How to add a view to a free space?

Question

In my application, the squares have to stand next to each other in a vacant space. The width and height of the square are determined by the stepper.

I tried this code, but I can't figure out how to determine the x and y position for a new square

@objc private func goButtonPressed() {
        let squareView: UIView = {
            let square = UIView()
            square.backgroundColor = .blue
            square.frame.size = CGSize(width: Int(stepperLabel.text!)!, height: Int(stepperLabel.text!)!)
            square.frame.origin = CGPoint(x: 0, y: 0)
            return square
        }()
        gameZone.addSubview(squareView)
    }

Screenshot

Answer 1

Here's a simple example written on the xcode playground. The idea is to increment to have to variables currentRow and currentColumn that are then converted to x and y by multiplying the square width.

import PlaygroundSupport
import UIKit
import Foundation
import PlaygroundSupport

class ExampleViewController: UIViewController {

    let squaresByLine = 4
    var currentRow = 0
    var currentColumn = 0

    lazy var frameSize: CGSize = {
        let width = (view.frame.width / 4)
        return CGSize(width: width, height: width)
    }()

    private lazy var uiButton = {
        let btn = UIButton()
        btn.translatesAutoresizingMaskIntoConstraints = false
        btn.setTitle("Add", for: .normal)
        btn.setTitleColor(.black, for: .normal)
        btn.addAction(UIAction(handler: { [weak self] _ in
            self?.goButtonPressed()
        }), for: .touchUpInside)
        btn.backgroundColor = .green
        return btn
    }()

    private func goButtonPressed() {
        let x = CGFloat(currentColumn) * frameSize.width
        let y = CGFloat(currentRow) * frameSize.width

        debugPrint(x, y)
        let squareView: UIView = {
            let square = UIView()
            square.backgroundColor = .blue
            square.frame.size = frameSize
            square.frame.origin = CGPoint(x: x, y: y)
            return square
        }()
        view.addSubview(squareView)

        if currentColumn + 1 > squaresByLine {
            currentColumn = 0
            currentRow += 1
        } else {
            currentColumn += 1
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        view.addSubview(uiButton)

        NSLayoutConstraint.activate([
            uiButton.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            uiButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
            uiButton.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            uiButton.heightAnchor.constraint(equalToConstant: 80)
        ])
    }

}

let viewController = ExampleViewController()
PlaygroundPage.current.liveView = UINavigationController(rootViewController: viewController)