struct TableRowDM {
    let title: String
    let subTitle: String
    let hidden: Bool
}

let cellId: String = "CellView"

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    @IBOutlet weak var tableView: UITableView!

    let rowData: [TableRowDM] = [
        TableRowDM(title: "Row 1", subTitle: "Short title 1th row", hidden: false),
        TableRowDM(title: "Row 2", subTitle: "Short title 2th row", hidden: true),
        TableRowDM(title: "Row 3", subTitle: "Very long text in subtitle at 3th row to test text wrapping and growing subtitle height", hidden: false),
        TableRowDM(title: "Row 4", subTitle: "Long text in subtitle at 4th row", hidden: false),
        TableRowDM(title: "Row 5", subTitle: "Long text in subtitle at 5th row", hidden: true),
        TableRowDM(title: "Row 6", subTitle: "Long text in subtitle at 6th row", hidden: false),
    ]

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.rowHeight = UITableViewAutomaticDimension
        tableView.estimatedRowHeight = 50
        tableView.tableFooterView = UIView(frame: CGRect.zero)
        tableView.register(UINib(nibName: cellId, bundle: nil), forCellReuseIdentifier: cellId)
        tableView.delegate = self
        tableView.dataSource = self
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! CellView
        let row: TableRowDM = self.rowData[indexPath.row]

        cell.title.text = row.title
        cell.subtitle.text = row.subTitle

        if row.hidden {
            // hide subtitle
            cell.subtitleHeight.isActive = true
            cell.titleToSubtitleGap.constant = 0
        } else {
            // show subtitle
            cell.subtitleHeight.isActive = false
            cell.titleToSubtitleGap.constant = 16
        }
        cell.setNeedsLayout()
        cell.layoutIfNeeded()
        return cell
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return rowData.count
    }
}

-----------------
      |
- titleLabel ----
      |
      | <- titleToSubtitleGap
      |
- subtitleLabel -
      |
-----------------