SwiftUIScrollToNewItemWithTransition.swift

import SwiftUI

struct Item: Identifiable {
    let id = UUID()
    let name: String
}

struct ContentView: View {
    
    @State private var items = [Item(name: "Item 1"), Item(name: "Item 2"), Item(name: "Item 2")]
    @State private var itemToSetVisible: UUID? = nil
    
    var body: some View {
        HStack(spacing: 0) {
            ScrollViewReader { scrollProxy in
                ScrollView {
                    VStack(spacing: 0) {
                        ForEach(items) { item in
                            Text(item.name)
                                .frame(maxWidth: .infinity)
                                .frame(height: 100)
                                .background(Color.gray)
                                .id(item.id)
                                .transition(.slide)
                        }
                    }
                }
                .onChange(of: self.itemToSetVisible) { item in
                    guard item != nil else { return }
                    
                    withAnimation {
                        scrollProxy.scrollTo(item)
                    }
                }
            }
            
            Divider()
            
            Button("Add Item") {
                let newItem =  Item(name: "Item \(self.items.count + 1)")
                
                withAnimation {
                    self.items.append(newItem)
                }
                
                self.itemToSetVisible = newItem.id
            }
            .padding()
        }
    }
}