Add context menu for 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"
@@ skipping 43 matching lines @@
 
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {
   [super viewDidLoad];
 
   _collectionUpdater.collectionViewController = self;
 
   self.collectionView.delegate = self;
   self.styler.cellStyle = MDCCollectionViewCellStyleCard;
+
+  UILongPressGestureRecognizer* longPressRecognizer =
+      [[UILongPressGestureRecognizer alloc]
+          initWithTarget:self
+                  action:@selector(handleLongPress:)];
+  longPressRecognizer.numberOfTouchesRequired = 1;
+  [self.collectionView addGestureRecognizer:longPressRecognizer];
 }
 
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
   [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
 
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
@@ skipping 104 matching lines @@
                  }];
   }
 }
 
 - (void)openArticle:(CollectionViewItem*)item {
   ContentSuggestionsArticleItem* article =
       base::mac::ObjCCastStrict<ContentSuggestionsArticleItem>(item);
   [self.suggestionCommandHandler openURL:article.articleURL];
 }
 
+- (void)handleLongPress:(UILongPressGestureRecognizer*)gestureRecognizer {
+  if (self.editor.editing ||
+      gestureRecognizer.state != UIGestureRecognizerStateBegan) {
+    return;
+  }
+
+  CGPoint touchLocation =
+      [gestureRecognizer locationOfTouch:0 inView:self.collectionView];
+  NSIndexPath* touchedItemIndexPath =
+      [self.collectionView indexPathForItemAtPoint:touchLocation];
+  if (!touchedItemIndexPath ||
+      ![self.collectionViewModel hasItemAtIndexPath:touchedItemIndexPath]) {
+    // Make sure there is an item at this position.
+    return;
+  }
+  CollectionViewItem* touchedItem =
+      [self.collectionViewModel itemAtIndexPath:touchedItemIndexPath];
+
+  if (touchedItem == [self.collectionViewModel
+                         headerForSection:touchedItemIndexPath.section] ||

[lpromero, 2017/02/14 16:18:17]

If you are pressing the header, how come the collection view returns an
indexPath and not nil?

[gambard, 2017/02/15 10:37:56]

It is returning nil actually.
Should I let the test to be defensive?

[lpromero, 2017/02/15 10:48:28]

[self.collectionViewModel itemAtIndexPath:touchedItemIndexPath] can never return
a header.

+      touchedItem.type != ContentSuggestionsItemTypeArticle) {
+    // Do not trigger context menu on headers.

[lpromero, 2017/02/14 16:18:17]

This comment does not seem to talk about the second condition: !Article.

[gambard, 2017/02/15 10:37:56]

Done.

+    return;
+  }
+
+  ContentSuggestionsArticleItem* articleItem =
+      base::mac::ObjCCastStrict<ContentSuggestionsArticleItem>(touchedItem);
+
+  [self.suggestionCommandHandler displayContextMenuForArticle:articleItem
+                                                      atPoint:touchLocation];
+}
+
 @end