Modify article item in ContentSuggestions

ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.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/content_suggestions/content_suggestions_view_controller.h"
 
 #include "base/mac/foundation_util.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/collection_view_model.h"
+#import "ios/chrome/browser/ui/content_suggestions/content_suggestion.h"
+#import "ios/chrome/browser/ui/content_suggestions/content_suggestions_article_item.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_commands.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_item_actions.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_stack_item.h"
 #import "ios/chrome/browser/ui/content_suggestions/content_suggestions_stack_item_actions.h"
 #import "ios/chrome/browser/ui/content_suggestions/expandable_item.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
@@ skipping 41 matching lines @@
 }
 
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
   [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
 
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
-  if (item.type == ItemTypeStack) {
-    [self.suggestionCommandHandler openReadingList];
+  switch (item.type) {
+    case ItemTypeStack:
+      [self.suggestionCommandHandler openReadingList];
+      break;
+    case ItemTypeArticle:
+      [self openArticle:item];
+      break;
+    default:
+      break;
   }
 }
 
 #pragma mark - ContentSuggestionsExpandableCellDelegate
 
 - (void)collapseCell:(UICollectionViewCell*)cell {
   [self expand:NO cell:cell];
 }
 
 - (void)expandCell:(UICollectionViewCell*)cell {
@@ skipping 79 matching lines @@
            inSectionWithIdentifier:sectionIdentifier];
 
     [UIView
         animateWithDuration:kAnimationDuration
                  animations:^{
                    [self.collectionView.collectionViewLayout invalidateLayout];
                  }];
   }
 }
 
+- (void)openArticle:(CollectionViewItem*)item {
+  ContentSuggestionsArticleItem* article =
+      base::mac::ObjCCastStrict<ContentSuggestionsArticleItem>(item);
+  [self.suggestionCommandHandler openURL:article.articleURL];
+}
+
 @end