SwiftUI background color of List Mac OS

Question

I am using a ListView in Mac OS. I am trying to change that background color of that ListView. However, it is not that easy as expected.

I tried using .background(Color(.red)) attribute on the ListView. That didn't change anything.

I could only find .listRowBackground(Color(.red))which had an influence on the table rows. However, the other background wasn't effected.

I prepared a little demo to demonstrate:

In my view body:

  VStack
    {
        List()
        {
            Text("Test")
                .listRowBackground(Color.green)

            Text("Test")
                .listRowBackground(Color.green)

            Text("Test")
                .listRowBackground(Color.green)

        }.background(Color(.red))

    }.background(Color(.red))

That is the result I get:

The main background does not change. I read about a solution changing the UITableView.appearance but that is not possible for me in SwiftUI for Mac OS.

Thanks in advance

Answer 1

Update 2: I haven't verified this, but user1046037 says there is a new API available for changing scrolling backgrounds: scrollContentBackground.

Update 1: I found a much better way to remove a list's background without affecting the whole app: by using Introspect.

import Introspect
import SwiftUI

extension List {
  /// List on macOS uses an opaque background with no option for
  /// removing/changing it. listRowBackground() doesn't work either.
  /// This workaround works because List is backed by NSTableView.
  func removeBackground() -> some View {
    return introspectTableView { tableView in
      tableView.backgroundColor = .clear
      tableView.enclosingScrollView!.drawsBackground = false
    }
  }
}

Usage:

List {
  ForEach(items) { item in
    ...
  }
}.removeBackground()

Old answer:

@Asperi's answer works, but only until the window is resized. Here's another workaround for overriding List's color:

extension NSTableView {
  open override func viewDidMoveToWindow() {
    super.viewDidMoveToWindow()

    backgroundColor = NSColor.clear
    enclosingScrollView!.drawsBackground = false
  }
}

A potential downside is that this will affect all lists in the app.