Build Coupon UI - Setup path

CouponLayout.kt

class CouponLayout : FrameLayout {
    /* ... */
    private fun setupPath() {
        path.apply {
            reset()
            moveTo(/* Start point */)
            topRightCorner    (areaWidth, areaHeight, borderWidth, cornerRadius)
            rightSemiCircle   (areaWidth, areaHeight, borderWidth, semiCircleRadius)
            bottomRightCorner (areaWidth, areaHeight, borderWidth, cornerRadius)
            bottomSemiCircle  (areaWidth, areaHeight, borderWidth, semiCircleRadius)
            bottomLeftCorner  (areaWidth, areaHeight, borderWidth, cornerRadius)
            leftSemiCircle    (areaWidth, areaHeight, borderWidth, semiCircleRadius)
            topLeftCorner     (areaWidth, areaHeight, borderWidth, cornerRadius)
            topSemiCircle     (areaWidth, areaHeight, borderWidth, semiCircleRadius)
            close()
        }
    }
}