Nav Controller Queries

Nav Controller Queries

1. //automatically handles back button 
toolbar.setupWithNavController(navController)

2. //to make root fragment (or make back button gone in a particular fragment).
//This removes the back button and also disabled toolbar back button navigation (keyboard back button works)
private val rootIds = setOf(R.id.fragment1, R.id.fragment2....)
private val appBarConfiguration by lazy {AppBarConfiguration(rootIds)}
toolbar.setupWithNavController(navController,appBarConfiguration)

3. //for back button to work along with (2).
setSupportActionBar(toolbar)
setupActionBarWithNavController(navController, appBarConfiguration)

4. //Show back button on first screen itself
private val rootIds = setOf(0) //set no rootids.
private val appBarConfiguration by lazy {AppBarConfiguration(rootIds)}
setSupportActionBar(toolbar)
setupActionBarWithNavController(navController, appBarConfiguration)