Clip View By Rect

ViewEx.kt

fun BottomAppBar.clipTopCorners() {
    elevation = resources.getDimensionPixelSize(R.dimen.dp2).toFloat()
    outlineProvider = object : ViewOutlineProvider() {
        override fun getOutline(view: View, outline: Outline) {
            outline.offset(0, resources.getDimensionPixelSize(R.dimen.dp24))
            outline.setRoundRect(
                0,
                0,
                view.width,
                view.height + resources.getDimensionPixelSize(R.dimen.dp24),
                resources.getDimensionPixelSize(R.dimen.dp24).toFloat()
            )
        }
    }
    setClipToOutline(true)
}