How can i add custom background in BottomNavigationView

Issue

This is my xml code for bottommnavigationview

 <com.google.android.material.bottomnavigation.BottomNavigationView
    android:id="@+id/bottomNavigationView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:elevation="15dp"
    android:fitsSystemWindows="true"
    android:foreground="?attr/selectableItemBackground"
    android:visibility="visible"
    app:elevation="@dimen/margin_10dp"
    app:itemBackground="?attr/backgroundColor"
    app:itemIconSize="22dp"
    app:itemIconTint="@color/bottom_navigation_text_selector"
    app:itemTextAppearanceInactive="@style/BottomNavigation.InActiveItemTextAppearance"
    app:itemTextAppearanceActive="@style/BottomNavigation.ActiveItemTextAppearance"
    app:itemTextColor="@color/bottom_navigation_text_selector"
    app:labelVisibilityMode="labeled"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@id/container"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:menu="@menu/home_bottom_menu" />

See the red arrow i want to develop this background below my each selected item

Solution

Firstly you need to create a background drawable in drawable folder:

selected_item_background.xml

<?xml version="1.0" encoding="UTF-8"?>
<inset xmlns:android="http://schemas.android.com/apk/res/android"
    android:insetLeft="12dp"
    android:insetTop="12dp"
    android:insetRight="12dp"
    android:insetBottom="12dp"
    android:visible="true">
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/listview_background_shape">
        <corners android:radius="8dp" />
        <solid android:color="#eeeeee" />
    </shape>
</inset>

then you should create a selector in the drawable folder based on this background:

bottom_item_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/selected_item_background" android:state_checked="true" />
    <item android:drawable="@android:color/white" android:state_checked="false" />
</selector>

And then you just to need to add the attribute to your navigation view:

 <com.google.android.material.bottomnavigation.BottomNavigationView
    ...
    app:itemBackground="@drawable/bottom_item_selector"
    ...
    app:menu="@menu/home_bottom_menu" />

Answered By - Anatolii Chub