ViewPager and TabLayout Dynamic Tab Opacity Interpolation [Kotlin]

ViewPagerTabLayoutInterpolation.kt

view_pager.addOnPageChangeListener(object : ViewPager.SimpleOnPageChangeListener() {
    override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {
        // Interpolate all tab opacity values
        for (index in 0 until tab_layout.tabCount) {
            tab_layout.getTabAt(index)?.updateOpacity(position, positionOffset)
        }
    }

    fun TabLayout.Tab.updateOpacity(position: Int, offset: Float) {
        val diffTab = 1 - abs(position - this.position + offset)

        // Update opacity of containing elements
        customView?.alpha = 0.5f + if (diffTab in 0.0..1.0) (diffTab * 0.5).toFloat() else 0f
        icon?.alpha = 127 + if (diffTab in 0.0..1.0) (diffTab * 128).toInt() else 0
    }
})