Realtime update Constraints - swift

Question

How can i update constraint by tap on the image?
Sorry for the illiterate speech, I just started learning English, just like swift)
How can i update constraints by tap on the image, especially height and width. Please, see the code below. I try to set new value of height and width variables when i tap on the image, and i want the image to become bigger in REALTIME. But is don,t work. Please Help. P.S. Please dont ask me why i need it, just training, and i know what i can do it by CGAfflinetransorm...Thanks
import UIKit
class View: UIView {
let image = UIImageView()
var width: CGFloat = 150
var height: CGFloat = 150
init() {
super.init(frame: CGRect())
backgroundColor = .systemGray
image.backgroundColor = .black
image.image = UIImage(systemName: "circle")!
addSubview(image)
image.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([image.centerXAnchor.constraint(equalTo: centerXAnchor),
image.centerYAnchor.constraint(equalTo: centerYAnchor),
image.heightAnchor.constraint(equalToConstant: height),
image.widthAnchor.constraint(equalToConstant: width)])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
import UIKit
class ViewController: UIViewController {
let mainView = View()
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action: #selector(imageTap))
mainView.image.addGestureRecognizer(tap)
mainView.image.isUserInteractionEnabled = true
view = mainView
}
#objc func imageTap() {
mainView.height = 300
mainView.width = 300
mainView.image.updateConstraints()
mainView.image.layoutIfNeeded()
print("work")
}
}

Answer 1

As Matt says in the comments, the key to this is to work with constraints throughout, rather than trying to mix in absolute dimensions on your view.
You can wrap all the functionality up in the view, rather than having the gesture recogniser in the parent, although you will need to constrain the imageView to the dimensions of its parent view (rather than just to its centre) so that updating the image size will also update the parent view's dimensions to accommodate the growth.
You will need to store the width constraint for the image size as a property so you can access it in the imageTap() method. The example below assumes the image will always be a square, but you could store and manipulate height and width in a similar way if you didn't want them equal.
class View: UIView {
let image = UIImageView()
let inset = 0.0
var imageWidthDimension: NSLayoutConstraint!
init() {
super.init(frame:.zero)
image.backgroundColor = .black
image.image = UIImage(systemName: "circle")!
translatesAutoresizingMaskIntoConstraints = false
addSubview(image)
let tap = UITapGestureRecognizer(target: self, action: #selector(imageTap))
image.addGestureRecognizer(tap)
image.isUserInteractionEnabled = true
image.translatesAutoresizingMaskIntoConstraints = false
imageWidthDimension = image.widthAnchor.constraint(equalToConstant: 150.0)
NSLayoutConstraint.activate([
image.leadingAnchor.constraint(equalTo: leadingAnchor, constant: inset),
image.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -inset),
image.topAnchor.constraint(equalTo: topAnchor, constant: inset),
image.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -inset),
imageWidthDimension,
image.heightAnchor.constraint(equalTo: image.widthAnchor),
])
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
#objc func imageTap() {
imageWidthDimension.constant = 250.0
image.updateConstraints()
}
}