Control ScrollView with ScrollViewReader

[cunhacf]

How can I control the ScrollView when enableAppleScrollBehavior is enabled? I need to be able to scroll to a specific item but it seems that ScrollViewReader doesn't work.

I've tried putting ScrollViewReader inside the bottomSheet as well, no luck.

This is my code, for reference:

var body: some View {
    ScrollViewReader { proxy in
        PackageDetailsMapView(onMapLoaded: { event, mapView in
            self.mapView = mapView
        })
        .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
        .ignoresSafeArea(.all)
        
        .bottomSheet(
            bottomSheetPosition: $bottomSheetPosition,
            switchablePositions: [
                .absolute(200),
                .dynamicTop
            ],
            headerContent: {
                VStack(alignment: .center) {
                    HStack(alignment: .center, spacing: 40) {
                        Image("logo-correios")
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                            .frame(height: 16.0)
                        
                        Text("Entregue em 10 dias")
                            .font(.system(size: 14))
                    }
                    .frame(maxWidth: .infinity)
                    .padding(.all, 8)
                }
            }
        ) {
            ForEach(0..<10) {i in
                Button(action: {
                    mapView?.camera.fly(
                        to: CameraOptions(center: LocationCoordinate2D(latitude: 40.83647410051574, longitude: 14.30582273457794), zoom: 9),
                        duration: 1.5
                    )
                    
                    bottomSheetPosition = .absolute(200)
                    
                    DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
                        proxy.scrollTo(4, anchor: .top)
                    }
                    
                    currentEventIndex = i
                }) {
                    HStack(alignment: .top) {
                        HStack(alignment: .top) {
                            ZStack {
                                Circle()
                                    .strokeBorder(Color("DeliveredEventColor"), lineWidth: 1.0)
                                    .background(Color("DeliveredEventColor"))
                                    .frame(width: 34.0, height: 34.0)
                                    .cornerRadius(40.0)
                                    .opacity(0.2)
                                
                                Image("icon-event-delivered")
                                    .resizable()
                                    .aspectRatio(contentMode: .fit)
                                    .frame(width: 18.0, height: 18.0)
                                    .foregroundColor(Color("DeliveredEventColor"))
                            }
                            
                            VStack(alignment: .leading) {
                                Text("Entregue ao destinatário \(i)")
                                    .padding(.bottom, 2)
                                    .foregroundColor(Color("DeliveredEventColor"))
                                    .fontWeight(.bold)
                                    .font(.system(size: 20))
                                
                                Text("17/11/2022 às 22:25, CURITIBA / PR")
                                    .font(.system(size: 14))
                                    .fontWeight(.bold)
                                
                                Text("Destino: Unidade de Tratamento")
                                    .font(.system(size: 14))
                            }
                        }
                        .frame(maxWidth: .infinity, alignment: .topLeading)
                        
                        VStack(alignment: .center) {
                            Image("icon-marker")
                                .resizable()
                                .aspectRatio(contentMode: .fit)
                                .frame(width: 18.0, height: 18.0)
                        }
                        .frame(maxHeight: .infinity, alignment: .center)
                        .opacity(currentEventIndex == i ? 1.0 : 0.0)
                    }
                    .frame(maxWidth: .infinity, alignment: .topLeading)
                    .contentShape(Rectangle())
                    .padding(20)
                }
                .id(i)
                .buttonStyle(ListButtonStyle())
            }
        }
        .enableAppleScrollBehavior(true)
    }
    
    .navigationTitle(Text("LB774181834HK"))
    .navigationBarTitleDisplayMode(.inline)
    .toolbarColorScheme(.dark, for: .navigationBar)
    .toolbar(.hidden, for: .tabBar)
}

[lucaszischka]

No unfortunately not. This is due to the fact that the ScrollView used to accomplish the appleScrollBehaviour is not the one of the SwiftUI library, because of its various limitations.

[cunhacf]

Bummer. Any chance something like that could be implemented?

[lucaszischka]

Honestly no. I struggled about a year for getting this feature work at all and still there are issues (see #101). I already once removed it at all, because I saw no possible solution. My current solution, to use a UIScrollView and completely simulate the mechanics (basically creating a ScrollView from scratch, with help of the internet) already took too much time and effort. I won't work on bugs fixes regarding this feature and I also won't extend it (for example by adding a ScrollViewReader. However if anyone wants to do the job themselves and create a pull request, I will of course review it. I think in your case the SwiftUI-Introspect Library might help you. Not sure if it works with UIViews however. Maybe there is an UIKit equivalent out there.