UITableViewRowAction add custom buttons to a row when swiping

example.swift

func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
    let complete = UITableViewRowAction(style: .Normal, title: "Complete") { (action: UITableViewRowAction, indexPath: NSIndexPath) -> Void in
        self.completeRowAtIndexPath(indexPath)
    }
    complete.backgroundColor = UIColor.greenColor()
    
    let delete = UITableViewRowAction(style: .Destructive, title: "Delete") { (action: UITableViewRowAction, indexPath: NSIndexPath) -> Void in
        self.deleteRowAtIndexPath(indexPath)
    }
    delete.backgroundColor = UIColor.redColor()
    return [complete, delete]
}