iPhone: Detecting user inactivity/idle time since last screen touch

Question

Has anybody implemented a feature where if the user has not touched the screen for a certain time period, you take a certain action? I\'m trying to figure out the best way t

Answer 1

There's a way to do this app wide without individual controllers having to do anything. Just add a gesture recognizer that doesn't cancel touches. This way, all touches will be tracked for the timer, and other touches and gestures aren't affected at all so no one else has to know about it.

fileprivate var timer ... //timer logic here

@objc public class CatchAllGesture : UIGestureRecognizer {
    override public func touchesBegan(_ touches: Set, with event: UIEvent) {
        super.touchesBegan(touches, with: event)
    }
    override public func touchesEnded(_ touches: Set, with event: UIEvent) {
        //reset your timer here
        state = .failed
        super.touchesEnded(touches, with: event)
    }
    override public func touchesMoved(_ touches: Set, with event: UIEvent) {
        super.touchesMoved(touches, with: event)
    }
}

@objc extension YOURAPPAppDelegate {

    func addGesture () {
        let aGesture = CatchAllGesture(target: nil, action: nil)
        aGesture.cancelsTouchesInView = false
        self.window.addGestureRecognizer(aGesture)
    }
}

In your app delegate's did finish launch method, just call addGesture and you're all set. All touches will go through the CatchAllGesture's methods without it preventing the functionality of others.