[Payment Request] Refactors the remaining selector view controllers

ios/chrome/browser/payments/shipping_option_selection_coordinator.mm

 // Copyright 2017 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/payments/shipping_option_selection_coordinator.h"
 
+#include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
+#include "components/payments/core/strings_util.h"
 #include "ios/chrome/browser/payments/payment_request.h"
 #import "ios/chrome/browser/payments/payment_request_util.h"
+#include "ios/chrome/browser/payments/shipping_option_selection_mediator.h"
 #include "ios/web/public/payments/payment_request.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 using ::payment_request_util::GetShippingOptionSelectorErrorMessage;
+using ::payments::GetShippingOptionSectionString;
 }  // namespace
 
 @interface ShippingOptionSelectionCoordinator ()
 
 @property(nonatomic, strong)
-    ShippingOptionSelectionViewController* viewController;
+    PaymentRequestSelectorViewController* viewController;
+
+@property(nonatomic, strong) ShippingOptionSelectionMediator* mediator;
 
 // Called when the user selects a shipping option. The cell is checked, the
 // UI is locked so that the user can't interact with it, then the delegate is
 // notified. The delay is here to let the user get a visual feedback of the
 // selection before this view disappears.
 - (void)delayedNotifyDelegateOfSelection:
     (web::PaymentShippingOption*)shippingOption;
 
 @end
 
 @implementation ShippingOptionSelectionCoordinator
 
 @synthesize paymentRequest = _paymentRequest;
 @synthesize delegate = _delegate;
 @synthesize viewController = _viewController;
+@synthesize mediator = _mediator;
 
 - (void)start {
-  _viewController = [[ShippingOptionSelectionViewController alloc]
-      initWithPaymentRequest:_paymentRequest];
-  [_viewController setDelegate:self];
-  [_viewController loadModel];
+  self.mediator = [[ShippingOptionSelectionMediator alloc]
+      initWithPaymentRequest:self.paymentRequest];
+
+  self.viewController = [[PaymentRequestSelectorViewController alloc] init];
+  self.viewController.title = base::SysUTF16ToNSString(
+      GetShippingOptionSectionString(self.paymentRequest->shipping_type()));
+  self.viewController.delegate = self;
+  self.viewController.dataSource = self.mediator;
+  [self.viewController loadModel];
 
   DCHECK(self.baseViewController.navigationController);
   [self.baseViewController.navigationController
-      pushViewController:_viewController
+      pushViewController:self.viewController
                 animated:YES];
 }
 
 - (void)stop {
   [self.baseViewController.navigationController popViewControllerAnimated:YES];
-  _viewController = nil;
+  self.viewController = nil;
+  self.mediator = nil;
 }
 
 - (void)stopSpinnerAndDisplayError {
   // Re-enable user interactions that were disabled earlier in
   // delayedNotifyDelegateOfSelection.
-  _viewController.view.userInteractionEnabled = YES;
+  self.viewController.view.userInteractionEnabled = YES;
 
-  [_viewController setPending:NO];
-  DCHECK(_paymentRequest);
-  [_viewController
-      setErrorMessage:GetShippingOptionSelectorErrorMessage(*_paymentRequest)];
-  [_viewController loadModel];
-  [[_viewController collectionView] reloadData];
+  DCHECK(self.paymentRequest);
+  self.mediator.headerText =
+      GetShippingOptionSelectorErrorMessage(*self.paymentRequest);
+  self.mediator.state = PaymentRequestSelectorStateError;
+  [self.viewController loadModel];
+  [self.viewController.collectionView reloadData];
 }
 
-#pragma mark - ShippingOptionSelectionViewControllerDelegate
+#pragma mark - PaymentRequestSelectorViewControllerDelegate
 
-- (void)shippingOptionSelectionViewController:
-            (ShippingOptionSelectionViewController*)controller
-                      didSelectShippingOption:
-                          (web::PaymentShippingOption*)shippingOption {
-  [self delayedNotifyDelegateOfSelection:shippingOption];
+- (void)paymentRequestSelectorViewController:
+            (PaymentRequestSelectorViewController*)controller
+                        didSelectItemAtIndex:(NSUInteger)index {
+  // Update the data source with the selection.
+  self.mediator.selectedItemIndex = index;
+
+  DCHECK(index < self.paymentRequest->shipping_options().size());
+  [self delayedNotifyDelegateOfSelection:self.paymentRequest
+                                             ->shipping_options()[index]];
 }
 
-- (void)shippingOptionSelectionViewControllerDidReturn:
-    (ShippingOptionSelectionViewController*)controller {
-  [_delegate shippingOptionSelectionCoordinatorDidReturn:self];
+- (void)paymentRequestSelectorViewControllerDidFinish:
+    (PaymentRequestSelectorViewController*)controller {
+  [self.delegate shippingOptionSelectionCoordinatorDidReturn:self];
 }
 
+- (void)paymentRequestSelectorViewControllerDidSelectAddItem:
+    (PaymentRequestSelectorViewController*)controller {
+  NOTREACHED() << "This should not get called.";

[macourteau, 2017/04/19 18:03:13]

What about moving this into the base class, and not override it if it's not
supported?

[Moe, 2017/04/19 20:12:44]

There's no base class to move this to. Any coordinator that implements the
PaymentRequestSelectorViewControllerDelegate protocol needs to handle all the
methods. PaymentRequestSelectorViewController is a generic view controller that
does provide an optional "Add" button and this is its respective delegate
function. But since this coordinator doesn't set up the view controller to have
an "Add" button, this function should never gets called.

[macourteau, 2017/04/20 14:42:59]

TIL about protocols in Objective-C. :)

n00b question: can this method be in an @optional section in the protocol, and
then use respondsToSelector: to figure out if it supports an Add item?

[Moe, 2017/04/20 15:23:30]

Good idea! TIL too!

+}
+
+#pragma mark - Helper methods
+
 - (void)delayedNotifyDelegateOfSelection:
     (web::PaymentShippingOption*)shippingOption {
-  _viewController.view.userInteractionEnabled = NO;
+  self.viewController.view.userInteractionEnabled = NO;
   __weak ShippingOptionSelectionCoordinator* weakSelf = self;
-  dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
-                               static_cast<int64_t>(0.2 * NSEC_PER_SEC)),
-                 dispatch_get_main_queue(), ^{
-                   ShippingOptionSelectionCoordinator* strongSelf = weakSelf;
-                   // Early return if the coordinator has been deallocated.
-                   if (!strongSelf)
-                     return;
-                   [strongSelf.viewController setPending:YES];
-                   [strongSelf.viewController loadModel];
-                   [[strongSelf.viewController collectionView] reloadData];
+  dispatch_after(
+      dispatch_time(DISPATCH_TIME_NOW,
+                    static_cast<int64_t>(0.2 * NSEC_PER_SEC)),
+      dispatch_get_main_queue(), ^{
+        [weakSelf.mediator setState:PaymentRequestSelectorStatePending];
+        [weakSelf.viewController loadModel];
+        [weakSelf.viewController.collectionView reloadData];
 
-                   [strongSelf.delegate
-                       shippingOptionSelectionCoordinator:strongSelf
-                                  didSelectShippingOption:shippingOption];
-                 });
+        [weakSelf.delegate shippingOptionSelectionCoordinator:weakSelf
+                                      didSelectShippingOption:shippingOption];
+      });
 }
 
 @end