Using SwiftUI View for UICollectionViewCell - swiftui

Question

I made UICollectionView that accept (Item) -> Content (where Content:View) as init parameter to pass this SwiftUI View to cell content view using UIHostController. But by some reason my screen is empty, however if I pass some View instead of Content directly to UIHosting controller everything works fine.
Code:
Cell
final class SnapCarouselCell<Content:View>: UICollectionViewCell{
var cellContent: Content?
override init(frame: CGRect) {
super.init(frame: frame)
let vc = UIHostingController(rootView: cellContent)
contentView.addSubview(vc.view)
vc.view.translatesAutoresizingMaskIntoConstraints = false
vc.view.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
vc.view.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
vc.view.leftAnchor.constraint(equalTo: contentView.leftAnchor).isActive = true
vc.view.rightAnchor.constraint(equalTo: contentView.rightAnchor).isActive = true
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Controller
class SnapCarouselViewController<Item: Equatable, Content: View>: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource{
lazy var snapCarouselView: UICollectionView = {
let collectionView = setUpCollectionView()
self.view.addSubview(collectionView)
return collectionView
}()
private let flowLayout: UICollectionViewFlowLayout
private let cellHeight: CGFloat
private let cellWidth: CGFloat
private var centerCell: UICollectionViewCell?
private let items: [Item]
private let cellContent: (Item) -> Content
init(
cellHeight: CGFloat,
cellWidth: CGFloat,
items: [Item],
#ViewBuilder cellContent: #escaping (Item) -> Content
){
self.cellHeight = cellHeight
self.cellWidth = cellWidth
self.flowLayout = SnapCarouselViewFlowLayout(cellWidth: cellWidth, cellHeight: cellHeight)
self.items = items
self.cellContent = cellContent
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
snapCarouselView.dataSource = self
snapCarouselView.delegate = self
let indexPath = IndexPath(row: 9999999999, section: 0)
snapCarouselView.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: false)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return Int.max
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "SnapCarouselCell", for: indexPath) as! SnapCarouselCell<Content>
cell.cellContent = cellContent(items[indexPath.row % items.count])
return cell
}
private func setUpCollectionView() -> UICollectionView{
let collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: flowLayout)
collectionView.backgroundColor = .white
collectionView.showsHorizontalScrollIndicator = false
collectionView.frame = CGRect(x: 0, y: 100, width: view.frame.size.width, height: cellHeight)
collectionView.decelerationRate = .fast
collectionView.register(SnapCarouselCell<Content>.self, forCellWithReuseIdentifier: "SnapCarouselCell")
return collectionView
}
}
View
struct SnapCarouselView<Content: View, Item: Equatable>: UIViewControllerRepresentable {
private let cellContent: (Item) -> Content
private let cellHeight: CGFloat
private let cellWidth: CGFloat
private let items: [Item]
init(
cellHeight: CGFloat,
cellWidth: CGFloat,
items: [Item],
#ViewBuilder cellContent: #escaping (Item) -> Content
) {
self.cellHeight = cellHeight
self.cellWidth = cellWidth
self.cellContent = cellContent
self.items = items
}
func makeUIViewController(context: Context) -> SnapCarouselViewController<Item,Content> {
let vc = SnapCarouselViewController(
cellHeight: cellHeight,
cellWidth: cellWidth,
items: items,
cellContent: cellContent)
return vc
}
func updateUIViewController(_ uiViewController: SnapCarouselViewController<Item,Content>, context: Context) {
}
typealias UIViewControllerType = SnapCarouselViewController
}
struct TestUICollectionView_Previews: PreviewProvider {
static var previews: some View {
SnapCarouselView(cellHeight: 200, cellWidth: 200, items: test) { item in
Text(item.name)
}
}
}
struct Test: Equatable{
var id = UUID()
let name : String
}
let test = [
Test(name: "1"),
Test(name: "2"),
Test(name: "3"),
Test(name: "4"),
Test(name: "5"),
Test(name: "6"),
Test(name: "7"),
Test(name: "8"),
Test(name: "9"),
Test(name: "10"),
Test(name: "12"),
Test(name: "12"),
Test(name: "13"),
Test(name: "14"),
Test(name: "15"),
]