ScreenMonitoringNotifier

Abstract - ScreenMonitoringNotifier.md

ScreenMonitoringNotifier

ScreenMonitoringNotifier uses a timer with a specific timeInterval - default is 1 second - to check whether any screen is potentially being monitored. Potentially being monitored includes active screen recordings and the use of external displays.

Use ScreenMonitoringNotifier.shared to send out notifications or instantiate your own ScreenMonitoringNotifier to use callbacks.

ScreenMonitoringNotifier.swift

@available(iOS 10.0, *)
public class ScreenMonitoringNotifier {

    // MARK: - Static properties

    public static let isRecordingNotification = Notification.Name(String(describing: ScreenMonitoringNotifier.self) + "." + #function)
    public static let isRecordingNotificationKey = "isRecording"

    public static let shared = ScreenMonitoringNotifier { isRecording in
        NotificationCenter.default.post(name: isRecordingNotification, object: nil, userInfo: [isRecordingNotificationKey: isRecording])
    }

    // MARK: - Stored properties

    private let callback: (Bool) -> Void
    private var timer: Timer?
    public private(set) var lastStatus: Bool?

    // MARK: - Init

    public init(timeInterval: TimeInterval = 1, callback: @escaping (Bool) -> Void) {
        self.callback = callback
        restartTimer(withInterval: timeInterval)
        lastStatus = isRecordingOrMirroring()
    }

    // MARK: - Methods

    public func restartTimer(withInterval interval: TimeInterval? = nil) {
        let interval = interval ?? timer?.timeInterval ?? 1
        self.timer?.invalidate()
        self.timer = Timer(timeInterval: interval, repeats: true, block: { [weak self] _ in self?.timerExpired() })
    }

    // MARK: - Helpers

    private func timerExpired() {
        let currentStatus = isRecordingOrMirroring()
        defer { lastStatus = currentStatus }
        if currentStatus != lastStatus { callback(currentStatus) }
    }

    private func isRecordingOrMirroring() -> Bool {
        for screen in UIScreen.screens {
            if #available(iOS 11.0, *) {
                guard !screen.isCaptured else { return true }
            }
            guard screen.mirrored == nil else { return true }
        }
        return false
    }
}