Add context menu for ContentSuggestions

ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm

Index: ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
diff --git a/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm b/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
index a7590b2fe43a62c57c4d73818ca5035825d390fa..66b50ba211b28c46b34e0d38b5237ae6e759a705 100644
--- a/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
+++ b/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
@@ -61,6 +61,13 @@ const NSTimeInterval kAnimationDuration = 0.35;
 
   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
@@ -185,4 +192,36 @@ const NSTimeInterval kAnimationDuration = 0.35;
   [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