Dialog destinations

In Android navigation, the term dialog destination refers to destinations within the app's navigation graph which take the form of dialog windows, overlaying app UI elements and content.

Because dialog destinations appear over hosted destinations that fill the navigation host, there are some important considerations regarding how dialog destinations interact with your NavController's back stack.

Dialog composable

To create a dialog destination in Compose, add a destination to your NavHost using the dialog() function. The function behaves essentially the same as composable, only it creates a dialog destination rather than a hosted destination.

Consider the following example:

@Serializable
object Home
@Serializable
object Settings
@Composable
fun HomeScreen(onNavigateToSettings: () -> Unit){
    Column {
        Text("Home")
        Button(onClick = onNavigateToSettings){
            Text("Open settings")
        }
    }
}

// This screen will be displayed as a dialog
@Composable
fun SettingsScreen(){
    Text("Settings")
    // ...
}

@Composable
fun MyApp() {
    val navController = rememberNavController()
    NavHost(navController, startDestination = Home) {
        composable<Home> { HomeScreen(onNavigateToSettings = { navController.navigate(route = Settings) }) }
        dialog<Settings> { SettingsScreen() }
    }
}

1. The start destination uses the Home route. Because composable() adds it to the graph, it is a hosted destination.
2. The other destination uses the Settings route.
   • Similarly, because dialog() adds it to the graph, it is a dialog destination.
   • When the user navigates from HomeScreen to SettingsScreen the latter appears over HomeScreen.
3. Although SettingsScreen doesn't include a Dialog composable itself, because it is a dialog destination, the NavHost displays it within a Dialog.

Dialog destinations appear over the previous destination in the NavHost. Use them when the dialog represents a separate screen in your app that needs its own lifecycle and saved state, independent of any other destination in your navigation graph. You might prefer to use an AlertDialog or related composable if you want a dialog for a less complex prompt, such as a confirmation.

Kotlin DSL

If you are working with fragments and you are using the Kotlin DSL to create your graph, adding a dialog destination is very similar to when using Compose.

Consider how in the following snippet also uses the dialog() function to add a dialog destination that uses a fragment:

// Define destinations with serializable classes or objects
@Serializable
object Home
@Serializable
object Settings

// Add the graph to the NavController with `createGraph()`.
navController.graph = navController.createGraph(
    startDestination = Home
) {
    // Associate the home route with the HomeFragment.
    fragment<HomeFragment, Home> {
        label = "Home"
    }

    // Define the settings destination as a dialog using DialogFragment.
    dialog<SettingsFragment, Settings> {
        label = "Settings"
    }
}

XML

If you have an existing DialogFragment, use the <dialog> element to add the dialog to your navigation graph, as shown in the following example:

<?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/nav_graph">

...

<dialog
    android:id="@+id/my_dialog_fragment"
    android:name="androidx.navigation.myapp.MyDialogFragment">
    <argument android:name="myarg" android:defaultValue="@null" />
        <action
            android:id="@+id/myaction"
            app:destination="@+id/another_destination"/>
</dialog>

...

</navigation>