     var childViewHeight : CGFloat { return screenHeight - barHeight }
     
     // child size
-    var childViewSize: CGRect {
+    var childViewFrame: CGRect {
         
         return CGRect(
             x: 0.0,

    private var barView: BarView!
    private var currentChildView: UIView?
    private var currentChildViewController: UIViewController?

    
    override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() }
    

        
        _barView.delegate = self
        _barView.frame = barViewFrame
        _barView.layer.zPosition = 4.0
        
        self.view.addSubview(_barView)
        
