How to get the current element in the screen to programmatically scroll from buttons without getting broken by the ScrollViewReader Index

Question

I've been working on a GridView with programmatical scroll support, I've been using ScrollViewReader to programmatically scroll to the top & bottom of the GridView, but I have a trouble, I added two extra buttons to scroll 3 elements per touch, and it's working but there's new trouble with it.

If the user manually scrolls using the ScrollView, the ScrollViewReader shall not work, I mean, the extra buttons to scroll 3 elements per button touch shall not work ('cause the Index is not the current element on the Screen), I need to know the current element in the screen, or a better way to make my idea, here's my code

var body: some View {
    ScrollView([.horizontal, .vertical]) {
        ScrollViewReader { proxy in

            Section(header: HeaderView(screenSize: $screenSize).border(Color("ApplicationTint"), width: 4)) {
                ForEach(Elements.indices) { index in
                    Row(screenSize: $screenSize, elements: Elements[index])
                        .id(index)
                        Divider()
                }
            }
            .onChange(of: viewModel.gridIndex, perform: { value in
                withAnimation(.spring()) {
                    proxy.scrollTo(value, anchor: .leading)
                }
            })
        }
}

Also, the buttons code.

                        Button {
                            viewModel.gridIndex = 0
                        } label: {
                            Image(systemName: "arrow.up.to.line")
                        }

                        Button {
                            viewModel.gridIndex -= 1
                        } label: {
                            Image(systemName: "arrow.up")
                        }

                        Button {
                            viewModel.gridIndex += 1
                        } label: {
                            Image(systemName: "arrow.down")
                        }

                        Button {
                           // viewModel.gridIndex = 0
                            viewModel.gridIndex = 0 + viewModel.totalgridIndex
                        } label: {
                            Image(systemName: "arrow.down.to.line")
                        }