Custom animated transition not working when using rootview - ios

Question

I am trying to create a custom transition, similar to the one that is on the App Store. I used these tutorials:
https://eric-dockery283.medium.com/custom-view-transitions-like-the-new-app-store-a2a1181229b6
https://www.raywenderlich.com/2925473-ios-animation-tutorial-custom-view-controller-presentation-transitions
I have also been experimenting with using the load view to have the root view to create the view, similar to what is used in the answer used here: does loadView get called even if we don't override it in viewcontroller like the other ViewController lifecycle methods?
now what I am doing is that I am using a collectionview, which I want to keep, and when an item is pressed it animate transitions to a new view controller with a larger image, simple.
the problem is that when I combine it with using the loadView with view = rootView() it did not work in some scenarios.
For example:
when I use the modalPresentationStyle = .fullScreen, when I press an item in the collection view the screen just goes black, and then when I press the view hierarchy it shows this:
when I remove the modalPresentationStyle = .fullScreen it does animate but it is the popover transition, which I do not want.
What I want is to have a full screen transition that is animated.
here is the view controller:
class ViewController: UIViewController {
let data = createData()
var transition = PopAnimator()
var rootView = MainView()
private let collectionView: UICollectionView = {
let viewLayout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: viewLayout)
collectionView.backgroundColor = .white
return collectionView
}()
private enum LayoutConstant {
static let spacing: CGFloat = 16.0
static let itemHeight: CGFloat = 200.0
}
override func loadView() {
view = rootView
rootView.collectionView.delegate = self
rootView.collectionView.dataSource = self
}
}
class MainView: UIView {
let collectionView: UICollectionView = {
let viewLayout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: viewLayout)
collectionView.backgroundColor = .white
return collectionView
}()
init() {
super.init(frame: .zero)
setupLayouts()
}
private func setupLayouts() {
backgroundColor = .white
addSubview(collectionView)
collectionView.register(CollectionViewCell.self, forCellWithReuseIdentifier: CollectionViewCell.identifier)
collectionView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
collectionView.topAnchor.constraint(equalTo: safeAreaLayoutGuide.topAnchor),
collectionView.bottomAnchor.constraint(equalTo: safeAreaLayoutGuide.bottomAnchor),
collectionView.leftAnchor.constraint(equalTo: safeAreaLayoutGuide.leftAnchor),
collectionView.rightAnchor.constraint(equalTo: safeAreaLayoutGuide.rightAnchor)
])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
extension ViewController: UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return data.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CollectionViewCell.identifier, for: indexPath) as! CollectionViewCell
cell.dogImg.image = UIImage(named: data[indexPath.row].image)
return cell
}
}
extension ViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
let selected = data[indexPath.row]
let vc = OtherViewController()
vc.transitioningDelegate = self
// vc.modalPresentationStyle = .fullScreen
vc.data = selected
self.present(vc, animated: true)
print(selected)
}
}
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let width = itemWidth(for: view.frame.width, spacing: LayoutConstant.spacing)
return CGSize(width: width, height: LayoutConstant.itemHeight)
}
func itemWidth(for width: CGFloat, spacing: CGFloat) -> CGFloat {
let itemsInRow: CGFloat = 2
let totalSpacing: CGFloat = 2 * spacing + (itemsInRow - 1) * spacing
let finalWidth = (width - totalSpacing) / itemsInRow
return floor(finalWidth)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: LayoutConstant.spacing, left: LayoutConstant.spacing, bottom: LayoutConstant.spacing, right: LayoutConstant.spacing)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return LayoutConstant.spacing
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return LayoutConstant.spacing
}
}
extension ViewController: UIViewControllerTransitioningDelegate {
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
guard let selectedIndexPathCell = self.collectionView.indexPathsForSelectedItems?.first,
let selectedItem = self.collectionView.cellForItem(at: selectedIndexPathCell) as? CollectionViewCell
else { return nil }
guard let originFrame = selectedItem.superview?.convert(selectedItem.frame, to: nil) else {
return transition
}
transition.originFrame = originFrame
transition.presenting = true
return transition
}
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
transition.presenting = false
return transition
}
}
this is the other view that is presented to.
class OtherViewController: UIViewController, UIViewControllerTransitioningDelegate {
var data: DogArr?
var rootView = testView1()
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = .systemBackground
}
override func loadView() {
view = rootView
//rootView.inputViewController?.transitioningDelegate = self
rootView.carImg.image = UIImage(named: data?.image ?? "")
rootView.dismissBtn.addTarget(self, action: #selector(dismissingBtn), for: .touchUpInside)
}
#objc func dismissingBtn() {
self.dismiss(animated: true)
}
}
class testView1: UIView {
var carImg: UIImageView = {
let img = UIImageView()
img.contentMode = .scaleAspectFit
img.translatesAutoresizingMaskIntoConstraints = false
return img
}()
var dismissBtn: UIButton = {
let btn = UIButton()
btn.translatesAutoresizingMaskIntoConstraints = false
btn.setTitle("Done", for: .normal)
btn.titleLabel?.font = UIFont.systemFont(ofSize: 25)
btn.titleLabel?.textAlignment = .center
btn.setTitleColor(.label, for: .normal)
btn.contentMode = .scaleAspectFill
return btn
}()
init() {
super.init(frame: .zero)
self.addSubview(carImg)
self.addSubview(dismissBtn)
carImg.translatesAutoresizingMaskIntoConstraints = false
self.backgroundColor = .systemBackground
NSLayoutConstraint.activate([
carImg.topAnchor.constraint(equalTo: self.topAnchor),
carImg.heightAnchor.constraint(equalTo: self.heightAnchor, multiplier: 0.5),
carImg.widthAnchor.constraint(equalTo: carImg.heightAnchor),
dismissBtn.topAnchor.constraint(equalTo: self.carImg.bottomAnchor, constant: 20),
dismissBtn.centerXAnchor.constraint(equalTo: self.dismissBtn.centerXAnchor),
dismissBtn.widthAnchor.constraint(equalToConstant: 150),
dismissBtn.heightAnchor.constraint(equalToConstant: 75)
])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
I noticed that when I remove the root view and just created everything in the view controller, it seems to work, the thing is that this is just a test for now. The root view in a future project may be very large so I think keeping to a rootview may be a good idea. If there are any other methods similar, please share.
If there is anything I can answer please ask,
Thank you