PreferenceFragments not in the same FragmentManager?

Question

We have a PreferenceFragmentCompat, and with a tap on a preference, we want to switch from the current PreferenceFragmentCompat to a new PreferenceFragmentCompat. (To have certain settings on a new screen).

However, regardless of what we have tried, we keep running into the following error:

Fragment declared target fragment that does not belong to this FragmentManager

MainActivity.kt

class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsResultCallback, PreferenceFragmentCompat.OnPreferenceStartFragmentCallback {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val navView: BottomNavigationView = findViewById(R.id.nav_view)

        val navController = findNavController(R.id.nav_host_fragment)
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        val appBarConfiguration = AppBarConfiguration(
            setOf(
                R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_preferences
            )
        )

        setupActionBarWithNavController(navController, appBarConfiguration)
        navView.setupWithNavController(navController)
    }

    override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat, pref: Preference): Boolean {
        val args = pref.extras
        val fragment = supportFragmentManager.fragmentFactory.instantiate(
            classLoader,
            pref.fragment)
        fragment.arguments = args
        fragment.setTargetFragment(caller, 0)
        // Replace the existing Fragment with the new Fragment
        supportFragmentManager.beginTransaction()
            .replace(R.id.nav_host_fragment, fragment)
            .addToBackStack(null)
            .commit()
        return true
    }
}

PreferenceFragement1.kt

class PreferencesFragment1 : PreferenceFragmentCompat() {

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.preferences1, rootKey)
    }
}

PreferenceFragment2.kt

class PreferenceFragment2 : PreferenceFragmentCompat() {

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.preferences2, rootKey)
    }
}

Preferences1.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <PreferenceCategory
        android:title="Category"
        app:iconSpaceReserved="false">

        <Preference
            app:key="pref2"
            app:iconSpaceReserved="false"
            android:title="Open"
            app:fragment="com.testapp.ui.preferences.Preference2"/>

    </PreferenceCategory>
</PreferenceScreen>

Preferences2.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
</PreferenceScreen>

The stacktrace shows the following:

java.lang.IllegalStateException: Fragment Preference2{496ebb9} (1b91d8df-58c0-485a-96f9-d392fcef528b) id=0x7f09008d} declared target fragment Preference1{b6337c1} (97aa1b0e-d5fa-4995-b0ba-e89ad0ea5ce0) id=0x7f09008d} that does not belong to this FragmentManager!
        at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1148)
        at androidx.fragment.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1255)
        at androidx.fragment.app.FragmentTransition.calculateFragments(FragmentTransition.java:1138)
        at androidx.fragment.app.FragmentTransition.startTransitions(FragmentTransition.java:136)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1989)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1947)
        at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849)
        at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6718)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:491)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

We are using androidx.preference:preference-ktx:1.1.1. Can some give us a concise explanation what exactly is causing this problem, and how we can solve it?

We already looked at the following (related) posts, without any success:

score 10 · Accepted Answer · answered Aug 12 '20 at 01:48

When you create a Fragment via the navigation graph, it is a child fragment of the NavHostFragment. It specifically is not the activity's supportFragmentManager. This is why the target fragment isn't found - you're using the wrong FragmentManager.

However, you should not use app:fragment or onPreferenceStartFragment when you're using Navigation. Instead, your PreferencesFragment1 should set a click listener on your Preference and have it call navigate() directly.

class PreferencesFragment1 : PreferenceFragmentCompat() {

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.preferences1, rootKey)
        findPreference<Preference>("pref2")?.setOnPreferenceClickListener {
            // Use whatever ID that is associated with
            // PreferenceFragment2 in your navigation graph
            findNavController().navigate(R.id.pref2)
        }
    }
}

Preferences1.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <PreferenceCategory
        android:title="Category"
        app:iconSpaceReserved="false">

        <Preference
            app:key="pref2"
            app:iconSpaceReserved="false"
            android:title="Open"/>

    </PreferenceCategory>
</PreferenceScreen>

Yes, thank you for this answer! Big fan of yours by the way, as a Google employee, I wonder if the docs could be updated sometime? https://developer.android.com/guide/topics/ui/settings/organize-your-settings The overview section talks about using PreferenceFragmentCompat, from the Jetpack library, yet when we get to the above section on sub Preference Screens, we're talking about the "old" way with overriding the Activity method etc., and there's no guidance on achieving nested settings screens in Jetpack/Navigation Component world. — Vin Norman, Apr 06 '21 at 06:18
I literally searching for this answer for 3 hours. I even did some research on android sample repo https://github.com/android/user-interface-samples. Someone should put this in the official docs — Andra, Jun 29 '21 at 16:36

PreferenceFragments not in the same FragmentManager?

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