original way to get floating middle button to work for tab bar

floating middle button tab bar

        let buttonImage = UIImage(named: "Btn_Menu_BROWSE_INACTIVE_03")
        let button = UIButton(type: UIButtonType.Custom)
        button.autoresizingMask = [UIViewAutoresizing.FlexibleRightMargin, .FlexibleLeftMargin, .FlexibleBottomMargin, .FlexibleTopMargin]
        button.frame = CGRectMake(0.0, 0.0, buttonImage!.size.width, buttonImage!.size.height);
        let buttonHighlighted = UIImage(named: "Btn_Menu_BROWSE_ACTIVE_03")
        button.setBackgroundImage(buttonImage, forState: UIControlState.Normal)
        button.setBackgroundImage(buttonHighlighted, forState: UIControlState.Highlighted)
        let heightDifference = buttonImage!.size.height - self.tabBar.frame.size.height;
        if (heightDifference < 0) {
            button.center = self.tabBar.center
        } else {
            var center = self.tabBar.center
            center.y = center.y - heightDifference/2.0
            button.center = center
        }
        button.layer.cornerRadius = button.frame.height/2
        button.clipsToBounds = true
        button.addTarget(self, action: "changeTabToBrowse", forControlEvents: UIControlEvents.TouchUpInside)
        view.addSubview(button)
    }

//second more simple way
    private func addCenterButtonWithImage(buttonImage: UIImage, highlightImage:UIImage?)
    {
        let frame = CGRectMake(0.0, 0.0, buttonImage.size.width, buttonImage.size.height)
        button = UIButton(frame: frame)
        button.setBackgroundImage(buttonImage, forState: UIControlState.Normal)
        button.setBackgroundImage(highlightImage, forState: UIControlState.Highlighted)
        
        var heightDifference:CGFloat = buttonImage.size.height - self.tabBar.frame.size.height
        if heightDifference < 0 {
            button.center = self.tabBar.center;
        }
        else
        {
            var center:CGPoint = self.tabBar.center;
            center.y = center.y - heightDifference/2.0;
            button.center = center;
        }
        
        button.addTarget(self, action: "changeTabToMiddleTab:", forControlEvents: UIControlEvents.TouchUpInside)
        
        self.view.addSubview(button)
    }