Storyboardにxib利用 ref: http://qiita.com/MTattin/items/61beb3b4afcc779f707f

file0.swift

class VideoNavView: UIView {

    private var v: UIView?

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        v = NSBundle.mainBundle().loadNibNamed(
            "VideoNavView",
            owner: self,
            options: nil
        )[0] as? UIView
        self.addSubview(v!)
    }
}

file1.swift

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        v = NSBundle.mainBundle().loadNibNamed(
            "VideoNavView",
            owner: self,
            options: nil
        )[0] as? UIView
        self.addSubview(v!)

        /* Viewのカスタム */
        spdSdr.setThumbImage(
            UIImage(named: "spdSdrThum"),
            forState: UIControlState.Normal
        )
        spdSdr.setThumbImage(
            UIImage(named: "spdSdrThum"),
            forState: UIControlState.Highlighted
        )
        spdSdr.setThumbImage(
            UIImage(named: "spdSdrThum"),
            forState: UIControlState.Selected
        )
    }

file2.swift

    override func drawRect(rect: CGRect) {
        super.drawRect(rect)

        /* スライダーの右端と左端にViewを配置 */
        var posStBtnR: CGRect = posStBtn.frame
        posStBtnR.x = posSdr.x - (posStBtnR.w * 0.5)
        posStBtnR.y = posSdr.y + (posSdr.h * 0.5)
        posStBtn.frame = posStBtnR

        var posSpBtnR: CGRect = posSpBtn.frame
        posSpBtnR.x = posSdr.x + posSdr.w - (posStBtnR.w * 0.5)
        posSpBtnR.y = posSdr.y + (posSdr.h * 0.5)
        posSpBtn.frame = posSpBtnR
    }