Center a view inside viewcontroller in iOS Playground app

Question

I'm currently building a swift playground book. Is it possible to center a view inside a view controller while running on an iPad ?

Here's my loadView function of my view controller:

override public func loadView() {
    let view = UIView()
    view.backgroundColor = .white
    view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
    self.view = view

    let frame = CGRect(x: 0, y: 0, width: 375, height: 375)
    let newView = UIView(frame: frame)
    view.addSubview(newView)
}

How can I center the newViewin the view of the view controller?

Thanks !

Answer 1

You can try to do it using Autolayout:

let frame = CGRect(x: 0, y: 0, width: 375, height: 375)
let newView = UIView(frame: frame)
view.addSubview(newView)
newView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    newView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
    newView.leftAnchor.constraint(equalTo: view.leftAnchor),
    newView.rightAnchor.constraint(equalTo: view.rightAnchor),
    newView.widthAnchor.constraint(equalTo: newView.heightAnchor),
])
newView.backgroundColor = UIColor.red

UPDATE

Playground code:

import UIKit
import PlaygroundSupport

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .red
        view.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
        self.view = view

        let frame = CGRect(x: 0, y: 0, width: 375, height: 375)
        let newView = UIView(frame: frame)
        newView.backgroundColor = .blue
        view.addSubview(newView)

        newView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            newView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            newView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            // need to define its size too
            newView.heightAnchor.constraint(equalToConstant: 375),
            newView.widthAnchor.constraint(equalTo: view.heightAnchor),
            ])
    }
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()