ListView.swift

final class ListViewController: UIViewController {
    private func makeCollectionView() -> UICollectionView {
        var configuration = UICollectionLayoutListConfiguration(appearance: .insetGrouped)
        configuration.headerMode = .supplementary
        let layout = UICollectionViewCompositionalLayout.list(using: configuration)
        let view = UICollectionView(frame: .zero, collectionViewLayout: layout)
        view.backgroundColor = .systemBackground
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }
    
    private lazy var collectionView = makeCollectionView()
    
    override func loadView() {
        title = "Palettes"
        view = UIView(frame: .zero)
        view.addSubview(collectionView)
        NSLayoutConstraint.activate([
            collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            collectionView.topAnchor.constraint(equalTo: view.topAnchor),
            collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
        ])
        viewModel.reloadContent(in: dataSource)
    }
}