How to change background color for tab in tvOS 13? - uitabbarcontroller

Question

TvOS 13. I have a UITabBarController with tabs. And can customize almost everything except this obvious thing: focused tab's background. It's always white.
Guide tells
Specify tints for selected and unselected items
I tried:
view.backgroundColor = .purple
tabBar.tintColor = .yellow
tabBar.barTintColor = .red
tabBar.unselectedItemTintColor = .brown
tabBar.backgroundColor = .green
tabBar.backgroundImage = UIColor.blue.toImage()
tabBar.shadowImage = UIColor.orange.toImage()
tabBar.selectionIndicatorImage = UIColor.burgundy.toImage()
Nothing helped.

Answer 1

After playing a bit with various properties of UITabBar and UITabBarController, I finally figured it out.
The property to change focused items background color is selectionIndicatorTintColor of UITabBarAppearance (documentation).
Since it is available on tvOS >= 13.0, you will have to wrap the assignment like this:
if #available(tvOS 13.0, *) {
tabBar.standardAppearance.selectionIndicatorTintColor = .white
}

Answer 2

For #davidv and other folks, here is my solution:
extension UIView {
func subviews<T:UIView>(ofType type: T.Type) -> [T] {
var result = self.subviews.compactMap { $0 as? T }
for sub in self.subviews {
result.append(contentsOf: sub.subviews(ofType: type))
}
return result
}
}
extension UIViewController {
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
// перекраска кнопки
let allSubviews = tabBar.subviews(ofType: UIView.self)
let whiteSubviews = allSubviews.filter { $0.backgroundColor == .white }
for s in whiteSubviews {
s.backgroundColor = .gold
}
}
}
UPDATE:
For coloring text:
item.setTitleTextAttributes([NSAttributedString.Key.font: font, NSAttributedString.Key.foregroundColor: colorSelected], for: [.focused])
item.setTitleTextAttributes([NSAttributedString.Key.font: font, NSAttributedString.Key.foregroundColor: colorSelected], for: [.highlighted])
item.setTitleTextAttributes([NSAttributedString.Key.font: font, NSAttributedString.Key.foregroundColor: colorUnselected], for: [.normal])
For coloring background:
tabBar.standardAppearance.selectionIndicatorTintColor = .gold

Answer 3

I accomplish this through a UITabBar extension. The view that is displayed on focus contains a UIMotionEffect so we check against that to find it.
#available(tvOS 13.0, *)
extension UITabBar {
var focusBackgroundView: UIView? {
let allSubviews: [UIView] = subviews.flatMap { [$0] + $0.subviews as [UIView] }
return allSubviews.first{ !$0.motionEffects.isEmpty }
}
}
Usage:
myTabBar.focusBackgroundView.backgroundColor = .red