Navigation Component
Manage multi-screen navigation with a visual NavGraph, Safe Args for type-safe arguments, NavController, and deep link support.
Navigation Component is a free Android Academy lesson on CoddyKit — lesson 5 of 6. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Android Academy learning path, one of 6 lessons in the course, and your progress syncs across the web and the CoddyKit app.
What Is the Navigation Component?
The Navigation Component is an Android Jetpack library that manages fragment navigation, back stack, deep links, and transition animations in a single, visual graph.
Key benefits:
- Visual navigation graph in Android Studio
- Type-safe argument passing (Safe Args)
- Automatic back stack management
- Deep link support out of the box
Setup: Dependencies
Add to app/build.gradle:
// app/build.gradle
dependencies {
implementation 'androidx.navigation:navigation-fragment-ktx:2.7.7'
implementation 'androidx.navigation:navigation-ui-ktx:2.7.7'
}
// project/build.gradle (for Safe Args):
buildscript {
dependencies {
classpath 'androidx.navigation:navigation-safe-args-gradle-plugin:2.7.7'
}
}
// app/build.gradle — apply the plugin:
plugins {
id 'androidx.navigation.safeargs.kotlin'
}Navigation Graph (nav_graph.xml)
Create res/navigation/nav_graph.xml. It defines destinations (fragments) and actions (navigation paths):
<!-- res/navigation/nav_graph.xml -->
<navigation
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/nav_graph"
app:startDestination="@id/homeFragment">
<fragment
android:id="@+id/homeFragment"
android:name="com.example.HomeFragment">
<action
android:id="@+id/action_home_to_detail"
app:destination="@id/detailFragment" />
</fragment>
<fragment
android:id="@+id/detailFragment"
android:name="com.example.DetailFragment">
<argument
android:name="itemId"
app:argType="integer" />
</fragment>
</navigation>NavHostFragment in Activity Layout
Replace the FrameLayout container with NavHostFragment. It acts as a host for all navigation destinations:
<!-- activity_main.xml -->
<androidx.fragment.app.FragmentContainerView
android:id="@+id/navHostFragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:navGraph="@navigation/nav_graph"
app:defaultNavHost="true" />NavController — Navigating Between Fragments
Get a NavController and call navigate() with an action ID:
class HomeFragment : Fragment() {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.btnOpenDetail.setOnClickListener {
// Navigate using action ID from nav_graph
findNavController().navigate(R.id.action_home_to_detail)
}
}
}Safe Args — Type-Safe Arguments
Safe Args generates classes for passing arguments between fragments without casting or key typos:
// In HomeFragment — pass itemId:
binding.btnOpenDetail.setOnClickListener {
val action = HomeFragmentDirections.actionHomeToDetail(itemId = 42)
findNavController().navigate(action)
}
// In DetailFragment — receive itemId:
class DetailFragment : Fragment() {
private val args: DetailFragmentArgs by navArgs()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val id = args.itemId // Int, type-safe
viewModel.loadItem(id)
}
}Up Navigation
Connect the Toolbar's up button to the NavController for automatic back navigation:
class MainActivity : AppCompatActivity() {
private lateinit var navController: NavController
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val navHostFragment = supportFragmentManager
.findFragmentById(R.id.navHostFragment) as NavHostFragment
navController = navHostFragment.navController
// Wire toolbar Up button
setupActionBarWithNavController(navController)
}
override fun onSupportNavigateUp(): Boolean {
return navController.navigateUp() || super.onSupportNavigateUp()
}
}Bottom Navigation with NavController
Connect a BottomNavigationView to the NavController — it automatically handles tab selection and back stack:
// In Activity.onCreate():
val navHostFragment = supportFragmentManager
.findFragmentById(R.id.navHostFragment) as NavHostFragment
val navController = navHostFragment.navController
// Wire BottomNavigationView
binding.bottomNav.setupWithNavController(navController)
// Each menu item ID must match a fragment destination ID in nav_graph.xmlPop Back Stack
Navigate back programmatically or to a specific destination:
// Go back one step
findNavController().popBackStack()
// Navigate back to a specific destination (popping everything on top)
findNavController().popBackStack(R.id.homeFragment, inclusive = false)
// Navigate and clear back stack (e.g., after login)
findNavController().navigate(
R.id.action_login_to_home,
null,
NavOptions.Builder()
.setPopUpTo(R.id.loginFragment, inclusive = true)
.build()
)Deep Links
Add a deep link to a destination so your app can be opened from a URL:
<!-- In nav_graph.xml, inside the destination fragment: -->
<deepLink
android:id="@+id/deepLinkDetail"
app:uri="https://example.com/items/{itemId}" />
<!-- Also add intent-filter in AndroidManifest.xml for the Activity: -->
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="https" android:host="example.com" />
</intent-filter>Transitions Between Fragments
Add custom animations to navigation actions in the nav graph:
<action
android:id="@+id/action_home_to_detail"
app:destination="@id/detailFragment"
app:enterAnim="@anim/slide_in_right"
app:exitAnim="@anim/slide_out_left"
app:popEnterAnim="@anim/slide_in_left"
app:popExitAnim="@anim/slide_out_right" />Quick Check
What must match between the BottomNavigationView menu item ID and the navigation graph for automatic tab handling?
Recap: Navigation Component
Navigation Component simplifies multi-screen apps:
- Visual
nav_graph.xml— destinations + actions NavHostFragmentin Activity layoutfindNavController().navigate(actionId)to move between screens- Safe Args — type-safe argument passing (no casting, no typos)
setupActionBarWithNavController()— auto Up buttonsetupWithNavController()— auto BottomNavigationView
Next: add Dependency Injection with Hilt for clean architecture.
Frequently asked questions
Is the “Navigation Component” lesson free?
Yes — the full text of “Navigation Component” is free to read here on the web, and the Android Academy course includes 6 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Android Academy course, upgrade to CoddyKit PRO.
What will I learn in “Navigation Component”?
Manage multi-screen navigation with a visual NavGraph, Safe Args for type-safe arguments, NavController, and deep link support. You practise Android Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Android Academy?
No prior experience is required. Android Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 5 of 6, so you can start here or from the beginning and move at your own pace.
How long does the “Navigation Component” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Android Academy lesson?
Yes. Every Android Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.