Android CoordinatorLayout Scroll Aware ExtendedFloatingActionButton behavior

ScrollAwareExtendedFabBehavior.kt

package com.example

import android.content.Context
import android.util.AttributeSet
import android.view.View
import androidx.coordinatorlayout.widget.CoordinatorLayout
import androidx.core.view.ViewCompat
import androidx.core.view.isVisible
import com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton

class ScrollAwareExtendedFabBehavior : CoordinatorLayout.Behavior<ExtendedFloatingActionButton> {

    constructor() : super()

    constructor(context: Context, attributeSet: AttributeSet) : super(context, attributeSet)

    override fun onStartNestedScroll(
        coordinatorLayout: CoordinatorLayout,
        child: ExtendedFloatingActionButton,
        directTargetChild: View,
        target: View,
        axes: Int,
        type: Int
    ): Boolean =
        axes == ViewCompat.SCROLL_AXIS_VERTICAL ||
            super.onStartNestedScroll(
                coordinatorLayout,
                child,
                directTargetChild,
                target,
                axes,
                type
            )

    override fun onNestedScroll(
        coordinatorLayout: CoordinatorLayout,
        child: ExtendedFloatingActionButton,
        target: View,
        dxConsumed: Int,
        dyConsumed: Int,
        dxUnconsumed: Int,
        dyUnconsumed: Int,
        type: Int,
        consumed: IntArray
    ) {
        super.onNestedScroll(
            coordinatorLayout,
            child,
            target,
            dxConsumed,
            dyConsumed,
            dxUnconsumed,
            dyUnconsumed,
            type,
            consumed
        )

        if (dyConsumed > 0 && child.isVisible) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            child.hide(object : ExtendedFloatingActionButton.OnChangedListener() {
                override fun onHidden(extendedFab: ExtendedFloatingActionButton?) {
                    super.onHidden(extendedFab)
                    extendedFab?.visibility = View.INVISIBLE
                }
            })
        } else if (dyConsumed < 0 && !child.isVisible) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            child.show()
        }
    }
}