[Payment Request] Selector view controller

ios/chrome/browser/payments/payment_request_selector_view_controller.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/payment_request_selector_view_controller.h"
+
+#include "base/mac/foundation_util.h"
+#include "components/strings/grit/components_strings.h"
+#import "ios/chrome/browser/payments/cells/payments_text_item.h"
+#import "ios/chrome/browser/payments/payment_request_selector_view_controller_actions.h"
+#import "ios/chrome/browser/payments/payment_request_selector_view_controller_data_source.h"
+#import "ios/chrome/browser/ui/autofill/cells/status_item.h"
+#import "ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome.h"
+#import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
+#import "ios/chrome/browser/ui/collection_view/cells/collection_view_text_item.h"
+#import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
+#import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
+#import "ios/chrome/browser/ui/icons/chrome_icon.h"
+#include "ios/chrome/browser/ui/uikit_ui_util.h"
+#include "ios/chrome/grit/ios_strings.h"
+#include "ios/chrome/grit/ios_theme_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+
+NSString* const kPaymentRequestSelectorCollectionViewAccessibilityID =
+    @"kPaymentRequestSelectorCollectionViewAccessibilityID";
+
+const CGFloat kSeparatorEdgeInset = 14;
+
+typedef NS_ENUM(NSInteger, SectionIdentifier) {
+  SectionIdentifierItems = kSectionIdentifierEnumZero,
+};
+
+typedef NS_ENUM(NSInteger, ItemType) {
+  ItemTypeHeader = kItemTypeHeaderItem,  // This is a repeated item type.
+  ItemTypeSelectableItem,
+  ItemTypeSpinner,
+  ItemTypeAddItem,
+};
+
+}  // namespace
+
+@interface PaymentRequestSelectorViewController ()<
+    PaymentRequestSelectorViewControllerActions>
+
+@end
+
+@implementation PaymentRequestSelectorViewController
+
+@synthesize delegate = _delegate;
+@synthesize dataSource = _dataSource;
+
+- (instancetype)init {
+  if ((self = [super initWithStyle:CollectionViewControllerStyleAppBar])) {
+    // Set up leading (return) button.
+    UIBarButtonItem* returnButton =
+        [ChromeIcon templateBarButtonItemWithImage:[ChromeIcon backIcon]
+                                            target:nil
+                                            action:@selector(onReturn)];
+    returnButton.accessibilityLabel = l10n_util::GetNSString(IDS_ACCNAME_BACK);
+    self.navigationItem.leftBarButtonItem = returnButton;
+  }
+  return self;
+}
+
+#pragma mark - PaymentRequestSelectorViewControllerActions
+
+- (void)onReturn {
+  [self.delegate paymentRequestSelectorViewControllerDidReturn:self];
+}
+
+#pragma mark - CollectionViewController methods
+
+- (void)loadModel {

[lpromero, 2017/04/11 17:30:19]

I would have seen the model being entirely created by the mediator instead of
mix and match. But as Gauthier raises the issues, this was probably a bad idea I
had :( It makes more sense to have a simpler data source API that only asks for
the relevant bits of info.

Since this controller is pretty specific in its use case (list of strings, add
button), I think it would be a better way to reuse code.
Sorry for throwing you in that direction :(

[Moe, 2017/04/14 06:05:49]

Acknowledged. I think we're now on the same page about this model. 

+  [super loadModel];
+  CollectionViewModel* model = self.collectionViewModel;
+
+  [model addSectionWithIdentifier:SectionIdentifierItems];
+
+  // If the view controller is in the pending state, only display a spinner and
+  // a message indicating the pending state.
+  if (self.dataSource.state == PaymentRequestSelectorStatePending) {
+    StatusItem* statusItem = [[StatusItem alloc] initWithType:ItemTypeSpinner];
+    statusItem.state = StatusItemState::VERIFYING;
+    statusItem.text = l10n_util::GetNSString(IDS_PAYMENTS_CHECKING_OPTION);
+    [model addItem:statusItem toSectionWithIdentifier:SectionIdentifierItems];
+    return;
+  }
+
+  CollectionViewItem* headerItem = [self.dataSource headerItem];
+  if (headerItem) {
+    [model addItem:headerItem toSectionWithIdentifier:SectionIdentifierItems];
+  }
+
+  NSArray<CollectionViewItem*>* selectableItems =
+      [self.dataSource selectableItems];
+  for (NSUInteger index = 0; index < selectableItems.count; ++index) {
+    CollectionViewItem* item = selectableItems[index];
+    item.accessibilityTraits |= UIAccessibilityTraitButton;
+    item.accessoryType = (index == self.dataSource.selectedItemIndex)
+                             ? MDCCollectionViewCellAccessoryCheckmark
+                             : MDCCollectionViewCellAccessoryNone;
+    [model addItem:item toSectionWithIdentifier:SectionIdentifierItems];
+  }
+
+  if ([[self.dataSource addButtonTitle] length]) {
+    PaymentsTextItem* addButton =
+        [[PaymentsTextItem alloc] initWithType:ItemTypeAddItem];
+    addButton.text = [self.dataSource addButtonTitle];
+    addButton.image = NativeImage(IDR_IOS_PAYMENTS_ADD);
+    addButton.accessibilityTraits |= UIAccessibilityTraitButton;
+    [model addItem:addButton toSectionWithIdentifier:SectionIdentifierItems];
+  }
+}
+
+- (void)viewDidLoad {
+  [super viewDidLoad];
+  self.collectionView.accessibilityIdentifier =
+      kPaymentRequestSelectorCollectionViewAccessibilityID;
+
+  // Customize collection view settings.
+  self.styler.cellStyle = MDCCollectionViewCellStyleCard;
+  self.styler.separatorInset =
+      UIEdgeInsetsMake(0, kSeparatorEdgeInset, 0, kSeparatorEdgeInset);
+}
+
+#pragma mark UICollectionViewDelegate
+
+- (void)collectionView:(UICollectionView*)collectionView
+    didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
+  [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
+
+  CollectionViewModel* model = self.collectionViewModel;
+
+  CollectionViewItem* item = [model itemAtIndexPath:indexPath];
+  switch (item.type) {
+    case ItemTypeSelectableItem: {
+      // Update the currently selected cell, if any.
+      if (self.dataSource.selectedItemIndex != NSUIntegerMax) {
+        CollectionViewItem* selectedItem = [self.dataSource

[lpromero, 2017/04/11 17:30:19]

Are all your items PaymentsTextItem? If so, it should be the one having the
accessoryType property in case it is not approved to move in the parent class.

[Moe, 2017/04/14 06:05:49]

Unfortunately not. This also can't remain blocked on the accessory type property
moving to the parent class. Can we use [(id)item setType:...] as a temporary
measure until we resolve that issue?

+            selectableItemAtIndex:self.dataSource.selectedItemIndex];
+        selectedItem.accessoryType = MDCCollectionViewCellAccessoryNone;
+        [self reconfigureCellsForItems:@[ selectedItem ]
+               inSectionWithIdentifier:SectionIdentifierItems];
+      }
+
+      // Update the newly selected cell.
+      item.accessoryType = MDCCollectionViewCellAccessoryCheckmark;
+      [self reconfigureCellsForItems:@[ item ]
+             inSectionWithIdentifier:SectionIdentifierItems];
+
+      // Notify the delegate of the selection.
+      NSUInteger index =
+          [self.collectionViewModel indexInItemTypeForIndexPath:indexPath];
+      DCHECK(index < [[self.dataSource selectableItems] count]);
+      [self.delegate paymentRequestSelectorViewController:self
+                                     didSelectItemAtIndex:index];
+      break;
+    }
+    case ItemTypeAddItem: {
+      [self.delegate paymentRequestSelectorViewControllerDidSelectAddItem:self];
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+#pragma mark MDCCollectionViewStylingDelegate
+
+- (CGFloat)collectionView:(UICollectionView*)collectionView
+    cellHeightAtIndexPath:(NSIndexPath*)indexPath {
+  CollectionViewItem* item =
+      [self.collectionViewModel itemAtIndexPath:indexPath];
+
+  UIEdgeInsets inset = [self collectionView:collectionView
+                                     layout:collectionView.collectionViewLayout
+                     insetForSectionAtIndex:indexPath.section];
+
+  return [MDCCollectionViewCell
+      cr_preferredHeightForWidth:CGRectGetWidth(collectionView.bounds) -
+                                 inset.left - inset.right
+                         forItem:item];
+}
+
+- (BOOL)collectionView:(UICollectionView*)collectionView
+    hidesInkViewAtIndexPath:(NSIndexPath*)indexPath {
+  NSInteger type = [self.collectionViewModel itemTypeForIndexPath:indexPath];
+  if (type == ItemTypeHeader) {
+    return YES;
+  } else {
+    return NO;
+  }
+}
+
+@end