Drag_Perform.swift

    func tableView(_ tableView: UITableView, performDropWith coordinator: UITableViewDropCoordinator) {
        if coordinator.items.count == 0 { return }
        let destinationIndexPath = coordinator.destinationIndexPath ?? IndexPath(row: editImages.images.count, section: 0)
        let cellImageWidth = tableView.frame.size.width - tableView.layoutMargins.left - tableView.layoutMargins.right

        for item in coordinator.items {
            let itemProvider = item.dragItem.itemProvider
            if !itemProvider.canLoadObject(ofClass: UIImage.self) { continue }
            itemProvider.loadObject(ofClass: UIImage.self) {(object, error) in
                guard let image = object as? UIImage else { return }
                let cellHeight = image.size.height * (cellImageWidth / image.size.width) + 5
                let placeholder = UITableViewDropPlaceholder(insertionIndexPath: destinationIndexPath, reuseIdentifier: "Cell", rowHeight: cellHeight)
                placeholder.cellUpdateHandler = { cell in
                    if let imageCell = cell as? SURImageTableViewCell {
                        imageCell.iconView.image = image
                    }
                }
                DispatchQueue.main.async {
                    let placeholderContext = coordinator.drop(item.dragItem, to: placeholder)
                    placeholderContext.commitInsertion { insertionIndexPath in
                        self.insertImage(image, indexPath: insertionIndexPath)
                        tableView.insertRows(at: [insertionIndexPath], with: .none)
                        placeholderContext.deletePlaceholder()
                    }
                }
            }
        }
        coordinator.session.progressIndicatorStyle = .none
    }

    func tableView(_ tableView: UITableView, dropSessionDidUpdate session: UIDropSession, withDestinationIndexPath destinationIndexPath: IndexPath?) -> UITableViewDropProposal {
        if session.localDragSession != nil {
            return UITableViewDropProposal(operation: .move, intent: .insertAtDestinationIndexPath)
        } else {
            return UITableViewDropProposal(operation: .copy, intent: .insertAtDestinationIndexPath)
        }
    }