Gesture.swift

class ImperativeShortViewController: UIViewController {
    private var timerCreator: TimerCreator
    
    private var panPresent = false
    private var rotatePresent = false
    private var gestureTimer: TimerType?
    private var secondsLeft = 3
    private var tickCount = 0
    
    init(timerCreator: TimerCreator) {
        self.timerCreator = timerCreator
    }
    
    func handlePan(panGesture: UIPanGestureRecognizerType) {
        if panGesture.state == .Began && self.panPresent == false {
            self.panPresent = true
            self.checkIfBothGesturesPresent()
        } else if panGesture.state == .Ended {
            self.panPresent = false
            self.stopTimerIfNeeded()
        }
    }
    
    func handleRotate(rotateGesture: UIRotationGestureRecognizerType) {
        if rotateGesture.state == .Began && self.rotatePresent == false {
            self.rotatePresent = true
            self.checkIfBothGesturesPresent()
        } else if rotateGesture.state == .Ended {
            self.rotatePresent = false
            self.stopTimerIfNeeded()
        }
    }
    
    private func checkIfBothGesturesPresent() {
        if self.rotatePresent == true && self.panPresent == true && self.gestureTimer == nil {
            self.secondsLeft = 3
            self.gestureTimer = timerCreator(interval: 1, repeats: true, onTick: { [weak self] sender in
                self?.tick(sender)
                })
            delegate?.didStart()
        }
    }
    
    private func stopTimerIfNeeded() {
        if let gestureTimer = gestureTimer {
            gestureTimer.invalidate()
            self.gestureTimer = nil
            self.tickCount = 0
            delegate?.didComplete()
        }
    }
    
    private func tick(timer: TimerType) {
        if self.secondsLeft <= 0 {
            self.stopTimerIfNeeded()
            return
        }
        self.secondsLeft -= 1
        delegate?.didTick(secondsLeft)
        tickCount += 1
    }
}