UTM/Platform/iOS/UTMExternalSceneDelegate.swift

//
// Copyright © 2022 osy. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import SwiftUI

class UTMExternalSceneDelegate: NSObject, UIWindowSceneDelegate, ObservableObject {
    var window: UIWindow?
    var screen: UIScreen?
    
    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        guard let windowScene = (scene as? UIWindowScene) else { return }
        
        if session.role == .windowExternalDisplay {
            let window = UIWindow(windowScene: windowScene)
            let viewController = UIHostingController(rootView: UTMSingleWindowView())
            window.rootViewController = viewController
            self.window = window
            window.isHidden = false
            setupDisplayLinkIfNecessary()
        }
    }
    
    func windowScene(_ windowScene: UIWindowScene, didUpdate previousCoordinateSpace: UICoordinateSpace, interfaceOrientation previousInterfaceOrientation: UIInterfaceOrientation, traitCollection previousTraitCollection: UITraitCollection) {
        setupDisplayLinkIfNecessary()
    }

    weak var linkedScreen: UIScreen?

    func setupDisplayLinkIfNecessary() {
        let currentScreen = self.screen
        if currentScreen != linkedScreen {
            // Set up display link
            self.linkedScreen = currentScreen
        }
    }
}