     
     
     private func updateSlideControlForTrackingTouch() {
-        if trackingTouch != nil{
-            sliderStrategy.updateSlideControlForTouch(self, touch: trackingTouch!)
+        if let trackingTouch = trackingTouch {
+            sliderStrategy.updateSlideControlForTouch(self, touch: trackingTouch)
         }
     }
     


public class TFSlideControl: UIControl {
    
    public var sliderStrategy: TFSlideControlSliderStrategyProtocol!
    public var resetAfterValueChange: Bool = false
    
    @IBInspectable public var backgroundImage: UIImage! {
        get{
            if let imageView = backgroundView as? UIImageView {
                return imageView.image

    }
    
    private func customInit() {
        let _handleView = UIView()
        _handleView.backgroundColor = UIColor.whiteColor()
        addSubview(_handleView)
        handleView = _handleView
    }
    
    override public func layoutSubviews() {
        super.layoutSubviews()
        
        if let overlayView = overlayView {
            overlayView.frame = self.bounds
        }
        if let backgroundView = backgroundView {
            backgroundView.frame = self.bounds
        }
        if let maskLayer = self.layer.mask {
