Presenting a UIViewController from an embedded ViewController keeping its bounds - ios

Question

I try to present a ViewController modally from a parent ViewController that's already embedded in a UIView. But whenever I try presenting it, it just pops over the entire window. I want it to be equally sized as its parent. I do not need an animation for the transition. The only thing that worked so far is to again add it's view manually and manipulate the constraints via auto layout. Therefore I would present the controller by hiding its corresponding view. But compared to present that seems more like a workaround than a solution. So far I tried some options on modalPresentationStyle, but none of them seem to work for me. Glad for any help.
Cheers!
class ViewController: UIViewController {
lazy var containerView: UIView = {
let view = UIView()
view.backgroundColor = .red
return view
}()
lazy var viewController: ParentViewController = {
let viewController = ParentViewController()
return viewController
}()
override func viewDidLoad() {
super.viewDidLoad()
containerView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(containerView)
containerView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
containerView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
containerView.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.75).isActive = true
containerView.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.75).isActive = true
viewController.view.translatesAutoresizingMaskIntoConstraints = false
containerView.addSubview(viewController.view)
viewController.view.leadingAnchor.constraint(equalTo: containerView.leadingAnchor).isActive = true
viewController.view.trailingAnchor.constraint(equalTo: containerView.trailingAnchor).isActive = true
viewController.view.topAnchor.constraint(equalTo: containerView.topAnchor).isActive = true
viewController.view.bottomAnchor.constraint(equalTo: containerView.bottomAnchor).isActive = true
viewController.didMove(toParent: self)
}
}
class ParentViewController: UIViewController {
#IBAction func buttonPressed(_ button: UIButton) {
let childController = UIViewController() // This View Controller should fit it´s parents size. Instead it´s just presented normally and fits the window
present(childController, animated: false)
}
}
Edit
Derived from the community answers I implemented following solution:
extension UIViewController {
func open(_ viewControllerToPresent: UIViewController, in view: UIView? = nil, animated: Bool, duration: TimeInterval = 0.25, completion: (() -> Void)? = nil) {
viewControllerToPresent.view.isHidden = true
open(viewControllerToPresent, in: view)
if animated {
viewControllerToPresent.view.alpha = 0.0
viewControllerToPresent.view.isHidden = false
UIView.animate(withDuration: duration) {
viewControllerToPresent.view.alpha = 1.0
} completion: { (_) in
completion?()
}
}
else {
viewControllerToPresent.view.isHidden = false
completion?()
}
}
func open(_ viewControllerToPresent: UIViewController, in view: UIView? = nil) {
let parentView = view ?? self.view!
addChild(viewControllerToPresent)
viewControllerToPresent.view.translatesAutoresizingMaskIntoConstraints = false
parentView.addSubview(viewControllerToPresent.view)
viewControllerToPresent.view.leadingAnchor.constraint(equalTo: parentView.leadingAnchor).isActive = true
viewControllerToPresent.view.trailingAnchor.constraint(equalTo: parentView.trailingAnchor).isActive = true
viewControllerToPresent.view.topAnchor.constraint(equalTo: parentView.topAnchor).isActive = true
viewControllerToPresent.view.bottomAnchor.constraint(equalTo: parentView.bottomAnchor).isActive = true
viewControllerToPresent.didMove(toParent: self)
}
func close(animated: Bool, duration: TimeInterval = 0.25, completion: (() -> Void)? = nil) {
if animated {
UIView.animate(withDuration: duration) {
self.view.alpha = 0.0
} completion: { (_) in
self.close()
completion?()
}
}
else {
close()
completion?()
}
}
func close() {
view.removeFromSuperview()
willMove(toParent: nil)
removeFromParent()
}
}