PartialTranslateError::kGenericError:
	message = l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_ERROR_GENERIC);
	break;
	}
	DCHECK(message);
	__weak __typeof(self) weakSelf = self;
	EditMenuAlertDelegateAction* cancelAction =
	[[EditMenuAlertDelegateAction alloc]
	initWithTitle:l10n_util::GetNSString(IDS_CANCEL)
	action:^{
	ReportErrorOutcome(error, false);
	}
	style:UIAlertActionStyleCancel
	preferred:NO];
	EditMenuAlertDelegateAction* translateAction = [[EditMenuAlertDelegateAction
	alloc]
	initWithTitle:l10n_util::GetNSString(
	IDS_IOS_PARTIAL_TRANSLATE_ACTION_TRANSLATE_FULL_PAGE)
	action:^{
	ReportErrorOutcome(error, true);
	[weakSelf triggerFullTranslate];
	}
	style:UIAlertActionStyleDefault
	preferred:YES];

	[self.alertDelegate
	showAlertWithTitle:
	l10n_util::GetNSString(
	IDS_IOS_PARTIAL_TRANSLATE_SWITCH_FULL_PAGE_TRANSLATION)
	message:message
	actions:@[ cancelAction, translateAction ]];
	}

	- (void)receivedWebSelectionResponse:(WebSelectionResponse*)response {
	DCHECK(response);
	base::UmaHistogramCounts10000("IOS.PartialTranslate.SelectionLength",
	response.selectedText.length);
	if (response.selectedText.length >
	std::min(ios::provider::PartialTranslateLimitMaxCharacters(),
	kPartialTranslateCharactersLimit)) {
	return [self switchToFullTranslateWithError:PartialTranslateError::
	kSelectionTooLong];
	}
	if (!response.valid \|\|
	[[response.selectedText
	stringByTrimmingCharactersInSet:[NSCharacterSet
	whitespaceAndNewlineCharacterSet]]
	length] == 0u) {
	return [self
	switchToFullTranslateWithError:PartialTranslateError::kSelectionEmpty];
	}

	CGRect sourceRect = response.sourceRect;
	if (_fullscreenController && !CGRectEqualToRect(sourceRect, CGRectZero)) {
	UIEdgeInsets fullscreenInset =
	_fullscreenController->GetCurrentViewportInsets();
	sourceRect.origin.y += fullscreenInset.top;
	sourceRect.origin.x += fullscreenInset.left;
	}

	self.controller = ios::provider::NewPartialTranslateController(
	response.selectedText, sourceRect, self.incognito);
	__weak __typeof(self) weakSelf = self;
	[self.controller presentOnViewController:self.baseViewController
	flowCompletionHandler:^(BOOL success) {
	weakSelf.controller = nil;
	if (success) {
	ReportOutcome(PartialTranslateOutcomeStatus::kSuccess);
	} else {
	[weakSelf switchToFullTranslateWithError:
	PartialTranslateError::kGenericError];
	}
	}];
	}

	- (void)triggerFullTranslate {
	[self.browserHandler showTranslate];
	}

	- (WebSelectionTabHelper*)webSelectionTabHelper {
	web::WebState* webState =
	_webStateList ? _webStateList->GetActiveWebState() : nullptr;
	if (!webState) {
	return nullptr;
	}
	WebSelectionTabHelper* helper = WebSelectionTabHelper::FromWebState(webState);
	return helper;
	}

	- (void)addItemWithCompletion:(ProceduralBlockWithItemArray)completion {
	if (![self canHandlePartialTranslateSelection]) {
	completion(@[]);
	return;
	}
	WebSelectionTabHelper* tabHelper = [self webSelectionTabHelper];
	if (!tabHelper) {
	completion(@[]);
	return;
	}

	__weak __typeof(self) weakSelf = self;
	tabHelper->GetSelectedText(base::BindOnce(^(WebSelectionResponse* response) {
	if (weakSelf) {
	[weakSelf addItemWithResponse:response completion:completion];
	} else {
	completion(@[]);
	}
	}));
	}

	- (void)addItemWithResponse:(WebSelectionResponse*)response
	completion:(ProceduralBlockWithItemArray)completion {
	__weak __typeof(self) weakSelf = self;
	if (!response.valid \|\|
	[[response.selectedText
	stringByTrimmingCharactersInSet:[NSCharacterSet
	whitespaceAndNewlineCharacterSet]]
	length] == 0u) {
	completion(@[]);
	return;
	}
	NSString* title =
	l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_EDIT_MENU_ENTRY);
	NSString* partialTranslateId = @"chromecommand.partialTranslate";
	UIAction* action =
	[UIAction actionWithTitle:title
	image:CustomSymbolWithPointSize(
	kTranslateSymbol, kSymbolActionPointSize)
	identifier:partialTranslateId
	handler:^(UIAction* a) {
	[weakSelf receivedWebSelectionResponse:response];
	}];
	completion(@[ action ]);
	}

	#pragma mark - EditMenuProvider

	- (void)buildMenuWithBuilder:(id<UIMenuBuilder>)builder {
	if (![self shouldInstallPartialTranslate]) {
	return;
	}
	NSString* title =
	l10n_util::GetNSString(IDS_IOS_PARTIAL_TRANSLATE_EDIT_MENU_ENTRY);
	NSString* partialTranslateId = @"chromecommand.menu.partialTranslate";

	__weak __typeof(self) weakSelf = self;
	ProceduralBlockWithBlockWithItemArray provider =
	^(ProceduralBlockWithItemArray completion) {
	[weakSelf addItemWithCompletion:completion];
	};
	// Use a deferred element so that the item is displayed depending on the text
	// selection and updated on selection change.
	UIDeferredMenuElement* deferredMenuElement =
	[UIDeferredMenuElement elementWithProvider:provider];

	// Translate command is in the lookup menu.
	// Retrieve the menu so it can be replaced with partial translate.
	UIMenu* lookupMenu = [builder menuForIdentifier:UIMenuLookup];
	NSArray* children = lookupMenu.children;
	NSInteger translateIndex = -1;
	for (NSUInteger index = 0; index < children.count; index++) {
	UIMenuElement* element = children[index];
	// Translate is a command.
	if (![element isKindOfClass:[UICommand class]]) {
	continue;
	}
	UICommand* command = base::apple::ObjCCast<UICommand>(element);
	if (command.action != NSSelectorFromString(@"_translate:")) {
	continue;
	}
	translateIndex = index;
	break;
	}

	if (translateIndex == -1) {
	// Translate command not found. Fallback adding the partial translate before
	// the lookup menu.
	// TODO(crbug.com/1417639): Catch this so it can be fixed.
	UIMenu* partialTranslateMenu =
	[UIMenu menuWithTitle:title
	image:nil
	identifier:partialTranslateId
	options:UIMenuOptionsDisplayInline
	children:@[ deferredMenuElement ]];
	[builder insertSiblingMenu:partialTranslateMenu
	beforeMenuForIdentifier:UIMenuLookup];
	return;
	}

	// Rebuild the lookup menu with partial translate
	NSMutableArray* newChildren = [NSMutableArray arrayWithArray:children];
	newChildren[translateIndex] = deferredMenuElement;
	UIMenu* newPartialTranslate = [UIMenu menuWithTitle:lookupMenu.title
	image:lookupMenu.image
	identifier:lookupMenu.identifier
	options:lookupMenu.options
	children:newChildren];

	[builder replaceMenuForIdentifier:UIMenuLookup withMenu:newPartialTranslate];
	}

	@end