SwiftUI wrapper around Slack's PanModal (https://github.com/slackhq/PanModal)

ContentView.swift

import SwiftUI
import PanModal

struct ExampleView: View {
    
    @State var detail: AnyView? = nil
    @State var items: [String] = ["Detail 1", "Detail 2", "Detail 3"]
    
    var body: some View {
        NavigationView {
            SheetPresenterView(master: master, detail: $detail)
                .navigationBarTitle("Master")
                .navigationBarItems(trailing: Button(action: self.addItem) { Text("Add") })
        }
    }
    
    var master: some View {
        List(items, id: \.self) { item in
            Button(action: { self.detail = AnyView(Text(item)) }) { Text(item) }
        }
    }
    
    func addItem() {
        items.append("Detail \(items.count + 1)")
    }
}

/// SheetPresenterView is a wrapper around SheetMasterController and accepts a master
struct SheetPresenterView<Master: View, Detail: View>: UIViewControllerRepresentable {

    var master: Master
    @Binding var detail: Detail?
    
    func makeUIViewController(context: Context) -> SheetMasterController {
        let controller = SheetMasterController(masterController: UIHostingController(rootView: master))
        controller.didDismiss = { self.detail = nil }
        return controller
    }
    
    func updateUIViewController(_ uiViewController: SheetMasterController, context: Context) {
        uiViewController.masterController = UIHostingController(rootView: master)
        if let view = detail {
            uiViewController.detailController = UIHostingController(rootView: view)
        }
    }
}

/// SheetMasterController contains and manages the master and detail view controllers.
class SheetMasterController: UIViewController {
    
    var masterController: UIViewController {
        willSet { removeMaster() }
        didSet { addMaster() }
    }
    
    var detailController: UIViewController? = nil {
        didSet {
            guard let viewController = detailController else { return }
            guard !isPanModalPresented else { return }
            presentPanModal(SheetDetailController(rootViewController: viewController))
        }
    }
    
    var didDismiss: (() -> Void)? = nil
    
    init(masterController: UIViewController) {
        self.masterController = masterController
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        addMaster()
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        didDismiss?()
    }
    
    func addMaster() {
        guard isViewLoaded else { return }
        masterController.view.frame = view.bounds
        masterController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.addSubview(masterController.view)
        
        addChild(masterController)
        masterController.didMove(toParent: self)
    }
    
    func removeMaster() {
        masterController.willMove(toParent: nil)
        masterController.removeFromParent()
        masterController.view.removeFromSuperview()
    }
}

/// SheetDetailController implements the PanModalPresentable protocol and manages the detail presentation.
class SheetDetailController: UIViewController, PanModalPresentable {
    
    let rootViewController: UIViewController
    
    init(rootViewController: UIViewController) {
        self.rootViewController = rootViewController
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    var panScrollable: UIScrollView? {
        return nil
    }
    
    var shortFormHeight: PanModalHeight {
        return .contentHeight(400)
    }
    
    var showDragIndicator: Bool {
        return false
    }
    
    var panModalBackgroundColor: UIColor {
        return UIColor(white: 0, alpha: 0.1)
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        
        rootViewController.view.frame = view.bounds
        rootViewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.addSubview(rootViewController.view)
        addChild(rootViewController)
        rootViewController.didMove(toParent: self)
    }
}

Thanks for your example! But I got some problem when adding a ScrollView to detail view, the gesture doesn't work well. Do you have a way to fix it?