android navigation graph configration change

Question

I am trying to follow single activity pattern with android navigation component and my %99 of fragment are portrait but I need to make a new fragment can be portrait or landscape without adding new activity how can I achieve. I could't find any resource. is it possible ? if it is how ?

Answer 1

You can add NavController.OnDestinationChangedListener and set orientation according to the current fragment.

Add this in your activity's onCreate:

val navHostFragment = supportFragmentManager.findFragmentById(R.id.your_nav_host_fragment) as NavHostFragment
navHostFragment.navController..addOnDestinationChangedListener { _, destination, _ ->
    if (destination.id == R.id.destination_with_orientation) {
        requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_SENSOR
    } else {
        requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
    }
}

Answer 2

The following steps could be useful for you:

1. Don't lock screen orientation from AndroidManifest.xml.

2. Register a listener inside Activity on the childFragmentManager of the NavHostFragment, that will execute callbacks on fragment lifecycle change

override fun onCreate(savedInstanceState: Bundle?) {
   //...
   
   val fragments = supportFragmentManager.fragments
   check(fragments.size == 1) {
       val baseMessage = "Expected 1 fragment to host the app's navigation. Instead found ${fragments.size}."
       if (fragments.size == 0) {
           val suggestion = "(Make sure you specify `android:name=\"androidx.navigation.fragment." +
                   "NavHostFragment\"` or override setUpNavigationGraph)"
           "$baseMessage $suggestion"

       } else baseMessage
   }

   with(fragments[0].childFragmentManager) {
       registerFragmentLifecycleCallbacks(CustomFragmentLifecycleCallbacks(), false)
   }
}

private inner class CustomFragmentLifecycleCallbacks : FragmentManager.FragmentLifecycleCallbacks() {
   override fun onFragmentViewCreated(fm: FragmentManager, f: Fragment, v: View, savedInstanceState: Bundle?) {}
   override fun onFragmentViewDestroyed(fm: FragmentManager, f: Fragment) {}
}

3. Follow this guide to lock/unlock screen orientation depending upon which Fragment is visible, from the above callback.

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NOTE

Fragment tags or instance type could be used for writing conditional statements inside the lifecycle callbacks, based on app's navigation design.

Don't forget to unregisterFragmentLifecycleCallbacks from Activity.onDestroy()

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Cheers