     
     internal func decrease(_ sender: UIButton) {
         sender.backgroundColor = UIColor(white: 1.0, alpha: 0.0)
-        continuousTimer?.invalidate()
         continuousTimer = nil
         decreaseValue()
     }
     
     internal func increase(_ sender: UIButton) {
         sender.backgroundColor = UIColor(white: 1.0, alpha: 0.0)
-        continuousTimer?.invalidate()
         continuousTimer = nil
         increaseValue()
     }

    
    func stopContinuous(_ sender: UIButton) {
        // When dragged outside, stop the timer.
        continuousTimer?.invalidate()
    }
    
    func increaseValue() {

        addSubview(increaseButton)
        
        // Control events
        decreaseButton.addTarget(self, action: #selector(decrease(_:)), for: [.touchUpInside, .touchCancel])
        increaseButton.addTarget(self, action: #selector(increase(_:)), for: [.touchUpInside, .touchCancel])
        increaseButton.addTarget(self, action: #selector(stopContinuous(_:)), for: .touchUpOutside)
        decreaseButton.addTarget(self, action: #selector(stopContinuous(_:)), for: .touchUpOutside)
        decreaseButton.addTarget(self, action: #selector(selected(_:)), for: .touchDown)
