         c.dataSource = self
         c.delegate = self
         c.backgroundColors = [.clear]
-        c.selectionType = .none
+        c.selectionType = .one
+        
+        c.registerForDraggedTypes([.png, .string, .filePromise])
+        c.setDraggingSourceOperationMask([.copy], forLocal: true)
+        c.setDraggingSourceOperationMask([.copy], forLocal: false)
         
         let l = NSCollectionViewFlowLayout()//NSCollectionViewListLayout()
         //l.globalSections = (32, 0)

                let idxs = (0..<(self.dataSource.count - count)).map {
                    IndexPath(item: $0, section: 0)
                }
                self.collectionView.insertItems(at: Set(idxs))
                self.updateToken = false
            }
        }

            
            self.dataSource.insert(event)
            self.collectionView.performBatchUpdates({
                self.collectionView.animator().insertItems(at: [IndexPath(item: self.dataSource.count - 1, section: 0)])
            }, completionHandler: { b in
                guard shouldScroll else { return }
                self.collectionView.animator().scrollToItems(at: [self.collectionView.indexPathForLastItem()],
