SwiftUI: Build View from bottom alignment in scrollView

Question

Is there a way to build UI elements in SwiftUI inside scroll view with bottom Alignment?

My use case: I have a screen where the screen has

Spacer (What ever is left after allocating below elements)
LogoView
Spacer() - 30
Some Text - 4/5 lines
Spacer() - 50 (this will be calculated off of GR size Height)
HStack with Two Button - This should be pinned to bottom of view / ScrollView

I would like to know how Can I pin the HStack view to ScrollView Bottom

I've replicated my setup and reproduced my problems in a Swift playground like so

struct ContentView: View {
        var body: some View {
        GeometryReader { gr in
            ScrollView {
                VStack {
                    Spacer()
                    Image(systemName: "applelogo")
                        .resizable()
                        .frame(width: gr.size.width * 0.5, height: gr.size.height * 0.3, alignment: .center)
                    Spacer().padding(.bottom, gr.size.height * 0.01)
                    Text("SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME")
                        .fontWeight(.regular)
                        .foregroundColor(.green)
                        .multilineTextAlignment(.center)
                        .padding(.top, gr.size.height * 0.05)
                        .padding(.horizontal, 40)
                        .layoutPriority(1)
                    Spacer()
                        .frame(minHeight: gr.size.height * 0.12)
                    HStack {
                        Button(action: {

                        }, label: {
                            Text("Button 1")
                        })
                        .foregroundColor(Color.white)
                        .padding(.vertical)
                        .frame(minWidth: 0, maxWidth: .infinity)
                        .background(Color.blue)
                        .cornerRadius(8)

                        Button(action: {

                        }, label: {
                            Text("Button 2")
                        })
                        .foregroundColor(Color.white)
                        .padding(.vertical)
                        .frame(minWidth: 0, maxWidth: .infinity)
                        .background(Color.blue)
                        .cornerRadius(8)
                    }
                    .padding(.horizontal, 20)
                }
                //.frame(maxWidth: .infinity, maxHeight: .infinity)
            }
        }
    }
}

I understand that when scrollView is introduced in SwiftUI view Spacer length is changed to Zero, Would like to know what's the best way to achieve this

@HarshilPatel Please find the updated description above (hope it helps). I want the buttons to pin from bottom of view (aka Scroll View) — Pablo Dev
Does this answer your question stackoverflow.com/a/58708206/12299030? — Asperi
@Asperi, No. I am not looking to customize scrollView behavior, was looking for approach of how to pin views to scrollView bottom (similar to storyboard bottom constraint). — Pablo Dev
Approach is to have a spacer above your button. The height of this spacer needs to be computed based on scroll view height - (content of scroll view). Then this needs to be passed on up the view hierarchy using PreferenceKey and then use it to set the spacer height — user1046037

Pablo Dev Pablo Dev · Accepted Answer · 2021-01-07T15:35:54

struct SampleView: View {
    var body: some View {
        GeometryReader { gr in
            VStack {
                ScrollView {
                    VStack {

                        // Fills whatever space is left
                        Rectangle()
                            .foregroundColor(.clear)

                        Image(systemName: "applelogo")
                            .resizable()
                            .frame(width: gr.size.width * 0.5, height: gr.size.height * 0.3, alignment: .center)
                            .padding(.bottom, gr.size.height * 0.06)


                        Text("SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME TEXT SOME")
                            .fontWeight(.regular)
                            .foregroundColor(.green)
                            .multilineTextAlignment(.center)
                            .padding(.horizontal, 40)
                            .layoutPriority(1)


                        // Fills 12 %
                        Rectangle()
                            .frame(height: gr.size.height * 0.12)
                            .foregroundColor(.clear)

                        HStack {

                            Button(action: {
                            }, label: {
                                Text("Button 1")
                            })
                            .foregroundColor(Color.white)
                            .padding(.vertical)
                            .frame(minWidth: 0, maxWidth: .infinity)
                            .background(Color.blue)
                            .cornerRadius(8)

                            Button(action: {
                            }, label: {
                                Text("Button 2")
                            })
                            .foregroundColor(Color.white)
                            .padding(.vertical)
                            .frame(minWidth: 0, maxWidth: .infinity)
                            .background(Color.blue)
                            .cornerRadius(8)
                        }
                        .padding(.horizontal, 20)
                        .padding(.bottom, 20)

                    }

                    // Makes the content stretch to fill the whole scroll view, but won't be limited (it can grow beyond if needed)
                    .frame(minHeight: gr.size.height)
                }
            }
        }
    }
}

SwiftUI: Build View from bottom alignment in scrollView

1 Answers