1import UIKit
2
3final class TopLoadingBanner: UIView {
4    private let spinner = UIActivityIndicatorView(style: .medium)
5    private let titleLabel = UILabel()
6
7    override init(frame: CGRect) {
8        super.init(frame: frame)
9
10        backgroundColor = UIColor.systemGray6
11        layer.cornerRadius = 10
12
13        spinner.startAnimating()
14        titleLabel.text = "Loading"
15        titleLabel.font = .systemFont(ofSize: 13, weight: .semibold)
16
17        let stack = UIStackView(arrangedSubviews: [spinner, titleLabel])
18        stack.axis = .horizontal
19        stack.spacing = 8
20        stack.alignment = .center
21        stack.translatesAutoresizingMaskIntoConstraints = false
22
23        addSubview(stack)
24        NSLayoutConstraint.activate([
25            stack.centerXAnchor.constraint(equalTo: centerXAnchor),
26            stack.centerYAnchor.constraint(equalTo: centerYAnchor)
27        ])
28    }
29
30    required init?(coder: NSCoder) {
31        fatalError("init(coder:) has not been implemented")
32    }
33}

1import UIKit
2
3final class TopLoadingCoordinator {
4    private weak var hostView: UIView?
5    private var banner: TopLoadingBanner?
6
7    func show(in viewController: UIViewController) {
8        guard banner == nil else { return }
9        hostView = viewController.view
10
11        let b = TopLoadingBanner()
12        b.translatesAutoresizingMaskIntoConstraints = false
13        b.alpha = 0
14        viewController.view.addSubview(b)
15
16        NSLayoutConstraint.activate([
17            b.topAnchor.constraint(equalTo: viewController.view.safeAreaLayoutGuide.topAnchor, constant: 6),
18            b.centerXAnchor.constraint(equalTo: viewController.view.centerXAnchor),
19            b.widthAnchor.constraint(greaterThanOrEqualToConstant: 140),
20            b.heightAnchor.constraint(equalToConstant: 34)
21        ])
22
23        UIView.animate(withDuration: 0.2) { b.alpha = 1 }
24        banner = b
25    }
26
27    func hide() {
28        guard let b = banner else { return }
29        UIView.animate(withDuration: 0.2, animations: {
30            b.alpha = 0
31        }, completion: { _ in
32            b.removeFromSuperview()
33        })
34        banner = nil
35    }
36}

1func loadUserProfile() {
2    coordinator.show(in: self)
3
4    Task {
5        defer { DispatchQueue.main.async { self.coordinator.hide() } }
6
7        do {
8            let profile = try await api.fetchProfile()
9            await MainActor.run {
10                self.render(profile)
11            }
12        } catch {
13            await MainActor.run {
14                self.showError(error)
15            }
16        }
17    }
18}