Restore menu items states using Navigation with BottomNavigationView + FloatingActionButton (FAB)

Question

How can I setupWithNavController my BottomNavigationView with a FloatingActionButton (FAB) on top?

Thanks StackOverflow for hating me and not letting me display photos. :)

According to the Navigation library releases…

Starting in Navigation 2.4.0-alpha01, the state of each menu item is saved and restored when you use setupWithNavController.

This works like a charm, however, when I setup my BottomNavigationView and press the FAB, the states of the current menu items are reloaded. How can I achieve the same behavior of clicking on any menu item with the FAB?

binding.activityMainBottomNavigationView.setupWithNavController(navController)

binding.activityMainFloatingActionButton.setOnClickListener {

    // TODO: Fix navigation.
    navController.navigate(R.id.homeFragment)

    binding.activityMainBottomNavigationView.selectedItemId = R.id.homeFragment      
}

As I understand, calling navController.navigate() may be resetting the current nav_graph used by the fragmentContainerView and that's why the current menu items are being reloaded. Is there any way to avoid this?

Answer 1

After a week of several attempts, I achieved the desired purpose using onNavDestinationSelected from NavigationUI.

binding.activityMainBottomNavigationView.setupWithNavController(navController)

binding.activityMainFloatingActionButton.setOnClickListener {

    NavigationUI.onNavDestinationSelected(
        binding.activityMainBottomNavigationView.menu.findItem(R.id.homeFragment),
        navController
    )

    binding.activityMainBottomNavigationView.selectedItemId = R.id.homeFragment
}

In this way, the states of the fragments and navigation survive! 🤠

Cheers! 🍾