Cannot Center Popover Swift - ios

Question

I am trying to make a popover that will allow users to swipe between images (is there a better approach to this than using a popover?).
Right now to make the popover, I have spend hours googling on simply how to make a rectangle center in the screen. From the internet my code is:
// get a reference to the view controller for the popover
let popController = UIStoryboard(name: "Event", bundle: nil).instantiateViewController(withIdentifier: "carouselPopover")
// set the presentation style
popController.modalPresentationStyle = UIModalPresentationStyle.popover
let width = view.frame.width
popController.preferredContentSize = CGSize(width: width, height: 300)
// set up the popover presentation controller
popController.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection.up
popController.popoverPresentationController?.delegate = self
popController.popoverPresentationController?.sourceView = self.view
popController.popoverPresentationController?.sourceRect = CGRect(x: view.bounds.midX, y: view.bounds.midY, width: 0, height: 0)
popController.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection(rawValue: 0)
// present the popover
self.present(popController, animated: true, completion: nil)
However, for the life of me I cannot understand why the popover is not centered
It only loses its center when I set the popController's preferred content size. Any thoughts?
TL:DR
I want to 1) center the popover on the screen, 2) Make the popover 1:1 ratio, and 3) make the width of the popover proportional to the width of the parent screen. How can I do that without 1000's lines of code.

Answer 1

You can create a custom popover class. Then you establish delegate patterns to determine if user swipes.
protocol PopoverDelegate: class {
func imageviewDidSwipe(_ popover: Popover)
}
class Popover: UIView {
weak var delegate: PopoverDelegate?
init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = UIColor.white
}
func setupImage(_ image: UIImage) {
let imageView = UIView(frame: CGRect.zero)
imageView.image = image
self.addSubview(imageView)
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
imageView.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
imageView.heightAnchor.constraint(equalToConstant: 50).isActive = true // However big you want
imageView.widthAnchor.constraint(equalToConstant: 50).isActive = true // However big you want
}
func showPopover(over view: UIView) {
view.addSubview(self)
translatesAutoResizingMaskIntoConstraints = false
centerXAnchor.contraint(equalTo: view.centerXAnchor).isActive = true
centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
heightAnchor.constraint(equalToConstant: frame.height).isActive = true
widthAnchor.constraint(equalToConstant: frame.width).isActive = true
}
}
To use...
class vC: UIViewController {
func ImageOnClick() {
// change view to where you want popover to show on top of
let popover = Popover(frame: view.frame)
popover.setupImage(image.png)
popover.delegate = self
showPopover(over: view)
}
}
extension vC: PopoverDelegate {
func imageviewDidSwipe(_ popover: Popover) {
// image swiped
}
}