How to configure the Drawer Navigation button when not using the start as the top-level navigation?

Issue

I'm using the navigation graph to navigate and have a start screen (splash fragment) as the first fragment that is shown. The issue is that when I go to the main fragment/screen the top navigation button shows back instead of the drawer icon. How can we get control over this? What are some options. How can I change the start destination? (if possible)

When the user is at a top-level destination, the Navigation button becomes a drawer icon if the destination uses a DrawerLayout. If the destination doesn't use a DrawerLayout, the Navigation button is hidden. When the user is on any other destination, the Navigation button appears as an Up button . To configure the Navigation button using only the start destination as the top-level destination, create an AppBarConfiguration object, and pass in the corresponding navigation graph, as shown below:

Example Code

My issue is that the back button is still present when navigating to next_fragment. It should show the menu/hamburger icon.

class MainActivity : AppCompatActivity() {

private lateinit var drawerLayout: DrawerLayout
private lateinit var appBarConfiguration : AppBarConfiguration

override fun onCreate(savedInstanceState: Bundle?) {

    super.onCreate(savedInstanceState)

    val binding = DataBindingUtil.setContentView<ActivityMainBinding>(this, R.layout.activity_main)
    drawerLayout = binding.drawerLayout

    val navController = this.findNavController(R.id.mainNavigationHostFragment)
    NavigationUI.setupActionBarWithNavController(this, navController)

    appBarConfiguration = AppBarConfiguration(setOf(R.id.nextFragment), drawerLayout) 
    NavigationUI.setupWithNavController(binding.mainNavigationDrawerView, navController)

    val navigationHeader = binding.mainNavigationDrawerView.getHeaderView(0)
    val iconButton = navigationHeader.findViewById<ImageButton>(R.id.main_nav_icon_button)
    

}

override fun onSupportNavigateUp(): Boolean {

    val navController = this.findNavController(R.id.mainNavigationHostFragment)
    return NavigationUI.navigateUp(navController, appBarConfiguration)
}

}

Solution

Instead of passing Navigation Graph to AppbarConfiguration, pass the id of the Fragment that should show the HamBurger icon, that way when the particular Fragment is shown, it shows home/hamburger icon instead of back icon.

That is

val appBarConfiguration = AppBarConfiguration(setOf(R.id.FAGMENT_THAT_SHOULD_SHOW_HOME_ICON), DRAWER_LAYOUT)

Update

Instead of

val navController = this.findNavController(R.id.mainNavigationHostFragment)

NavigationUI.setupActionBarWithNavController(this, navController) 

 appBarConfiguration = AppBarConfiguration(setOf(R.id.nextFragment), drawerLayout) 
    NavigationUI.setupWithNavController(binding.mainNavigationDrawerView, navController)

val navigationHeader = binding.mainNavigationDrawerView.getHeaderView(0)
  val iconButton = navigationHeader.findViewById<ImageButton>(R.id.main_nav_icon_button)
    

Just

val navController = this.findNavController(R.id.mainNavigationHostFragment)

appBarConfiguration = AppBarConfiguration(setOf(R.id.nextFragment), drawerLayout) 
    

NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);

Answered By - Debarshi Bhattacharjee