How to make bottom nav view items reselectable? Android

Question

For some reason i can't reselect items in my bottom nav view. How can i enable this feauture?

I have 3 top destination fragments (bottom nav view items): A, B, C

App structure looks like this:

A -> A1

B -> B1 -> B2

C

When user is at fragment B2 he should be able to reselect currently active item, and open fragment B.

Here is related code snippets:

mainActivity.kt

val navView: BottomNavigationView = binding.navView
val navController = findNavController(R.id.nav_host_fragment_activity_main)
val appBarConfiguration = AppBarConfiguration(
    setOf(
        R.id.graph_profile, R.id.graph_tools_library,
        R.id.graph_settings
    )
)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(
    navController)

mobile_navigation.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/mobile_navigation"
    app:startDestination="@id/graph_profile">

    <navigation
        android:id="@+id/graph_profile"
        app:startDestination="@id/navigation_profile">
        <fragment
            android:id="@+id/navigation_profile"
            android:name="com.example.pocketpsy.presentation.profile.ProfileFragment"
            android:label="@string/profile"
            tools:layout="@layout/fragment_profile">
            <action
                android:id="@+id/navigate_to_results"
                app:destination="@id/navigation_results" />
        </fragment>
        <fragment
            android:id="@+id/navigation_results"
            android:name="com.example.pocketpsy.presentation.results.ResultsFragment"
            android:label="@string/results">
            <argument
                android:name="resultsID"
                app:argType="string" />
        </fragment>
    </navigation>

    <navigation
        android:id="@+id/graph_tools_library"
        app:startDestination="@id/navigation_tools_library">
        <fragment
            android:id="@+id/navigation_tools_library"
            android:name="com.example.pocketpsy.presentation.toolslibrary.ToolsLibraryFragment"
            android:label="@string/tools_library"
            tools:layout="@layout/fragment_tools_library">
            <action
                android:id="@+id/navigate_to_description"
                app:destination="@id/navigation_description" />
            <action
                android:id="@+id/navigate_to_tool"
                app:destination="@id/navigation_tool" />
        </fragment>
        <fragment
            android:id="@+id/navigation_description"
            android:name="com.example.pocketpsy.presentation.description.DescriptionFragment">
            <argument
                android:name="toolID"
                app:argType="string" />
            <action
                android:id="@+id/navigate_to_tool"
                app:destination="@id/navigation_tool"
                app:popUpTo="@id/navigation_tools_library" />
        </fragment>
        <fragment
            android:id="@+id/navigation_tool"
            android:name="com.example.pocketpsy.presentation.tool.ToolFragment"
            android:label="@string/tool"
            tools:layout="@layout/fragment_tool">
            <argument
                android:name="toolID"
                app:argType="string" />
            <action
                android:id="@+id/navigate_to_results"
                app:destination="@id/navigation_results" />
        </fragment>
        <fragment
            android:id="@+id/navigation_results"
            android:name="com.example.pocketpsy.presentation.results.ResultsFragment"
            android:label="@string/results">
            <argument
                android:name="resultsID"
                app:argType="string" />
        </fragment>
    </navigation>

    <navigation
        android:id="@+id/graph_settings"
        app:startDestination="@id/navigation_settings">
        <fragment
            android:id="@+id/navigation_settings"
            android:name="com.example.pocketpsy.presentation.settings.SettingsFragment"
            android:label="fragment_settings"
            tools:layout="@layout/fragment_settings" />
    </navigation>

</navigation>

bottom_nav_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <item
        android:id="@+id/graph_profile"
        android:icon="@drawable/ic_bottom_bar_profile"
        android:title="A" />

    <item
        android:id="@+id/graph_tools_library"
        android:icon="@drawable/ic_bottom_bar_tools_library"
        android:title="B"/>

    <item
        android:id="@+id/graph_settings"
        android:icon="@drawable/ic_bottom_bar_settings"
        android:title="C" />

</menu>

Answer 1

if you want to unselect specific manu item in nav View the use

navigationView.getMenu().getItem(3).setChecked(false);

if use this in mainActivity or homeactivity and on position 0 item then on start of app there is no menu selected by default