swiftui zoom transition options

gistfile1.txt

import UIKit
import SwiftUI

public typealias ZoomInteractiveDismissHandler = (UIViewController.Transition.ZoomOptions.InteractionContext) -> Bool

public extension View {
    func zoomInteractiveDismissShouldBegin(_ handler: @escaping ZoomInteractiveDismissHandler) -> some View {
        modifier(ZoomTransitionModifier(interactiveDismissShouldBegin: handler))
    }
}

private struct ZoomTransitionModifier: ViewModifier {
    
    var interactiveDismissShouldBegin: ((UIViewController.Transition.ZoomOptions.InteractionContext) -> Bool)?
    
    func body(content: Self.Content) -> some View {
        content
            .background {
                ZoomTransitionAdapter(
                    interactiveDismissShouldBegin: interactiveDismissShouldBegin
                )
            }
    }
}

private struct ZoomTransitionAdapter: UIViewControllerRepresentable {
    var interactiveDismissShouldBegin: ZoomInteractiveDismissHandler?
    
    func makeUIViewController(context: Self.Context) -> ZoomTransitionAdapterController {
        let vc = ZoomTransitionAdapterController()
        vc.view.backgroundColor = .clear
        vc.view.isUserInteractionEnabled = false
        vc.interactiveDismissShouldBegin = interactiveDismissShouldBegin
        return vc
    }
    
    func updateUIViewController(_ uiViewController: ZoomTransitionAdapterController,
                                context: Self.Context) {
        uiViewController.interactiveDismissShouldBegin = interactiveDismissShouldBegin
    }
}


private final class ZoomTransitionAdapterController: UIViewController {
        
    var interactiveDismissShouldBegin: ZoomInteractiveDismissHandler? {
        didSet {
            zoomTransitionOptions?.interactiveDismissShouldBegin = interactiveDismissShouldBegin
        }
    }
    
    private var zoomTransitionOptions: UIViewController.Transition.ZoomOptions? {
        parent?.preferredTransition?.value(forKey: "options") as? UIViewController.Transition.ZoomOptions
    }

    override func viewWillAppear(_  animated: Bool) {
        super.viewWillAppear(animated)
        zoomTransitionOptions?.interactiveDismissShouldBegin = interactiveDismissShouldBegin
    }
}