SwiftUI Repaint View Components on Device Rotation

Question

How to detect device rotation in SwiftUI and re-draw view components?

I have a @State variable initialized to the value of UIScreen.main.bounds.width when the first

Answer 1

I tried some of the previous answers, but had a few problems. One of the solutions would work 95% of the time but would screw up the layout every now and again. Other solutions didn't seem to be in tune with SwiftUI's way of doing things. So I came up with my own solution. You might notice that it combines features of several previous suggestions.

// Device.swift
import Combine
import UIKit

final public class Device: ObservableObject {

  @Published public var isLandscape: Bool = false

public init() {}

}

//  SceneDelegate.swift
import SwiftUI

class SceneDelegate: UIResponder, UIWindowSceneDelegate {

    var window: UIWindow?
    var device = Device()

   func scene(_ scene: UIScene, 
        willConnectTo session: UISceneSession, 
        options connectionOptions: UIScene.ConnectionOptions) {

        let contentView = ContentView()
             .environmentObject(device)
        if let windowScene = scene as? UIWindowScene {
        // standard template generated code
        // Yada Yada Yada

           let size = windowScene.screen.bounds.size
           device.isLandscape = size.width > size.height
        }
}
// more standard template generated code
// Yada Yada Yada
func windowScene(_ windowScene: UIWindowScene, 
    didUpdate previousCoordinateSpace: UICoordinateSpace, 
    interfaceOrientation previousInterfaceOrientation: UIInterfaceOrientation, 
    traitCollection previousTraitCollection: UITraitCollection) {

    let size = windowScene.screen.bounds.size
    device.isLandscape = size.width > size.height
}
// the rest of the file

// ContentView.swift
import SwiftUI

struct ContentView: View {
    @EnvironmentObject var device : Device
    var body: some View {
            VStack {
                    if self.device.isLandscape {
                    // Do something
                        } else {
                    // Do something else
                        }
                    }
      }
}