CODEWITHSUNDEEP
iosuigesturerecognizeruitapgesturerecognizeruilongpressgesturerecogni
Nick
Nick

Reputation: 3435

How to detect "long tap"

I have a UIView view, and I want to perform some action when user pressed it and then released. I added a UITapGestureRecognizer to the view, and it only fires when tap duration is small. If user touches the view, waits a couple of seconds and then lifts his finger, nothing happens. How can I detect "long tap" events?

UILongPressGestureRecognizer does not work for me because it fires when finger still touches the screen.

Upvotes: 0

Views: 278

Answers (1)

DonMag
DonMag

Reputation: 77423

You can do this by tracking when touchesBegan and touchesEnded:

class LongTapView: UIView {
    
    var touchStart: Date!
    
    var callback: ((Double)->())?
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        touchStart = Date()
    }
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touchPoint = touches.first?.location(in: self),
              self.bounds.contains(touchPoint) else {
            // touch moved outside of self,
            //  so don't consider it "still pressed"
            touchStart = Date.distantFuture
            return
        }
    }
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        guard let touchPoint = touches.first?.location(in: self),
              self.bounds.contains(touchPoint) else {
            // touch was lifted outside of self
            return
        }
        let seconds = -(touchStart.timeIntervalSinceNow)
        if seconds < 0.0 {
            // this will be the case if touchesMoved outside of self
            //  and then was dragged back in
            return
        }
        // tell the controller how long the view was touched
        callback?(seconds)
    }
}

You can use it like this:

class TouchTestViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let v = LongTapView()
        v.frame = CGRect(x: 80, y: 120, width: 150, height: 150)
        v.backgroundColor = .red
        view.addSubview(v)
        
        v.callback = { elapsedTime in
            // do what you want here, for example:
            if elapsedTime > 4.0 {
                print("View was pressed longer than 4 seconds!")
            } else {
                print("View was pressed for only \(elapsedTime) seconds")
            }
        }
        
    }
}

Upvotes: 0

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