[iOS] Add Scoping to QR Code Generator Coordinator

By adding a scopedHandler to handle both the "Show QR Code" and
"Dismiss QR Code" commands, we'll be able to reuse the ActivityServices
component to share URLs outside from the BrowserCoordinator.

Bug: 1102890
Change-Id: I830b3ed7a1a44cc1e4242c666bc3427d05aaf471
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2284101
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#790840}

ios/chrome/browser/ui/activity_services/activities/generate_qr_code_activity.mm

@@ -57,7 +57,7 @@ NSString* const kGenerateQrCodeActivityType =
 }
 
 - (BOOL)canPerformWithActivityItems:(NSArray*)activityItems {
-  return base::FeatureList::IsEnabled(kQRCodeGeneration);
+  return base::FeatureList::IsEnabled(kQRCodeGeneration) && self.handler;
 }
 
 + (UIActivityCategory)activityCategory {

ios/chrome/browser/ui/activity_services/activities/generate_qr_code_activity_unittest.mm

@@ -56,6 +56,17 @@ TEST_F(GenerateQrCodeActivityTest, FlagOff_ActivityDisabled) {
   EXPECT_FALSE([activity canPerformWithActivityItems:@[]]);
 }
 
+// Tests that the activity cannot be performed when its handler is nil.
+TEST_F(GenerateQrCodeActivityTest, NilHandler_ActivityDisabled) {
+  scoped_features_.InitAndEnableFeature(kQRCodeGeneration);
+  GenerateQrCodeActivity* activity =
+      [[GenerateQrCodeActivity alloc] initWithURL:GURL("https://example.com")
+                                            title:@"Some title"
+                                          handler:nil];
+
+  EXPECT_FALSE([activity canPerformWithActivityItems:@[]]);
+}
+
 // Tests that the right handler method is invoked upon execution.
 TEST_F(GenerateQrCodeActivityTest, Execution) {
   __block GURL fakeURL("https://example.com");

ios/chrome/browser/ui/activity_services/activity_service_coordinator.h

@@ -11,6 +11,7 @@
 @protocol ActivityServicePositioner;
 @protocol ActivityServicePresentation;
 class Browser;
+@protocol QRGenerationCommands;
 
 // ActivityServiceCoordinator provides a public interface for the share
 // menu feature.
@@ -39,6 +40,9 @@ class Browser;
 @property(nonatomic, readwrite, weak) id<ActivityServicePresentation>
     presentationProvider;
 
+// Handler for activities that need to be executed within a certain scope.
+@property(nonatomic, weak) id<QRGenerationCommands> scopedHandler;
+
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_ACTIVITY_SERVICE_COORDINATOR_H_

ios/chrome/browser/ui/activity_services/activity_service_coordinator.mm

@@ -38,9 +38,7 @@ const char kSharePageLatencyHistogram[] = "IOS.SharePageLatency";
 
 @interface ActivityServiceCoordinator ()
 
-@property(nonatomic, weak)
-    id<BrowserCommands, FindInPageCommands, QRGenerationCommands>
-        handler;
+@property(nonatomic, weak) id<BrowserCommands, FindInPageCommands> handler;
 
 // The time when the Share Page operation started.
 @property(nonatomic, assign) base::TimeTicks sharePageStartTime;
@@ -69,8 +67,7 @@ const char kSharePageLatencyHistogram[] = "IOS.SharePageLatency";
 #pragma mark - Public methods
 
 - (void)start {
-  self.handler = static_cast<
-      id<BrowserCommands, FindInPageCommands, QRGenerationCommands>>(
+  self.handler = static_cast<id<BrowserCommands, FindInPageCommands>>(
       self.browser->GetCommandDispatcher());
 
   ChromeBrowserState* browserState = self.browser->GetBrowserState();
@@ -78,6 +75,7 @@ const char kSharePageLatencyHistogram[] = "IOS.SharePageLatency";
       ios::BookmarkModelFactory::GetForBrowserState(browserState);
   self.mediator =
       [[ActivityServiceMediator alloc] initWithHandler:self.handler
+                                   qrGenerationHandler:self.scopedHandler
                                            prefService:browserState->GetPrefs()
                                          bookmarkModel:bookmarkModel];
 

ios/chrome/browser/ui/activity_services/activity_service_mediator.h

@@ -28,13 +28,13 @@ class PrefService;
 @interface ActivityServiceMediator : NSObject
 
 // Initializes a mediator instance with a |handler| used to execute action, a
-// |prefService| to read settings and policies, and a |bookmarkModel| to
-// retrieve bookmark states.
-- (instancetype)
-    initWithHandler:
-        (id<BrowserCommands, FindInPageCommands, QRGenerationCommands>)handler
-        prefService:(PrefService*)prefService
-      bookmarkModel:(bookmarks::BookmarkModel*)bookmarkModel
+// |qrGenerationHandler| to execute QR generation actions, a |prefService| to
+// read settings and policies, and a |bookmarkModel| to retrieve bookmark
+// states.
+- (instancetype)initWithHandler:(id<BrowserCommands, FindInPageCommands>)handler
+            qrGenerationHandler:(id<QRGenerationCommands>)qrGenerationHandler
+                    prefService:(PrefService*)prefService
+                  bookmarkModel:(bookmarks::BookmarkModel*)bookmarkModel
     NS_DESIGNATED_INITIALIZER;
 - (instancetype)init NS_UNAVAILABLE;
 

ios/chrome/browser/ui/activity_services/activity_service_mediator.mm

@@ -39,9 +39,9 @@
 
 @interface ActivityServiceMediator ()
 
-@property(nonatomic, weak)
-    id<BrowserCommands, FindInPageCommands, QRGenerationCommands>
-        handler;
+@property(nonatomic, weak) id<BrowserCommands, FindInPageCommands> handler;
+
+@property(nonatomic, weak) id<QRGenerationCommands> qrGenerationHandler;
 
 @property(nonatomic, assign) PrefService* prefService;
 
@@ -53,13 +53,13 @@
 
 #pragma mark - Public
 
-- (instancetype)
-    initWithHandler:
-        (id<BrowserCommands, FindInPageCommands, QRGenerationCommands>)handler
-        prefService:(PrefService*)prefService
-      bookmarkModel:(bookmarks::BookmarkModel*)bookmarkModel {
+- (instancetype)initWithHandler:(id<BrowserCommands, FindInPageCommands>)handler
+            qrGenerationHandler:(id<QRGenerationCommands>)qrGenerationHandler
+                    prefService:(PrefService*)prefService
+                  bookmarkModel:(bookmarks::BookmarkModel*)bookmarkModel {
   if (self = [super init]) {
     _handler = handler;
+    _qrGenerationHandler = qrGenerationHandler;
     _prefService = prefService;
     _bookmarkModel = bookmarkModel;
   }
@@ -103,7 +103,7 @@
     GenerateQrCodeActivity* generateQrCodeActivity =
         [[GenerateQrCodeActivity alloc] initWithURL:data.shareURL
                                               title:data.title
-                                            handler:self.handler];
+                                            handler:self.qrGenerationHandler];
     [applicationActivities addObject:generateQrCodeActivity];
 
     FindInPageActivity* findInPageActivity =

ios/chrome/browser/ui/activity_services/activity_service_mediator_unittest.mm

@@ -35,8 +35,7 @@
 #error "This file requires ARC support."
 #endif
 
-@protocol
-    HandlerProtocols <BrowserCommands, FindInPageCommands, QRGenerationCommands>
+@protocol HandlerProtocols <BrowserCommands, FindInPageCommands>
 @end
 
 class ActivityServiceMediatorTest : public PlatformTest {
@@ -47,13 +46,16 @@ class ActivityServiceMediatorTest : public PlatformTest {
     pref_service_ = std::make_unique<TestingPrefServiceSimple>();
 
     mocked_handler_ = OCMStrictProtocolMock(@protocol(HandlerProtocols));
+    mocked_qr_generation_handler_ =
+        OCMStrictProtocolMock(@protocol(QRGenerationCommands));
     mocked_thumbnail_generator_ =
         OCMStrictClassMock([ChromeActivityItemThumbnailGenerator class]);
 
-    mediator_ =
-        [[ActivityServiceMediator alloc] initWithHandler:mocked_handler_
-                                             prefService:pref_service_.get()
-                                           bookmarkModel:nil];
+    mediator_ = [[ActivityServiceMediator alloc]
+            initWithHandler:mocked_handler_
+        qrGenerationHandler:mocked_qr_generation_handler_
+                prefService:pref_service_.get()
+              bookmarkModel:nil];
   }
 
   void VerifyTypes(NSArray* activities, NSArray* expected_types) {
@@ -64,6 +66,7 @@ class ActivityServiceMediatorTest : public PlatformTest {
   }
 
   id mocked_handler_;
+  id mocked_qr_generation_handler_;
   id mocked_thumbnail_generator_;
   std::unique_ptr<TestingPrefServiceSimple> pref_service_;
   base::HistogramTester histograms_tester_;

ios/chrome/browser/ui/browser_view/browser_coordinator.mm

@@ -233,8 +233,6 @@
                    forProtocol:@protocol(BrowserCoordinatorCommands)];
   [self.dispatcher startDispatchingToTarget:self
                                 forProtocol:@protocol(PageInfoCommands)];
-  [self.dispatcher startDispatchingToTarget:self
-                                forProtocol:@protocol(QRGenerationCommands)];
   [self installDelegatesForAllWebStates];
   [self installDelegatesForBrowser];
   [self addWebStateListObserver];
@@ -526,9 +524,12 @@
       initWithBaseViewController:self.viewController
                          browser:self.browser
                         scenario:ActivityScenario::TabShareButton];
+
   self.activityServiceCoordinator.positionProvider =
       [self.viewController activityServicePositioner];
   self.activityServiceCoordinator.presentationProvider = self;
+  self.activityServiceCoordinator.scopedHandler = self;
+
   [self.activityServiceCoordinator start];
 }
 
@@ -750,7 +751,8 @@
       initWithBaseViewController:self.viewController
                          browser:self.browser
                            title:command.title
-                             URL:command.URL];
+                             URL:command.URL
+                         handler:self];
   [self.qrGeneratorCoordinator start];
 }
 

ios/chrome/browser/ui/qr_generator/qr_generator_coordinator.h

@@ -8,16 +8,20 @@
 #import "ios/chrome/browser/ui/coordinators/chrome_coordinator.h"
 #include "url/gurl.h"
 
+@protocol QRGenerationCommands;
+
 // QRGeneratorCoordinator presents the public interface for the QR code
 // generation feature.
 @interface QRGeneratorCoordinator : ChromeCoordinator
 
 // Initializes an instance with a base |viewController|, the current |browser|,
-// the |title| and |URL| of a webpage to generate a QR code for.
+// the |title| and |URL| of a webpage to generate a QR code for, and a |handler|
+// to handle commands execution.
 - (instancetype)initWithBaseViewController:(UIViewController*)viewController
                                    browser:(Browser*)browser
                                      title:(NSString*)title
                                        URL:(const GURL&)URL
+                                   handler:(id<QRGenerationCommands>)handler
     NS_DESIGNATED_INITIALIZER;
 
 // Unavailable, use -initWithBaseViewController:browser:title:URL:.

ios/chrome/browser/ui/qr_generator/qr_generator_coordinator.mm

@@ -58,11 +58,13 @@
 - (instancetype)initWithBaseViewController:(UIViewController*)viewController
                                    browser:(Browser*)browser
                                      title:(NSString*)title
-                                       URL:(const GURL&)URL {
+                                       URL:(const GURL&)URL
+                                   handler:(id<QRGenerationCommands>)handler {
   if (self = [super initWithBaseViewController:viewController
                                        browser:browser]) {
     _title = title;
     _URL = URL;
+    _handler = handler;
   }
   return self;
 }
@@ -70,9 +72,6 @@
 #pragma mark - Chrome Coordinator
 
 - (void)start {
-  self.handler = HandlerForProtocol(self.browser->GetCommandDispatcher(),
-                                    QRGenerationCommands);
-
   self.viewController = [[QRGeneratorViewController alloc] init];
 
   [self.viewController setModalPresentationStyle:UIModalPresentationFormSheet];

ios/chrome/browser/ui/qr_generator/qr_generator_coordinator_unittest.mm

@@ -35,17 +35,15 @@ class QRGeneratorCoordinatorTest : public PlatformTest {
     mock_qr_generation_commands_handler_ =
         OCMStrictProtocolMock(@protocol(QRGenerationCommands));
 
-    [browser_->GetCommandDispatcher()
-        startDispatchingToTarget:mock_qr_generation_commands_handler_
-                     forProtocol:@protocol(QRGenerationCommands)];
-
     test_title_ = @"Does not matter";
 
     coordinator_ = [[QRGeneratorCoordinator alloc]
         initWithBaseViewController:base_view_controller_
                            browser:browser_.get()
                              title:test_title_
-                               URL:test_url_];
+                               URL:test_url_
+                           handler:(id<QRGenerationCommands>)
+                                       mock_qr_generation_commands_handler_];
   }
 
   NSString* test_title_;