Native iOS 15 Adjustable Bottom Sheet In SwiftUI (half bottom sheet)

BottomSheetDesign.swift

import SwiftUI

struct BottomSheetDesign: View {
    
    @State var showSheet: Bool? = nil
    
    var body: some View {
        
        Button(action: { showSheet = true }) {
            
            HStack (spacing: 5) {
                
                Image(systemName: "hand.tap.fill")
                    .font(.system(size: 20, weight: .regular, design: .rounded))
                
                Text("me to bring up adjustable sheet")
                    .font(.system(size: 20, weight: .regular, design: .rounded))
            }
            
        }
        .halfSheet(showSheet: $showSheet) {
            
            ZStack {
                
                Color.blue
                
                ScrollView(.vertical, showsIndicators: false) {
                    
                    VStack {
                        
                        RoundedRectangle(cornerRadius: 12, style: .continuous)
                            .frame(width: 50, height: 8)
                            .padding(.top, -20)
                            .foregroundColor(.black.opacity(0.2))
                        
                        Text("Hello half sheet 🥹")
                            .font(.system(size: 25, weight: .regular, design: .rounded))
                            .foregroundColor(.white)
                            .padding(.top, 70)
                            .padding(.bottom, 10)
                        
                        Button(action: { showSheet = false }) {
                            
                            HStack(spacing: 5) {
                                
                                Image(systemName: "hand.tap.fill")
                                    .font(.system(size: 20, weight: .bold, design: .rounded))
                                    .foregroundColor(.white)
                                
                                Text("me to close sheet")
                                    .font(.system(size: 20, weight: .bold, design: .rounded))
                                    .foregroundColor(.white)
                            }
                            
                        }
                    }
                    .padding(.top, 30)
                }
            }
            .edgesIgnoringSafeArea(.bottom)
        } onDismiss: {
            print("sheet dismissed")
        }
    }
}

struct BottomSheetDesign_Previews: PreviewProvider {
    static var previews: some View {
        BottomSheetDesign()
    }
}

SheetUIKit.swift

import SwiftUI

// Custom Half Sheet Modifier....
extension View {
    //binding show bariable...
    func halfSheet<Content: View>(
        showSheet: Binding<Bool?>,
        @ViewBuilder content: @escaping () -> Content,
        onDismiss: @escaping () -> Void
    ) -> some View {
        return self
            .background(
                HalfSheetHelper(sheetView: content(), showSheet: showSheet, onDismiss: onDismiss)
            )
    }
}

// UIKit integration
struct HalfSheetHelper<Content: View>: UIViewControllerRepresentable {
    
    var sheetView: Content
    let controller: UIViewController = UIViewController()
    @Binding var showSheet: Bool?
    var onDismiss: () -> Void
    
    func makeCoordinator() -> Coordinator {
        Coordinator(parent: self)
    }
    
    func makeUIViewController(context: Context) -> UIViewController {
        controller.view.backgroundColor = .clear
        return controller
    }
    
    func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
        if let showSheet: Bool = showSheet {
            if showSheet {
                let sheetController = CustomHostingController(rootView: sheetView)
                sheetController.presentationController?.delegate = context.coordinator
                uiViewController.present(sheetController, animated: true)
            }
        }
    }
    
    //on dismiss...
    final class Coordinator: NSObject, UISheetPresentationControllerDelegate {
        
        var parent: HalfSheetHelper
        
        init(parent: HalfSheetHelper) {
            self.parent = parent
        }
        
        func presentationControllerWillDismiss(_ presentationController: UIPresentationController) {
            parent.showSheet = false
        }
    }
}

// Custom UIHostingController for halfSheet...
final class CustomHostingController<Content: View>: UIHostingController<Content> {
    override func viewDidLoad() {
        view.backgroundColor = .clear
        if let presentationController = presentationController as? UISheetPresentationController {
            presentationController.detents = [
                .medium(),
                .large()
            ]
            
            //MARK: - sheet grabber visbility
            presentationController.prefersGrabberVisible = false // i wanted to design my own grabber hehehe
            
            // this allows you to scroll even during medium detent
            presentationController.prefersScrollingExpandsWhenScrolledToEdge = false
            
            //MARK: - sheet corner radius
            presentationController.preferredCornerRadius = 30
            
            // for more sheet customisation check out this great article https://sarunw.com/posts/bottom-sheet-in-ios-15-with-uisheetpresentationcontroller/#scrolling
        }
    }
}

public struct LazyView<Content: View>: View {
    private let build: () -> Content
    public init(_ build: @autoclosure @escaping () -> Content) {
        self.build = build
    }
    public var body: Content {
        build()
    }
}

Going to try this out! Btw, the onDismiss block gets passed around a lot, but doesn't seem to actually get called in this jist.

Why on tap sheet not being dismissed?

For DISMISS use the suggestion above and add
else {
uiViewController.dismiss(animated: true)
}

And of course in your own 'sheet' (View) you have to set showSheet = false to trigger the update

Worked for me

aww , good

Excellent, but it doesn't work with EnvironmentObjects.

when I dismiss the sheet using @Environment(\.dismiss) var dismiss from the sheet content, it presents the sheet again immediately .

is there a way to fix this?

Nice one @dankamel!

I got the onDismiss to work by doing this:

func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
	if let showSheet: Bool = showSheet {
		if showSheet {
			let sheetController = CustomHostingController(rootView: sheetView)
			sheetController.presentationController?.delegate = context.coordinator
			uiViewController.present(sheetController, animated: true)
		} else {
			uiViewController.dismiss(animated: true)
			onDismiss()
			self.showSheet = nil
		}
	}
}

Thanks to hints from @Frodothedwarf & @bruijnesteijn

Based on issues that I had, simply closing uiViewController, dismissed whole screen because nature of my screen was pretty complex and nested, what worked for me was, dismissing presented controller

    if showSheet {
                uiViewController.present(sheetController, animated: true)
            } else {
                uiViewController.presentedViewController?.dismiss(animated: true)
                onDismiss()
                DispatchQueue.main.async { //added because of issue on changing showSheet on none supported thread
                    self.showSheet = nil
                }
            }

But its not properly working in ipad.It does not completely occupy the whole width.So If you have any solution for this,kindly let me know.