[iOS] Add "Learn More" Button to QR Code View

UX-requested functionality which allows users to learn more about what
they can do with a QR code. When tapping on the "Learn More" button, a
popover is shown with the help text.

Bug: 1064990
Change-Id: I1cc65f29607089e95c766c518fe0af526061aeb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2218705Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773194}

ios/chrome/app/strings/ios_strings.grd

@@ -1339,6 +1339,9 @@ Handoff must also be enabled in the General section of Settings, and your device
       <message name="IDS_IOS_QR_CODE_ACTIVITY_TITLE" desc="Title format of the share view shown when sharing a QR code generated for a given Web page. [iOS only]">
         QR Code: <ph name="PAGE_TITLE">$1</ph>
       </message>
+      <message name="IDS_IOS_QR_CODE_LEARN_MORE_MESSAGE" desc="Message explaining what users can do with a generated QR code. [iOS only]">
+        To share with people nearby, let them scan this QR code with their camera or QR scanner app
+      </message>
       <message name="IDS_IOS_QR_SCANNER_ALERT_CANCEL" desc="Title for a button to cancel a QR Scanner error dialog. The dialog will be dismissed and no action will be taken. [Length: 20em] [iOS only]" meaning="A button to cancel a QR Scanner error dialog.">
         Cancel
       </message>

ios/chrome/app/strings/ios_strings_grd/IDS_IOS_QR_CODE_LEARN_MORE_MESSAGE.png.sha1

+b8da944a5ebce897c74aeb3d4f95d3ff2205398a
\ No newline at end of file

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

@@ -42,6 +42,7 @@ source_set("qr_generator") {
     "//ios/chrome/browser/ui/commands",
     "//ios/chrome/browser/ui/coordinators:chrome_coordinators",
     "//ios/chrome/common/ui/confirmation_alert",
+    "//ios/chrome/common/ui/elements:popover_label_view_controller",
     "//net",
     "//ui/base",
   ]
@@ -62,6 +63,7 @@ source_set("unit_tests") {
     "//ios/chrome/browser/main:test_support",
     "//ios/chrome/browser/ui/commands",
     "//ios/chrome/common/ui/confirmation_alert",
+    "//ios/chrome/common/ui/elements:popover_label_view_controller",
     "//ios/chrome/test:test_support",
     "//ios/chrome/test/fakes",
     "//ios/web",

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

@@ -16,6 +16,7 @@
 #import "ios/chrome/browser/ui/commands/qr_generation_commands.h"
 #import "ios/chrome/browser/ui/qr_generator/qr_generator_view_controller.h"
 #import "ios/chrome/common/ui/confirmation_alert/confirmation_alert_action_handler.h"
+#import "ios/chrome/common/ui/elements/popover_label_view_controller.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "net/base/mac/url_conversions.h"
 #include "ui/base/l10n/l10n_util_mac.h"
@@ -45,6 +46,10 @@
 // Title of a page to generate a QR code for.
 @property(nonatomic, copy) NSString* title;
 
+// Popover used to show learn more info, not nil when presented.
+@property(nonatomic, strong)
+    PopoverLabelViewController* learnMoreViewController;
+
 @end
 
 @implementation QRGeneratorCoordinator
@@ -73,6 +78,7 @@
   [self.viewController setPageURL:net::NSURLWithGURL(_URL)];
   [self.viewController setTitleString:self.title];
   [self.viewController setActionHandler:self];
+  [self.viewController setHelpButtonAvailable:YES];
 
   [self.baseViewController presentViewController:self.viewController
                                         animated:YES
@@ -83,6 +89,7 @@
 - (void)stop {
   [self.viewController dismissViewControllerAnimated:YES completion:nil];
   self.viewController = nil;
+  self.learnMoreViewController = nil;
 
   [self.activityServiceCoordinator stop];
   self.activityServiceCoordinator = nil;
@@ -115,8 +122,19 @@
 }
 
 - (void)confirmationAlertLearnMoreAction {
-  // No-op.
-  // TODO crbug.com/1064990: Add learn more behavior.
+  NSString* message =
+      l10n_util::GetNSString(IDS_IOS_QR_CODE_LEARN_MORE_MESSAGE);
+  self.learnMoreViewController =
+      [[PopoverLabelViewController alloc] initWithMessage:message];
+
+  self.learnMoreViewController.popoverPresentationController.barButtonItem =
+      self.viewController.helpButton;
+  self.learnMoreViewController.popoverPresentationController
+      .permittedArrowDirections = UIPopoverArrowDirectionUp;
+
+  [self.viewController presentViewController:self.learnMoreViewController
+                                    animated:YES
+                                  completion:nil];
 }
 
 #pragma mark - ActivityServicePositioner

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

@@ -11,7 +11,9 @@
 #import "ios/chrome/browser/ui/commands/qr_generation_commands.h"
 #import "ios/chrome/browser/ui/qr_generator/qr_generator_view_controller.h"
 #import "ios/chrome/common/ui/confirmation_alert/confirmation_alert_action_handler.h"
+#import "ios/chrome/common/ui/elements/popover_label_view_controller.h"
 #import "ios/chrome/test/scoped_key_window.h"
+#import "net/base/mac/url_conversions.h"
 #include "testing/platform_test.h"
 #import "third_party/ocmock/OCMock/OCMock.h"
 #include "url/gurl.h"
@@ -22,7 +24,9 @@
 
 class QRGeneratorCoordinatorTest : public PlatformTest {
  protected:
-  QRGeneratorCoordinatorTest() : browser_(std::make_unique<TestBrowser>()) {
+  QRGeneratorCoordinatorTest()
+      : test_url_("https://www.google.com/"),
+        browser_(std::make_unique<TestBrowser>()) {
     base_view_controller_ = [[UIViewController alloc] init];
     [scoped_key_window_.Get() setRootViewController:base_view_controller_];
   }
@@ -34,13 +38,26 @@ class QRGeneratorCoordinatorTest : public PlatformTest {
     [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_];
   }
 
+  NSString* test_title_;
+  GURL test_url_;
+
   base::test::TaskEnvironment task_environment_;
   id mock_qr_generation_commands_handler_;
   std::unique_ptr<TestBrowser> browser_;
   ScopedKeyWindow scoped_key_window_;
   UIViewController* base_view_controller_;
+
+  QRGeneratorCoordinator* coordinator_;
 };
 
 // Tests that a Done button gets added to the navigation bar, and its action
@@ -49,17 +66,11 @@ TEST_F(QRGeneratorCoordinatorTest, Done_DispatchesCommand) {
   // Set-up mocked handler.
   [[mock_qr_generation_commands_handler_ expect] hideQRCode];
 
-  // Create and start coordinator.
-  QRGeneratorCoordinator* coordinator = [[QRGeneratorCoordinator alloc]
-      initWithBaseViewController:base_view_controller_
-                         browser:browser_.get()
-                           title:@"Does not matter"
-                             URL:GURL()];
-
-  ASSERT_EQ(base_view_controller_, coordinator.baseViewController);
+  // Check and start coordinator.
+  ASSERT_EQ(base_view_controller_, coordinator_.baseViewController);
   ASSERT_FALSE(base_view_controller_.presentedViewController);
 
-  [coordinator start];
+  [coordinator_ start];
 
   ASSERT_TRUE(base_view_controller_.presentedViewController);
   ASSERT_TRUE([base_view_controller_.presentedViewController
@@ -69,9 +80,75 @@ TEST_F(QRGeneratorCoordinatorTest, Done_DispatchesCommand) {
       base::mac::ObjCCastStrict<QRGeneratorViewController>(
           base_view_controller_.presentedViewController);
 
+  // Verify some properties on the VC.
+  EXPECT_TRUE(viewController.helpButtonAvailable);
+  EXPECT_EQ(test_title_, viewController.titleString);
+  EXPECT_TRUE([net::NSURLWithGURL(test_url_) isEqual:viewController.pageURL]);
+
   // Mimick click on done button.
   [viewController.actionHandler confirmationAlertDone];
 
   // Callback should've gotten invoked.
   [mock_qr_generation_commands_handler_ verify];
 }
+
+// Tests that tje primary action, share, intializes the activity service
+// coordinator properly.
+TEST_F(QRGeneratorCoordinatorTest, ShareAction) {
+  [coordinator_ start];
+
+  QRGeneratorViewController* viewController =
+      base::mac::ObjCCastStrict<QRGeneratorViewController>(
+          base_view_controller_.presentedViewController);
+
+  id vcPartialMock = OCMPartialMock(viewController);
+  [[vcPartialMock expect]
+      presentViewController:[OCMArg checkWithBlock:^BOOL(
+                                        UIViewController* givenVC) {
+        return [givenVC isKindOfClass:[UIActivityViewController class]];
+      }]
+                   animated:YES
+                 completion:nil];
+
+  // Mimic tap on share button.
+  [viewController.actionHandler confirmationAlertPrimaryAction];
+
+  [vcPartialMock verify];
+}
+
+// Tests that a popover is properly created and shown when the user taps on
+// the learn more button.
+TEST_F(QRGeneratorCoordinatorTest, LearnMore) {
+  [coordinator_ start];
+
+  QRGeneratorViewController* viewController =
+      base::mac::ObjCCastStrict<QRGeneratorViewController>(
+          base_view_controller_.presentedViewController);
+
+  __block PopoverLabelViewController* popoverViewController;
+  id vcPartialMock = OCMPartialMock(viewController);
+  [[vcPartialMock expect]
+      presentViewController:[OCMArg checkWithBlock:^BOOL(
+                                        UIViewController* givenVC) {
+        if ([givenVC isKindOfClass:[PopoverLabelViewController class]]) {
+          popoverViewController =
+              base::mac::ObjCCastStrict<PopoverLabelViewController>(givenVC);
+          return YES;
+        }
+        return NO;
+      }]
+                   animated:YES
+                 completion:nil];
+
+  // Mimic tap on help button.
+  [viewController.actionHandler confirmationAlertLearnMoreAction];
+
+  [vcPartialMock verify];
+  EXPECT_TRUE(popoverViewController);
+
+  EXPECT_EQ(viewController.helpButton,
+            popoverViewController.popoverPresentationController.barButtonItem);
+  EXPECT_EQ(UIPopoverArrowDirectionUp,
+            popoverViewController.popoverPresentationController
+                .permittedArrowDirections);
+}