A SwiftUI view that sets UIWindowScene.ResizingRestrictions on its associated UIWindowScene

ResizingRestrictionsView.swift

/// UPDATE: You may want to use this view modifier instead:
/// https://gist.github.com/drewolbrich/90f11b7170267674cbdcb4a0d71ce873

import SwiftUI

/// A view that, when included as a leaf node in a view hierarchy, sets
/// `UIWindowScene.ResizingRestrictions` for the view's `UIWindowScene`.
///
/// Example:
///
///     WindowGroup {
///         ZStack {
///             // Don't show the window resize handle for this window.
///             ResizingRestrictionsView(resizingRestrictions: .none)
///
///             MyView()
///         }
///     }
///
/// This matches the behavior of Apple's visionOS system apps that 
/// aren't resizable, like Settings.
///
/// The alternative, using `defaultSize`, `windowResizability(.contentSize)`, 
/// and `frame`, will result in a window that, while non-resizable, will still 
/// stretch temporarily when the user attempts to resize it.
///
/// This code targets visionOS 1.0 beta 6 and may or may not be required 
/// in future releases of visionOS.
struct ResizingRestrictionsView: UIViewControllerRepresentable {
    
    private let resizingRestrictions: UIWindowScene.ResizingRestrictions

    init(resizingRestrictions: UIWindowScene.ResizingRestrictions) {
        self.resizingRestrictions = resizingRestrictions
    }
    
    class ResizingRestrictionsViewController: UIViewController {
        
        private let resizingRestrictions: UIWindowScene.ResizingRestrictions

        init(resizingRestrictions: UIWindowScene.ResizingRestrictions) {
            self.resizingRestrictions = resizingRestrictions
            super.init(nibName: nil, bundle: nil)
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
        
        private class ResizingRestrictionsView: UIView {
            let resizingRestrictions: UIWindowScene.ResizingRestrictions
            
            init(resizingRestrictions: UIWindowScene.ResizingRestrictions) {
                self.resizingRestrictions = resizingRestrictions
                super.init(frame: .zero)
            }
            
            required init?(coder: NSCoder) {
                fatalError("init(coder:) has not been implemented")
            }
            
            override func didMoveToWindow() {
                window?.windowScene?.requestGeometryUpdate(.Vision(resizingRestrictions: resizingRestrictions))
            }
        }
        
        override func loadView() {
            view = ResizingRestrictionsView(resizingRestrictions: resizingRestrictions)
        }
        
    }
    
    func makeUIViewController(context: Context) -> ResizingRestrictionsViewController {
        return ResizingRestrictionsViewController(resizingRestrictions: resizingRestrictions)
    }
    
    func updateUIViewController(_ uiViewController: ResizingRestrictionsViewController, context: Context) {
        // Do nothing.
    }
    
}