swiftlistbuttonswiftui

Custom Button in SwiftUI List


SwiftUI Custom Button in List

I'm trying to create a custom button in a SwiftUI List. I want it to have a blue background with white text, and importantly, to remain blue and go to 50% opacity when pressed, not the default grey.

I tried using a custom ButtonStyle, but when I do so, the tappable area of the button is reduced to just the label itself. If I tap any other part of the cell, the colour doesn't change. If I remove the ButtonStyle, tapping anywhere on the cell works

How can I fix this so that I get my custom colours, including the colour when tapped, but the whole cell is still tappable?

import SwiftUI

struct BlueButtonStyle: ButtonStyle {

  func makeBody(configuration: Self.Configuration) -> some View {
    configuration.label
        .font(.headline)
        .foregroundColor(configuration.isPressed ? Color.white.opacity(0.5) : Color.white)
        .listRowBackground(configuration.isPressed ? Color.blue.opacity(0.5) : Color.blue)
  }
}

struct ExampleView: View {

    var body: some View {
        NavigationView {
            List {
                Section {
                    Text("Info")
                }

                Section {
                    Button(action: {print("pressed")})
                    {
                        HStack {
                            Spacer()
                            Text("Save")
                            Spacer()
                        }

                    }.buttonStyle(BlueButtonStyle())
                }
            }
            .listStyle(GroupedListStyle())
            .environment(\.horizontalSizeClass, .regular)
            .navigationBarTitle(Text("Title"))
        }
    }
}

struct ExampleView_Previews: PreviewProvider {
    static var previews: some View {
        ExampleView()
    }
}

Solution

  • In standard variant List intercepts and handles content area of tap detection, in your custom style it is defined, by default, by opaque area, which is only text in your case, so corrected style is

    demo

    Update for: Xcode 13.3 / iOS 15.4

    It looks like Apple broken something, because listRowBackground now works only inside List itself, no subview, which is senseless from generic concept of SwiftUI.

    Updated solution with same behavior as on demo

    Original for: Xcode 11.4 / iOS 13.4

    struct BlueButtonStyle: ButtonStyle {
    
      func makeBody(configuration: Self.Configuration) -> some View {
        configuration.label
            .font(.headline)
            .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
            .contentShape(Rectangle())
            .foregroundColor(configuration.isPressed ? Color.white.opacity(0.5) : Color.white)
            .listRowBackground(configuration.isPressed ? Color.blue.opacity(0.5) : Color.blue)
      }
    }
    

    and usage, just

    Button(action: {print("pressed")})
    {
        Text("Save")
    }.buttonStyle(BlueButtonStyle())
    

    and even

    Button("Save") { print("pressed") }
        .buttonStyle(BlueButtonStyle())