UITableViewController.UIView.trailingAnchor has different position than UIViewController.UIView.trailingAnchor - ios

Question

I have a method to add two circles to the background view. When added to the view of a UIViewController, they get added correctly. However, when added to the view of a UITableViewController, they get added to the other side.
The method to create the circles is:
extension UIViewController {
func makeCircle(radius: CGFloat) -> UIView {
let circle = UIView()
circle.backgroundColor = .yellow
circle.translatesAutoresizingMaskIntoConstraints = false
circle.layer.cornerRadius = radius
NSLayoutConstraint.activate([
circle.widthAnchor.constraint(equalToConstant: radius * 2),
circle.heightAnchor.constraint(equalToConstant: radius * 2)])
return circle
}
}
The method to add the circles within the UIViewController extension is:
func addCircles() {
// Center right circle
let circle1Radius = CGFloat(152)
let circle1 = makeCircle(radius: circle1Radius)
view.addSubview(circle1)
NSLayoutConstraint.activate([
circle1.centerYAnchor.constraint(equalTo: view.centerYAnchor),
circle1.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: circle1Radius)])
// Bottom left circle
let circle2Radius = CGFloat(77)
let circle2 = makeCircle(radius: circle2Radius)
view.addSubview(circle2)
NSLayoutConstraint.activate([
circle2.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 70),
circle2.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: -50)])
}
For both classes, the circles get added inside the viewDidLoad method:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
addCircles()
}
}
The ViewController: UIViewController, the view looks correct:
However, for the TableViewController: UITableViewController (exact same viewDidLoad as for controller above), the output looks opposite:
Can someone give me a tip on what I am doing wrong?

Answer 1

Thanks to #matt's comment:
I assume it's because a table view is a scroll view. Remember, constraints from a scroll view's subview to a scroll view have a completely different meaning from constraints from a normal view's subview to its superview. So adding subviews directly to a table view using constraints is going to work oddly.
What solved my issue was to no longer use a UITableViewController, but a "basic" UIViewController that has a UITableView and implements the UITableViewDataSource and the UITableViewDelegate:
class TableViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
addCircles()
}
}