Detect appbar offset

AppBarOffsetChangeListener.kt

binding.appBar.addOnOffsetChangedListener(AppBarLayout.OnOffsetChangedListener { _, verticalOffset ->
    // By updating the LayoutParams, we trigger the offset change listener, which then results in a somewhat infinite loop.
    // This flag makes sure that we discard the next callback after updating the layout.
    if (verticalOffset == lastOffset) {
        return@OnOffsetChangedListener
    }
    val offsetPercentage = verticalOffset / -maxOffset // 0 is fully expanded, 1 is fully collapsed
    val interpolatedPercentage = interpolator.getInterpolation(offsetPercentage)
    val baseWidth = expandedTextWidth - (expandedTextWidth - collapsedTextWidth) * interpolatedPercentage
    val marginExtra = expandedMargin - (expandedMargin - collapsedMargin) * offsetPercentage
    val fullWidth = baseWidth + marginExtra + extraWidth
    lastOffset = verticalOffset
    binding.clickableLayout.updateLayoutParams<CollapsingToolbarLayout.LayoutParams> {
        width = fullWidth.toInt()
    }
    binding.clickableLayout.updatePadding(bottom = ((expandedBottomPadding - (expandedBottomPadding - collapsedBottomPadding) * offsetPercentage).toInt()))
})
    }