{"@context":"https://schema.org","@type":"FAQPage","mainEntity":[{"@type":"Question","name":"What is Jetpack's Navigation Component?","acceptedAnswer":{"@type":"Answer","text":"Navigation Component is a Jetpack library that simplifies navigation between destinations (fragments/activities). It offers automatic back stack management, SafeArgs for type-safe arguments, navigation graph visualization, and handles deep links. It's Google's recommended solution for navigation in modern Android apps."}},{"@type":"Question","name":"What is a Navigation Graph?","acceptedAnswer":{"@type":"Answer","text":"A Navigation Graph is an XML file (stored in res/navigation/) that visually defines all navigation destinations (fragments, activities) and transition actions between them. It allows visualizing the app's navigation flow and defines arguments passed between destinations. It's the central file of Navigation Component."}},{"@type":"Question","name":"What is the NavController?","acceptedAnswer":{"@type":"Answer","text":"NavController is the central object that manages navigation within a NavHost. It allows navigating between destinations (navigate()), going back (popBackStack()), and managing the back stack. It's obtained via findNavController() from a Fragment or Navigation.findNavController(view). It executes actions defined in the Navigation Graph."}},{"@type":"Question","name":"What is the NavHost?","acceptedAnswer":{"@type":"Answer","text":"NavHost is an empty container (typically a FragmentContainerView) that displays destinations from the Navigation Graph. It hosts the NavController and changes its content during navigation. It's configured in XML with app:navGraph and app:defaultNavHost='true' to automatically handle the back button."}},{"@type":"Question","name":"How to navigate to a destination with NavController?","acceptedAnswer":{"@type":"Answer","text":"To navigate, use findNavController().navigate(R.id.action_or_destination) passing either an action ID defined in the graph or directly the destination ID. Arguments can be added via a Bundle or using SafeArgs for more safety. The navigate() method automatically manages the back stack."}},{"@type":"Question","name":"What is SafeArgs?","acceptedAnswer":{"@type":"Answer","text":"SafeArgs is a Gradle plugin (androidx.navigation.safeargs.kotlin) that generates type-safe classes for passing arguments between destinations. Instead of using manual Bundles, use generated classes like HomeFragmentDirections.actionToDetail(userId = 123). This prevents typing errors and incorrect keys. Arguments are defined in the Navigation Graph with ."}},{"@type":"Question","name":"How to retrieve arguments in a destination with SafeArgs?","acceptedAnswer":{"@type":"Answer","text":"In the destination fragment, use the by navArgs() delegate with the class generated by SafeArgs: val args: DetailFragmentArgs by navArgs(). You can then access arguments in a type-safe way: args.userId, args.userName. This approach is safer than manually retrieving from arguments?."}},{"@type":"Question","name":"What is a Deep Link in Navigation Component?","acceptedAnswer":{"@type":"Answer","text":"A Deep Link is a URI that allows directly opening a specific destination in the app. They're defined in the Navigation Graph with . Navigation Component automatically handles intents with these URIs. You must add in the Manifest to enable deep links."}},{"@type":"Question","name":"How to integrate BottomNavigationView with Navigation Component?","acceptedAnswer":{"@type":"Answer","text":"Create a menu with items having the same IDs as graph destinations, then use setupWithNavController(): bottomNav.setupWithNavController(navController). Synchronization is automatic: selecting an item navigates to the destination, changing destination updates the selected item. Back stack is managed intelligently."}},{"@type":"Question","name":"How to integrate a NavigationDrawer with Navigation Component?","acceptedAnswer":{"@type":"Answer","text":"Use AppBarConfiguration with top-level destinations and DrawerLayout: val appBarConfig = AppBarConfiguration(setOf(R.id.home, R.id.settings), drawerLayout). Then setupActionBarWithNavController(navController, appBarConfig) and navView.setupWithNavController(navController). The drawer closes automatically during navigation."}},{"@type":"Question","name":"What's the difference between the Back button (system) and the Up button (Toolbar)?","acceptedAnswer":{"@type":"Answer","text":"The Back button (system) navigates through chronological back stack history and can exit the app. The Up button (Toolbar) navigates hierarchically to the parent defined in the graph and stays within the app. AppBarConfiguration defines top-level destinations that don't show the Up button."}},{"@type":"Question","name":"What is the popUpTo attribute used for in an action?","acceptedAnswer":{"@type":"Answer","text":"popUpTo cleans the back stack before navigating. For example, app:popUpTo='@id/login' app:popUpToInclusive='true' in an action to home removes login and everything above it from the back stack. This prevents returning to the login screen with the back button after successful login."}},{"@type":"Question","name":"What does the popBackStack() method do?","acceptedAnswer":{"@type":"Answer","text":"popBackStack() removes the current destination from the back stack and returns to the previous one. It returns true if successful, false if the back stack is empty. Variant: popBackStack(destinationId, inclusive) removes all destinations up to destinationId. It's useful for closing a screen after a successful action."}},{"@type":"Question","name":"What is a Global Action?","acceptedAnswer":{"@type":"Answer","text":"A Global Action is an action defined directly under (not under a fragment) that's accessible from any destination in the graph. Example: . Useful for navigating to settings or profile from anywhere."}},{"@type":"Question","name":"How to pass dynamic arguments via a Deep Link?","acceptedAnswer":{"@type":"Answer","text":"Use placeholders in the URI: with a corresponding argument . The argument is automatically extracted from the URL. You can also use query parameters: myapp://product?id={productId}."}},{"@type":"Question","name":"What is the launchSingleTop option?","acceptedAnswer":{"@type":"Answer","text":"launchSingleTop prevents creating a new instance if the destination is already on top of the back stack. Configuration: app:launchSingleTop='true' in the graph or NavOptions.setLaunchSingleTop(true). If navigating to DetailFragment that's already on top, no new instance but arguments are updated."}},{"@type":"Question","name":"How to listen to destination changes?","acceptedAnswer":{"@type":"Answer","text":"Use OnDestinationChangedListener: navController.addOnDestinationChangedListener { controller, destination, arguments -> ... }. You receive the destination's ID and label. Useful for showing/hiding bottom nav based on destination, analytics, etc. Important: unsubscribe to avoid memory leaks."}},{"@type":"Question","name":"What is a Nested Navigation Graph?","acceptedAnswer":{"@type":"Answer","text":"A Nested Navigation Graph is a subgraph nested within another graph. It allows modularizing navigation: grouping related screens (e.g., authentication flow login/register/forgot), encapsulating internal details, and reusing the subgraph. You navigate to the nested graph like a normal destination."}},{"@type":"Question","name":"How to configure transition animations?","acceptedAnswer":{"@type":"Answer","text":"Define in action: app:enterAnim='@anim/slide_in_right' app:exitAnim='@anim/slide_out_left' app:popEnterAnim='@anim/slide_in_left' app:popExitAnim='@anim/slide_out_right'. enterAnim: entering destination, exitAnim: exiting destination, popEnterAnim: return animation, popExitAnim: disappearing animation on return."}},{"@type":"Question","name":"What argument types are supported by SafeArgs?","acceptedAnswer":{"@type":"Answer","text":"Primitive types: integer, long, float, boolean, string. Android types: reference (resource ID). Custom types: Parcelable, Serializable, Enum. Arrays: integer[], string[]. Nullable: app:nullable='true'. Configuration: app:argType='integer' or app:argType='com.example.User' for a Parcelable."}},{"@type":"Question","name":"How to get the current destination from NavController?","acceptedAnswer":{"@type":"Answer","text":"Use navController.currentDestination which returns a NavDestination? with properties id, label, navigatorName. Or navController.currentBackStackEntry?.destination. Useful for checking where we are before navigating, conditionally show/hide UI, analytics, debugging."}},{"@type":"Question","name":"Can you have multiple NavHostFragments in an Activity?","acceptedAnswer":{"@type":"Answer","text":"Yes, it's possible but rare. Use case: list-detail screen on tablet, two independent panels with their navigation. Each NavHostFragment has its own NavController and back stack. Configuration: two FragmentContainerView with different IDs and navGraphs. For most apps, one is enough."}},{"@type":"Question","name":"How to navigate to another Activity with Navigation Component?","acceptedAnswer":{"@type":"Answer","text":"Define an destination in the graph: . Navigation: findNavController().navigate(R.id.secondActivity). However, Navigation Component favors single-activity architecture with fragments. Classic Intents remain valid for true Activity separations."}},{"@type":"Question","name":"How to define a default value for an argument?","acceptedAnswer":{"@type":"Answer","text":"Use app:defaultValue in : . With SafeArgs, the argument becomes optional: HomeFragmentDirections.actionToDetail() uses 0, or actionToDetail(userId = 123) passes 123. Avoids always having to pass all arguments."}},{"@type":"Question","name":"What is NavOptions and what is it used for?","acceptedAnswer":{"@type":"Answer","text":"NavOptions allows configuring navigation programmatically: NavOptions.Builder().setLaunchSingleTop(true).setEnterAnim(...).setPopUpTo(...).build(). Pass it to navigate(destination, bundle, navOptions). Allows controlling animations, popUpTo, launchSingleTop, saveState/restoreState without defining them in XML."}},{"@type":"Question","name":"What's the main advantage of Navigation Component vs Intents?","acceptedAnswer":{"@type":"Answer","text":"Automatic back stack management, type-safe arguments with SafeArgs, navigation flow visualization, integrated deep links, native Bottom Nav and Drawer support, single-activity architecture, testability. Intents remain useful for navigating to other apps or system components. Navigation Component greatly simplifies internal navigation."}}]}