Android Navigation Architecture Component - Get current visible fragment

Question

Before trying the Navigation component I used to manually do fragment transactions and used the fragment tag in order to fetch the current fragment.

val fragment:MyFragment = supportFragmentManager.findFragmentByTag(tag):MyFragment

Now in my main activity layout I have something like:

<fragment
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/nav_host"
        app:navGraph= "@navigation/nav_item"
        android:name="androidx.navigation.fragment.NavHostFragment"
        app:defaultNavHost= "true"
        />

How can I retrieve the current displayed fragment by the Navigation component? Doing

supportFragmentManager.findFragmentById(R.id.nav_host)

returns a NavHostFragment and I want to retrieve my shown 'MyFragment`.

Thank you.

Answer 1

I managed to discover a way for now and it is as follows:

NavHostFragment navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host);
navHostFragment.getChildFragmentManager().getFragments().get(0);

In case of course you know it is the first fragment. I am still investigating a way without this. I agree it is not the best way but that should be something for now.

Answer 2

There is no way I can find to retrieve the current fragment instance. However, you can get the ID of lastly added fragment using the code below.

navController.currentDestination?.getId()

It returns the ID in navigation file. Hope this helps.

Answer 3

You should look the childFragmentManager primaryNavigationFragment property of your nav fragment, this is where the current displayed fragment is referenced.

val navHost = supportFragmentManager.findFragmentById(R.id.main_nav_fragment)
    navHost?.let { navFragment ->
        navFragment.childFragmentManager.primaryNavigationFragment?.let {fragment->
                //DO YOUR STUFF
        }
    }
}

Answer 4

This seems like the cleanest solution. Update: Changed extension function to property. Thanks Igor Wojda.

1. Create the following extension

import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentManager

val FragmentManager.currentNavigationFragment: Fragment?
    get() = primaryNavigationFragment?.childFragmentManager?.fragments?.first()

2. In Activity with NavHostFragment use it like this:

val currentFragment = supportFragmentManager.currentNavigationFragment