SAP Fiori for iOS SDK Code Snippet: ApplicationUIManager

ApplicationUIManager.swift

import SAPCommon
import SAPFiori
import SAPFioriFlows
import SAPFoundation

class SnapshotViewController: UIViewController {}

class ApplicationUIManager {
    
    /// Save ViewController while splash/onboarding screens are presented
    private var savedApplicationRootViewController: UIViewController?
    private var onboardingSplashViewController: (UIViewController & InfoTextSettable)?
    private var coveringViewController: UIViewController?

    let window: UIWindow
    
    init(window: UIWindow) {
        self.window = window
    }

    func releaseRootFromMemory() {
        savedApplicationRootViewController = nil
    }
}

// MARK: - ApplicationUIManaging
extension ApplicationUIManager: ApplicationUIManaging {
    
    func hideApplicationScreen(completionHandler: @escaping (Error?) -> Void) {
        defer {
            completionHandler(nil)
        }
        
        // Check whether the covering screen is already presented or not
        guard coveringViewController == nil else { return }
        
        saveApplicationScreenIfNecessary()
        
        coveringViewController = SnapshotViewController()
        
        window.rootViewController = coveringViewController
    }
    
    func showSplashScreenForOnboarding(completionHandler: @escaping (Error?) -> Void) {
        defer {
            completionHandler(nil)
        }
        
        // Check if no splash already presented
        guard onboardingSplashViewController == nil else { return }
        
        setupSplashScreen()
    }
    
    func showSplashScreenForUnlock(completionHandler: @escaping (Error?) -> Void) {
        defer {
            completionHandler(nil)
        }
        
        // Check if no splash already presented
        guard onboardingSplashViewController == nil else { return }
        
        saveApplicationScreenIfNecessary()
        
        setupSplashScreen()
    }
    
    func showApplicationScreen(completionHandler: @escaping (Error?) -> Void) {
        defer {
            completionHandler(nil)
        }
        
        // Check if an application screen has already been presented
        guard isSplashPresented else { return }
        
        // Restore the saved application screen or create a new one
        let appViewController: UIViewController
        
        if let savedViewController = savedApplicationRootViewController {
            appViewController = savedViewController
        } else {
            let appDelegate = (UIApplication.shared.delegate as! AppDelegate)
            let splitViewController = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "MainSplitViewController") as! UISplitViewController
            splitViewController.delegate = appDelegate
            splitViewController.modalPresentationStyle = .currentContext
            splitViewController.preferredDisplayMode = .allVisible
            appViewController = splitViewController
        }
        
        window.rootViewController = appViewController
        
        onboardingSplashViewController = nil
        savedApplicationRootViewController = nil
        coveringViewController = nil
    }
}

// MARK: - Private API
private extension ApplicationUIManager {

    var isSplashPresented: Bool {
        return window.rootViewController is FUIInfoViewController || window.rootViewController is SnapshotViewController
    }
    
    func saveApplicationScreenIfNecessary() {
        if savedApplicationRootViewController == nil, !isSplashPresented {
            savedApplicationRootViewController = window.rootViewController
        }
    }
    
    func setupSplashScreen() {
        onboardingSplashViewController = FUIInfoViewController.createSplashScreenInstanceFromStoryboard()
        
        window.rootViewController = onboardingSplashViewController
        
        // Set the splash screen for the specific presenter
        let modalPresenter = OnboardingFlowProvider.modalUIViewControllerPresenter
        modalPresenter.setSplashScreen(onboardingSplashViewController!)
        modalPresenter.animated = true
    }
}