README2.md

Sheet Functionality pre-iOS 15

If you want 1/2 sheet functionality pre-iOS 15 do this.

Create a new View and Xib

Add a background view:

• background color: System Gray 5
• pin to x4 edges of super view
• rename backgroundView

Add a UITableViewController and embed it in a stackview pinned to the x4 superview edges (not safeArea), but give the topAnchor and value of 300pt. Put this inside backgroundView.

For our header, we are going to add another view to our stack view, and then lay out a label and a button within there.

Add a new view to the stack view (call it headerView).

Give it a height of 44pt same height as navigation bar.

And then add a UILabel and UIButton pinned to the edges and centered with a spacing of 16 pts.

Add a dividerView underneath 1pt hight. Pinned to the left, right, and bottom edges of the headerView. Make systemGray4 color.

Now we just need to hook it up! Create and drag out the following outlets to our view controller. Don' t forget the action on the cancel button.

SelectorViewController

import UIKit

class SelectorViewController: UIViewController {

    let games = [
        "Pacman",
        "Space Invaders",
        "Space Patrol",
    ]

    @IBOutlet var backgroundView: UIView!
    @IBOutlet var containerStackView: UIStackView!
    @IBOutlet var tableView: UITableView!
    @IBOutlet var topAnchorConstraint: NSLayoutConstraint!

    var topAnchorValue: CGFloat

    init(topAnchorValue: CGFloat) {
        self.topAnchorValue = topAnchorValue
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.delegate = self
        tableView.dataSource = self
    }

    @IBAction func cancelTapped(_ sender: Any) {
        dismiss(animated: true)
    }
}

extension SelectorViewController: UITableViewDataSource, UITableViewDelegate {
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell()
        cell.textLabel?.text = games[indexPath.row]
        return cell
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return games.count
    }
}

Now we just need to instantiate and present, passing in the height of that topAnchorConstraint like this:

ViewController

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    @IBAction func presentModal(_ sender: Any) {
        let topAnchorValue = UIScreen.main.bounds.height * 0.5
        let vc = SelectorViewController(topAnchorValue: topAnchorValue)
        vc.modalPresentationStyle = .overCurrentContext
        present(vc, animated: true, completion: nil)
    }
}

If we run this now, we should have a nice half sheet, fully animated, and ready to go.

Gotchas

The only gotcha with rolling your own like this is you will get a different background in dark mode compared to the UISheetPresentationController available in iOS 15.

Not a big deal if you are OK with a different background. Just something to be aware of.