Develop Reference

How to navigate from fragment to fragment within active tab

I am new to using the navigation component for Android. Most of the examples I have seen online discuss fragment navigation within an activity but, in my case, I want to navigate within a base fragment. In the picture below, I would like to navigate from a login fragment to a signup fragment within the same settings tab but am running into issues and have tried various possible solutions. Any help would be appreciated as I am aware that I can certainly missing something.
java.lang.IllegalArgumentException: Navigation action/destination com.example.animaljournalapp:id/action_userAccountFragment_to_userSignUpFragment cannot be found from the current destination Destination(com.example.animaljournalapp:id/navigation_settings) label=Settings class=com.example.animaljournalapp.ui.settings.UserAccountFragment
I attempt to perform the navigation in the login fragment file through a listener I have attached to a "Sign Up" button:
UserAccountFragment.kt
class UserAccountFragment : Fragment() {
private lateinit var userAccountModel: UserAccountModel
private lateinit var navHostFrag: Fragment
private var _binding: FragmentUserAccountBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
userAccountModel =
ViewModelProvider(this).get(UserAccountModel::class.java)
navHostFrag = SettingsMainFragment()
_binding = FragmentUserAccountBinding.inflate(inflater, container, false)
val root: View = binding.root
val loginButton: Button = root.findViewById(R.id.login_button)
val signupButton: Button = root.findViewById(R.id.signup_button)
loginButton.setOnClickListener{ view: View ->
Toast.makeText(this.context, "Hi", Toast.LENGTH_LONG).show()
}
signupButton.setOnClickListener { view: View ->
val action = UserAccountFragmentDirections.actionUserAccountFragmentToUserSignUpFragment()
Navigation.findNavController(view).navigate(action)
}
return root
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
The main activity has a navigation graph of the following:
mobile_navigation.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/mobile_navigation"
app:startDestination="#+id/navigation_home">
<fragment
android:id="#+id/navigation_home"
android:name="com.example.animaljournalapp.ui.home.HomeFragment"
android:label="#string/title_home"
tools:layout="#layout/fragment_home" />
<fragment
android:id="#+id/navigation_dashboard"
android:name="com.example.animaljournalapp.ui.dashboard.DashboardFragment"
android:label="#string/title_dashboard"
tools:layout="#layout/fragment_dashboard" />
<fragment
android:id="#+id/navigation_settings"
android:name="com.example.animaljournalapp.ui.settings.UserAccountFragment"
android:label="#string/title_settings"
tools:layout="#layout/fragment_settings_main" />
</navigation>
settings_navigation.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/settings_navigation"
app:startDestination="#id/userAccountFragment">
<fragment
android:id="#+id/userAccountFragment"
android:name="com.example.animaljournalapp.ui.settings.UserAccountFragment"
android:label="fragment_user_account"
tools:layout="#layout/fragment_user_account" >
<action
android:id="#+id/action_userAccountFragment_to_userSignUpFragment"
app:destination="#id/userSignUpFragment" />
</fragment>
<fragment
android:id="#+id/userSignUpFragment"
android:name="com.example.animaljournalapp.ui.settings.UserSignUpFragment"
android:label="UserSignUpFragment" />
</navigation>
fragment_settings_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.settings.SettingsMainFragment">
<fragment
android:id="#+id/settings_nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
app:navGraph="#navigation/settings_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>

Android: Navigation Component - How to connect Toolbar menu to the fragments?

Iv been stuck in trying to add the Navigation Component to my app. Specifically to my toolbar menu items.
I have been following the navigation migrate documentation on Android's site but I am getting a but confused on how it works or even to set it up.
This is a single-activity multi-fragment architecture.
The app would start in the MainFragment and then when tapping the menu items in the toolbar, such as Main Frag to Search Movie Frag. The user would be able to navigate using the menu items from anywhere in the app (e.g. if they click the home icon, they should be sent to the home screen form anywhere in the app. Still thinking if thats how it should be done).
The main thing is I don't know how to properly attach the Navigation Component to the menu items.
App
Nav Graph
nav_graph.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/nav_graph"
app:startDestination="#id/mainFragment">
<fragment
android:id="#+id/mainFragment"
android:name="com.example.movieapp.ui.main.MainFragment"
android:label="MainFragment">
<action
android:id="#+id/action_mainFragment_to_searchMovieFragment"
app:destination="#id/searchMovieFragment" />
</fragment>
<fragment
android:id="#+id/searchMovieFragment"
android:name="com.example.movieapp.ui.search.SearchMovieFragment"
android:label="SearchMovieFragment" />
</navigation>
main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activity.MainActivity">
<include
layout="#layout/appbar"
android:id="#+id/mainToolBar"/>
<androidx.fragment.app.FragmentContainerView
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#id/mainToolBar"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
app:navGraph="#navigation/nav_graph" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var toolbar: Toolbar
private val navController by lazy {
(supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment).navController
}
private lateinit var appBarConfiguration: AppBarConfiguration
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.main_activity)
toolbar = findViewById(R.id.mainToolBar)
setSupportActionBar(toolbar)
appBarConfiguration = AppBarConfiguration(navController.graph, null)
setupActionBarWithNavController(navController, appBarConfiguration)
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
val inflater: MenuInflater = menuInflater
inflater.inflate(R.menu.main_menu_bar, menu)
return true
}
override fun onSupportNavigateUp(): Boolean {
return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
}
}
MainFragment.kt
class MainFragment : Fragment() {
companion object {
fun newInstance() = MainFragment()
}
private lateinit var viewModel: MainViewModel
private lateinit var binding: MainFragmentBinding
private lateinit var navController: NavController
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
binding = DataBindingUtil.inflate(inflater, R.layout.main_fragment, container, false)
setHasOptionsMenu(true)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
navController = Navigation.findNavController(view)
// navController.navigate(R.id.action_mainFragment_to_searchMovieFragment)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
viewModel = ViewModelProvider(this).get(MainViewModel::class.java)
binding.viewModel = viewModel
// TODO: Use the ViewModel
}
}
main_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="viewModel"
type="com.example.movieapp.ui.main.MainViewModel" />
</data>
<LinearLayout
android:orientation="vertical"
android:id="#+id/main_fragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.MainFragment">
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MainFragment1" />
</LinearLayout>
</layout>

The id for a menu item in your file main_menu_bar.xml needs to match the id for the destination(fragment) specified in your navigation graph (nav_graph.xml).
Your main_menu_bar.xml should look something like this:
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:showIn="navigation_view">
<group android:checkableBehavior="single">
<item
android:id="#id/searchMovieFragment"
android:icon="#drawable/search"
android:title="#string/menu_search" />
<item
android:id="#id/mainFragment"
android:icon="#drawable/ic_menu_camera"
android:title="#string/menu_home" />
</group>
</menu>
Also, you need to override the onOptionsItemSelected(MenuItem) method and associate your menu items with destinations. Like so:
override fun onOptionsItemSelected(item: MenuItem): Boolean {
val navController = findNavController(R.id.nav_host_fragment)
return item.onNavDestinationSelected(navController) || super.onOptionsItemSelected(item)
}
Reference

You can add a Toolbar on top of the most basic FragmentContainerView, access this toolbar from other fragments, and change the toolbar I created separately according to the fragment in it while opening the relevant fragment as follows.
toolbar = requireActivity().findViewById(R.id.toolbar_base)
toolbar?.menu?.clear()
toolbar?.title = ""
val toolbarFlowFragment = context?.let { getInflateLayout(it, R.layout.toolbar_profile) }
toolbar?.addView(toolbarFlowFragment)

How to use global actions declared inside a nested graph from the outer graph?

I tried to use a global action using Safe Args with nested graphs but I got an error.
FragmentA.kt:
class FragmentA : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_a, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
btFragmentB.setOnClickListener {
NavHostFragment.findNavController(this)
.navigate(FragmentBDirections.actionGlobalFragmentB())
}
}
}
FragmentB.kt:
class FragmentB : Fragment()
main.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_nav_graph"
app:startDestination="#id/fragmentA">
<fragment
android:id="#+id/fragmentA"
android:name="com.cookpad.arcshowcase.stack.FragmentA"
android:label="FragmentA" />
<include app:graph="#navigation/fragment_b" />
</navigation>
fragment_b.xml
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/fragment_b"
app:startDestination="#id/fragmentB">
<fragment
android:id="#+id/fragmentB"
android:name="com.cookpad.arcshowcase.stack.FragmentB"
android:label="FragmentB" />
<action
android:id="#+id/action_global_fragmentB"
app:destination="#id/fragmentB" />
</navigation>
When I run this, I get this error: java.lang.IllegalArgumentException: navigation destination com.cookpad.arc:id/action_global_fragmentB is unknown to this NavController Which seems to indicate that the action_global_fragmentB was never merged from the sub-graph.
Is there a way to use global actions declared inside a nested graph from the outer graph?

You just need to move your global action to the main graph nav
main.xml
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_nav_graph"
app:startDestination="#id/fragmentA">
<fragment
android:id="#+id/fragmentA"
android:name="com.cookpad.arcshowcase.stack.FragmentA"
android:label="FragmentA" />
<include app:graph="#navigation/fragment_b" />
<action
android:id="#+id/action_global_fragmentB"
app:destination="#id/fragment_b" />
</navigation>
fragment_b.xml
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/fragment_b"
app:startDestination="#id/fragmentB">
<fragment
android:id="#+id/fragmentB"
android:name="com.cookpad.arcshowcase.stack.FragmentB"
android:label="FragmentB" />
</navigation>
FragmentA.kt
class FragmentA : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_a, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
btFragmentB.setOnClickListener {
NavHostFragment.findNavController(this)
.navigate(FragmentADirections.actionGlobalFragmentB())
}
}
}

Back button closes app instead of going to previous fragment android navigation component

While creating a very simple sample app, I couldn't wrap my head around why my app is closing when I press the hardware back button on my emulator.
I have 1 mainActivity and 2 fragments.
When I am on the NavigationFragment and press back, the app closes instead of going back to IntermediateFragment.
MainActivity:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
toolbar.setTitle(R.string.app_name)
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context="com.exampleapplication.MainActivity">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_constraintTop_toTopOf="parent"
/>
<fragment
android:id="#+id/my_nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
app:navGraph="#navigation/main_nav"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="#+id/toolbar"
app:layout_constraintBottom_toBottomOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
navigation_graph:
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_nav"
app:startDestination="#+id/intermediateFragment">
<fragment
android:id="#+id/intermediateFragment"
android:name="com.exampleapplication.IntermediateFragment">
<action
android:id="#+id/action_intermediate_to_navigation"
app:destination="#+id/navigationFragment"
/>
</fragment>
<fragment
android:id="#+id/navigationFragment"
android:name="com.exampleapplication.NavigationFragment"
/>
</navigation>
IntermediateFragment:
class IntermediateFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_intermediate, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
btn_next_fragment.setOnClickListener {
findNavController().navigate(R.id.action_intermediate_to_navigation)
}
}
}
NavigationFragment:
class NavigationFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_navigation, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
btn_first_library.setOnClickListener {
findNavController().setGraph(R.navigation.first_library_nav)
}
btn_download_pdf.setOnClickListener {
findNavController().setGraph(R.navigation.download_pdf_nav)
}
}
}
Any ideas?

You're missing one line on your <fragment>:
app:defaultNavHost="true"
As per the Navigation Getting Started guide:
The app:defaultNavHost="true" attribute ensures that your NavHostFragment intercepts the system Back button.
Since you don't set that, Navigtion does not intercept the back button and hence, you only get the default activity behavior (which is closing your activity).

Jetpack navigation does not navigate to other destination

I am using jetpack navigation in two different activities each with its navigation host. I have Main activity which everything just works fine and Setup activity which have 2 fragments, one has a button which should navigate to other fragment when clicked .
The activity's code is as follows:
class SetupActivity : AppCompatActivity() {
private val navController by lazy { findNavController(R.id.nav_host_fragment) }
private lateinit var appBarConfig: AppBarConfiguration
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
DataBindingUtil.setContentView<ActivitySetupBinding>(this, R.layout.activity_setup)
setSupportActionBar(toolbar)
appBarConfig = AppBarConfiguration(navController.graph)
setupActionBarWithNavController(navController, appBarConfig)
}
override fun onSupportNavigateUp(): Boolean {
return navController.navigateUp(appBarConfig) || super.onSupportNavigateUp()
}
}
Below is activity's xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".ui.SetupActivity"
tools:showIn="#layout/activity_setup">
<fragment
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="#navigation/setup" />
</androidx.constraintlayout.widget.ConstraintLayout>
Below is code of first fragment which is also a start Destination
class ConfirmClassFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val binding = FragmentConfirmClassBinding.inflate(inflater, container, false)
binding.fragment = this
return binding.root
}
fun navigate() {
toast("clicked") //this get called
val direction = ConfirmClassFragmentDirections.actionConfirmToSetup()
findNavController().navigate(direction) //THE PROBLEM IS HERE
//findNavController().navigate(R.id.setup)
}
}
I am using data binding to call fun navigate() as below:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="fragment"
type="com.nux.ui.fragments.ConfirmClassFragment" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="#dimen/spacing_middle">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="#{() -> fragment.navigate()}"
android:text="#string/continue_" />
</LinearLayout>
</layout>
and this how navigation xml looks like:
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/setup"
app:startDestination="#id/confirm">
<fragment
android:id="#+id/setup"
android:name="com.nux.ui.fragments.SetInfoFragment"
android:label="#string/setup"
tools:layout="#layout/fragment_set_info" />
<fragment
android:id="#+id/confirm"
android:name="com.nux.ui.fragments.ConfirmClassFragment"
android:label="#string/data_confirmation"
tools:layout="#layout/fragment_confirm_class">
<action
android:id="#+id/action_confirm_to_setup"
app:destination="#id/setup" />
</fragment>
</navigation>
When I click button fun gets called but nothing happens! What could be wrong?

From the code i can see you have the same id for 3 elements in the navigation graph.
#id/setup should only be used once and please change the name of the navigation graph from setup to something else.