iOS perform action after period of inactivity (no user interaction)

Question

How can I add a timer to my iOS app that is based on user interaction (or lack thereof)? In other words, if there is no user interaction for 2 minutes, I want to have the ap

Answer 1

Swift 3.0 Conversion of the subclassed UIApplication in Vanessa's Answer

class TimerUIApplication: UIApplication {
static let ApplicationDidTimoutNotification = "AppTimout"

    // The timeout in seconds for when to fire the idle timer.
    let timeoutInSeconds: TimeInterval = 5 * 60

    var idleTimer: Timer?

    // Resent the timer because there was user interaction.
    func resetIdleTimer() {
        if let idleTimer = idleTimer {
            idleTimer.invalidate()
        }

        idleTimer = Timer.scheduledTimer(timeInterval: timeoutInSeconds, target: self, selector: #selector(TimerUIApplication.idleTimerExceeded), userInfo: nil, repeats: false)
    }

    // If the timer reaches the limit as defined in timeoutInSeconds, post this notification.
    func idleTimerExceeded() {
        NotificationCenter.default.post(name: NSNotification.Name(rawValue: TimerUIApplication.ApplicationDidTimoutNotification), object: nil)
    }


    override func sendEvent(_ event: UIEvent) {

        super.sendEvent(event)

        if idleTimer != nil {
            self.resetIdleTimer()
        }

        if let touches = event.allTouches {
            for touch in touches {
                if touch.phase == UITouchPhase.began {
                    self.resetIdleTimer()
                }
            }
        }

    }
}