GitHub - skyefreeman/OnTap: Lovely, closure-based touch input handling for iOS.

let button = UIButton()
button.addTarget(self, action: #selector(buttonTouchUpInside), for: .touchUpInside)

/* .. somewhere else in your view or view controller */

func buttonTouchUpInside() {
    print("tapped!")
}

let button = UIButton()
    .on(.touchUpInside) { print("tapped!") }

let button = UIButton()
    .on(.touchDown) { print("touch down!!!") }
    .on(.touchDownRepeat) { print("touch down repeat!!!") }
    .on(.touchUpInside) { print("touch up inside!!!") }
    .on(.touchUpOutside) { print("touch up outside!!!") }

let button = UIButton()
    .on(.touchUpInside) { print("touch up inside") }
    .on(.touchDown) { print("touch down") }

let slider = UISlider().on(.valueChanged) { [unowned self] in
    print("slider new value: \(self.slider.value)")
}

let rightBarButtonItem = UIBarButtonItem(title: NSLocalizedString("Right", comment: ""), style: .plain).onTap {
    print("right barButtonItem tapped!")
}

let someView = UIView()
    .on(.tap, touches: 1) { print("tapped") }
    .on(.leftSwipe, touches: 1) { print("left swipe 1 finger") }
    .on(.leftSwipe, touches: 2) { print("left swipe 2 fingers") }
    .on(.rightSwipe, touches: 1) { print("right swipe") }
    .on(.upSwipe, touches: 1) { print("up swipe") }
    .on(.downSwipe, touches: 1) { print("down swipe") }