Suggestions UI - stack item

ios/chrome/browser/ui/suggestions/suggestions_collection_updater.mm

 // Copyright 2016 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/ui/suggestions/suggestions_collection_updater.h"
 
+#include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
 #import "ios/chrome/browser/ui/suggestions/suggestions_article_item.h"
 #import "ios/chrome/browser/ui/suggestions/suggestions_expandable_item.h"
 #import "ios/chrome/browser/ui/suggestions/suggestions_item.h"
+#import "ios/chrome/browser/ui/suggestions/suggestions_stack_item.h"
 #import "ios/chrome/browser/ui/suggestions/suggestions_view_controller.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-namespace {
-typedef NS_ENUM(NSInteger, ItemType) {
-  ItemTypeText = kItemTypeEnumZero,
-  ItemTypeArticle,
-  ItemTypeExpand,
-};
+@implementation SuggestionsCollectionUpdater
 
-}  // namespace
+@synthesize collectionViewController = _collectionViewController;
 
-@implementation SuggestionsCollectionUpdater {
-  SuggestionsViewController* _collectionViewController;
-}
+#pragma mark - Properties
 
-- (instancetype)initWithCollectionViewController:
+- (void)setCollectionViewController:
     (SuggestionsViewController*)collectionViewController {
-  self = [super init];
-  if (self) {
-    _collectionViewController = collectionViewController;
-    [collectionViewController loadModel];
-    CollectionViewModel* model = collectionViewController.collectionViewModel;
-    NSInteger sectionIdentifier = kSectionIdentifierEnumZero;
-    for (NSInteger i = 0; i < 3; i++) {
-      [model addSectionWithIdentifier:sectionIdentifier];
-      [model addItem:[[SuggestionsItem alloc] initWithType:ItemTypeText
-                                                     title:@"The title"
-                                                  subtitle:@"The subtitle"]
-          toSectionWithIdentifier:sectionIdentifier];
-      [model addItem:
-                 [[SuggestionsArticleItem alloc]
-                     initWithType:ItemTypeArticle
-                            title:@"Title of an Article"
-                         subtitle:@"This is the subtitle of an article, can "
-                                  @"spawn on multiple lines"
-                            image:[UIImage imageNamed:@"distillation_success"]]
-          toSectionWithIdentifier:sectionIdentifier];
-      SuggestionsExpandableItem* expandableItem =
-          [[SuggestionsExpandableItem alloc]
-              initWithType:ItemTypeExpand
-                     title:@"Title of an Expandable Article"
-                  subtitle:@"This Article can be expanded to display "
-                           @"additional information or interaction "
-                           @"options"
-                     image:[UIImage imageNamed:@"distillation_fail"]
-                detailText:@"Details shown only when the article is "
-                           @"expanded. It can be displayed on "
-                           @"multiple lines."];
-      expandableItem.delegate = collectionViewController;
-      [model addItem:expandableItem toSectionWithIdentifier:sectionIdentifier];
-      sectionIdentifier++;
-    }
+  _collectionViewController = collectionViewController;
+  [collectionViewController loadModel];
+  CollectionViewModel* model = collectionViewController.collectionViewModel;
+  NSInteger sectionIdentifier = kSectionIdentifierEnumZero;
+  [model addSectionWithIdentifier:sectionIdentifier];
+  [model addItem:[[SuggestionsStackItem alloc] initWithType:ItemTypeStack
+                                                      title:@"The title"
+                                                   subtitle:@"The subtitle"]
+      toSectionWithIdentifier:sectionIdentifier++];
+
+  for (NSInteger i = 0; i < 3; i++) {
+    [model addSectionWithIdentifier:sectionIdentifier];
+    [model addItem:[[SuggestionsItem alloc] initWithType:ItemTypeText
+                                                   title:@"The title"
+                                                subtitle:@"The subtitle"]
+        toSectionWithIdentifier:sectionIdentifier];
+    [model addItem:[[SuggestionsArticleItem alloc]
+                       initWithType:ItemTypeArticle
+                              title:@"Title of an Article"
+                           subtitle:@"This is the subtitle of an article, can "
+                                    @"spawn on multiple lines"
+                              image:[UIImage
+                                        imageNamed:@"distillation_success"]]
+        toSectionWithIdentifier:sectionIdentifier];
+    SuggestionsExpandableItem* expandableItem =
+        [[SuggestionsExpandableItem alloc]
+            initWithType:ItemTypeExpand
+                   title:@"Title of an Expandable Article"
+                subtitle:@"This Article can be expanded to display "
+                         @"additional information or interaction "
+                         @"options"
+                   image:[UIImage imageNamed:@"distillation_fail"]
+              detailText:@"Details shown only when the article is "
+                         @"expanded. It can be displayed on "
+                         @"multiple lines."];
+    expandableItem.delegate = _collectionViewController;
+    [model addItem:expandableItem toSectionWithIdentifier:sectionIdentifier];
+    sectionIdentifier++;
   }
-  return self;
 }
 
 #pragma mark - Public methods
 
 - (void)addTextItem:(NSString*)title
            subtitle:(NSString*)subtitle
           toSection:(NSInteger)inputSection {
+  DCHECK(_collectionViewController);
   SuggestionsItem* item = [[SuggestionsItem alloc] initWithType:ItemTypeText
                                                           title:title
                                                        subtitle:subtitle];
   NSInteger sectionIdentifier = kSectionIdentifierEnumZero + inputSection;
   NSInteger sectionIndex = inputSection;
   CollectionViewModel* model = _collectionViewController.collectionViewModel;
   if ([model numberOfSections] <= inputSection) {
     sectionIndex = [model numberOfSections];
     sectionIdentifier = kSectionIdentifierEnumZero + sectionIndex;
     [_collectionViewController.collectionView performBatchUpdates:^{
@@ skipping 10 matching lines @@
                                  toSectionWithIdentifier:sectionIdentifier];
   [_collectionViewController.collectionView performBatchUpdates:^{
     [_collectionViewController.collectionView
         insertItemsAtIndexPaths:@[ [NSIndexPath
                                     indexPathForRow:numberOfItemsInSection
                                           inSection:sectionIndex] ]];
   }
                                                      completion:nil];
 }
 
+- (BOOL)shouldUseCustomStyleForSection:(NSInteger)section {
+  return section == 0;
+}
+
 @end