How to hide the FloatingActionButton that is part of the Activity in the Fragment in Kotlin?

Question

In my 'HomeActivity', I have a FloatingActionButton and four Fragments. I want the FloatingActionButton to be shown only in the 'fragment1' and 'fragment2' make hide it in the 'fragment3' and 'fragment4'. I tried but it didn't work.

Following is what I have in the xml file of the 'HomeActivity'

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.bottomappbar.BottomAppBar
        android:id="@+id/bottom_appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom">

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/nav_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginEnd="16dp"
            android:background="@android:color/transparent"
            app:menu="@menu/bottom_nav_menu" />

    </com.google.android.material.bottomappbar.BottomAppBar>

        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/fab_one"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/ic_hide_category"
            app:layout_anchor="@id/bottom_appbar"/>

    <fragment
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="50dp"
        app:defaultNavHost="true"
        app:navGraph="@navigation/mobile_navigation"
        app:layout_anchor="@id/bottom_appbar"/>

</androidx.coordinatorlayout.widget.CoordinatorLayout>

I added the below code in the 'HomeActivity'

fun hideFabOne(){
    binding.fabOne.hide()
}

and below code in the onCreateView of the fragments where I want to hide the FAB. But, it didn't work.

HomeActivity().hideFabOne()

Answer 1

Looks like you are creating new instance of activity , try

(requireActivity() as HomeActivity).hideFabOne()

*Add for comment You can modify the hideFabOne() something like

fun hideFabOne(){
    binding.fabOne.visiblity = if( binding.fabOne.isVisible ) View.VISIBLE else View.GONE
}