You can include an Android View hierarchy in a Compose UI. This approach is
particularly useful if you want to use UI elements that are not yet available in
Compose, like
[`AdView`](https://developers.google.com/android/reference/com/google/android/gms/ads/AdView).
This approach also lets you reuse custom views you may have designed.

To include a view element or hierarchy, use the [`AndroidView`](https://developer.android.com/reference/kotlin/androidx/compose/ui/viewinterop/package-summary#AndroidView(kotlin.Function1,androidx.compose.ui.Modifier,kotlin.Function1))
composable. `AndroidView` is passed a lambda that returns a
[`View`](https://developer.android.com/reference/android/view/View). `AndroidView` also provides an `update`
callback that is called when the view is inflated. The `AndroidView` recomposes
whenever a `State` read within the callback changes. `AndroidView`, like many
other built-in composables, takes a `Modifier` parameter that can be used, for
example, to set its position in the parent composable.


```kotlin
@Composable
fun CustomView() {
    var selectedItem by remember { mutableIntStateOf(0) }

    // Adds view to Compose
    AndroidView(
        modifier = Modifier.fillMaxSize(), // Occupy the max size in the Compose UI tree
        factory = { context ->
            // Creates view
            MyView(context).apply {
                // Sets up listeners for View -> Compose communication
                setOnClickListener {
                    selectedItem = 1
                }
            }
        },
        update = { view ->
            // View's been inflated or state read in this block has been updated
            // Add logic here if necessary

            // As selectedItem is read here, AndroidView will recompose
            // whenever the state changes
            // Example of Compose -> View communication
            view.selectedItem = selectedItem
        }
    )
}

@Composable
fun ContentExample() {
    Column(Modifier.fillMaxSize()) {
        Text("Look at this CustomView!")
        CustomView()
    }
}
```

<br />

| **Note:** Prefer to construct a View in the `AndroidView` `factory` lambda instead of using `remember` to hold a View reference outside of `AndroidView`.

## `AndroidView` with view binding

To embed an XML layout, use the
[`AndroidViewBinding`](https://developer.android.com/reference/kotlin/androidx/compose/ui/viewinterop/package-summary#AndroidViewBinding(kotlin.Function3,%20androidx.compose.ui.Modifier,%20kotlin.Function1))
API, which is provided by the `androidx.compose.ui:ui-viewbinding` library. To
do this, your project must enable [view binding](https://developer.android.com/topic/libraries/view-binding#setup).


```kotlin
@Composable
fun AndroidViewBindingExample() {
    AndroidViewBinding(ExampleLayoutBinding::inflate) {
        exampleView.setBackgroundColor(Color.GRAY)
    }
}
```

<br />

## `AndroidView` in Lazy lists

If you are using an `AndroidView` in a Lazy list (`LazyColumn`, `LazyRow`,
`Pager`, etc.), consider using the [`AndroidView`](https://developer.android.com/reference/kotlin/androidx/compose/ui/viewinterop/package-summary#AndroidView(kotlin.Function1,kotlin.Function1,androidx.compose.ui.Modifier,kotlin.Function1,kotlin.Function1))
overload introduced in version 1.4.0-rc01. This overload allows Compose to reuse
the underlying `View` instance when the containing composition is reused as is
the case for Lazy lists.

This overload of `AndroidView` adds 2 additional parameters:

- `onReset` - A callback invoked to signal that the `View` is about to be reused. This must be non-null to enable View reuse.
- `onRelease` (optional) - A callback invoked to signal that the `View` has exited the composition and will not be reused again.


```kotlin
@Composable
fun AndroidViewInLazyList() {
    LazyColumn {
        items(100) { index ->
            AndroidView(
                modifier = Modifier.fillMaxSize(), // Occupy the max size in the Compose UI tree
                factory = { context ->
                    MyView(context)
                },
                update = { view ->
                    view.selectedItem = index
                },
                onReset = { view ->
                    view.clear()
                }
            )
        }
    }
}
```

<br />

## Fragments in Compose

Use the `AndroidFragment` composable to add a `Fragment` in Compose.
`AndroidFragment` has fragment-specific handling such as removing the
fragment when the composable leaves the composition.

To include a fragment, use the [`AndroidFragment`](https://developer.android.com/reference/kotlin/androidx/fragment/compose/package-summary#AndroidFragment)
composable. You pass a `Fragment` class to `AndroidFragment`, which then adds
an instance of that class directly into the composition. `AndroidFragment` also
provides a `fragmentState` object to create the `AndroidFragment` with a given
state, `arguments` to pass into the new fragment, and an `onUpdate` callback
that provides the fragment from the composition. Like many
other built-in composables, `AndroidFragment` accepts a `Modifier` parameter
that you can use, for
example, to set its position in the parent composable.

Call `AndroidFragment` in Compose as follows:


```kotlin
@Composable
fun FragmentInComposeExample() {
    AndroidFragment<MyFragment>()
}
```

<br />

## Calling the Android framework from Compose

Compose operates within the Android framework classes. For example, it's hosted
on Android View classes, like `Activity` or `Fragment`, and might use Android
framework classes like the `Context`, system resources,
`Service`, or `BroadcastReceiver`.

To learn more about system resources, see [Resources in Compose](https://developer.android.com/develop/ui/compose/resources).

### Composition Locals

[`CompositionLocal`](https://developer.android.com/reference/kotlin/androidx/compose/runtime/CompositionLocal)
classes allow passing data implicitly through composable functions. They're
usually provided with a value in a certain node of the UI tree. That value can
be used by its composable descendants without declaring the `CompositionLocal`
as a parameter in the composable function.

`CompositionLocal` is used to propagate values for Android framework types in
Compose such as `Context`, `Configuration` or the `View` in which the Compose
code is hosted with the corresponding
[`LocalContext`](https://developer.android.com/reference/kotlin/androidx/compose/ui/platform/package-summary#LocalContext()),
[`LocalConfiguration`](https://developer.android.com/reference/kotlin/androidx/compose/ui/platform/package-summary#LocalConfiguration()),
or
[`LocalView`](https://developer.android.com/reference/kotlin/androidx/compose/ui/platform/package-summary#LocalView()).
Note that `CompositionLocal` classes are prefixed with `Local` for better
discoverability with auto-complete in the IDE.

Access the current value of a `CompositionLocal` by using its `current`
property. For example, the code below shows a toast message by providing
`LocalContext.current` into the `Toast.makeToast` method.


```kotlin
@Composable
fun ToastGreetingButton(greeting: String) {
    val context = LocalContext.current
    Button(onClick = {
        Toast.makeText(context, greeting, Toast.LENGTH_SHORT).show()
    }) {
        Text("Greet")
    }
}
```

<br />

For a more complete example, take a look at the [Case Study:
BroadcastReceivers](https://developer.android.com/develop/ui/compose/migrate/interoperability-apis/views-in-compose#case-study-broadcastreceivers) section at the end of this
document.

## Other interactions

If there isn't a utility defined for the interaction you need, the best practice
is to follow the general Compose guideline,
*data flows down, events flow up* (discussed at more length in [Thinking
in Compose](https://developer.android.com/develop/ui/compose/mental-model)). For example, this composable
launches a different activity:


```kotlin
class OtherInteractionsActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // get data from savedInstanceState
        setContent {
            MaterialTheme {
                ExampleComposable(data, onButtonClick = {
                    startActivity(Intent(this, MyActivity::class.java))
                })
            }
        }
    }
}

@Composable
fun ExampleComposable(data: DataExample, onButtonClick: () -> Unit) {
    Button(onClick = onButtonClick) {
        Text(data.title)
    }
}
```

<br />

## Case study: Broadcast receivers

For a more realistic example of features you might want to migrate or implement
in Compose, and to showcase `CompositionLocal` and [side
effects](https://developer.android.com/develop/ui/compose/side-effects), let's say a
[`BroadcastReceiver`](https://developer.android.com/guide/components/broadcasts) needs to be registered from
a composable function.

The solution makes use of `LocalContext` to use the current context, and
`rememberUpdatedState` and `DisposableEffect` side effects.


```kotlin
@Composable
fun SystemBroadcastReceiver(
    systemAction: String,
    onSystemEvent: (intent: Intent?) -> Unit
) {
    // Grab the current context in this part of the UI tree
    val context = LocalContext.current

    // Safely use the latest onSystemEvent lambda passed to the function
    val currentOnSystemEvent by rememberUpdatedState(onSystemEvent)

    // If either context or systemAction changes, unregister and register again
    DisposableEffect(context, systemAction) {
        val intentFilter = IntentFilter(systemAction)
        val broadcast = object : BroadcastReceiver() {
            override fun onReceive(context: Context?, intent: Intent?) {
                currentOnSystemEvent(intent)
            }
        }

        context.registerReceiver(broadcast, intentFilter)

        // When the effect leaves the Composition, remove the callback
        onDispose {
            context.unregisterReceiver(broadcast)
        }
    }
}

@Composable
fun HomeScreen() {

    SystemBroadcastReceiver(Intent.ACTION_BATTERY_CHANGED) { batteryStatus ->
        val isCharging = /* Get from batteryStatus ... */ true
        /* Do something if the device is charging */
    }

    /* Rest of the HomeScreen */
}
```

<br />

## Next steps

Now that you know the interoperability APIs when using Compose in Views and vice
versa, explore the [Other considerations](https://developer.android.com/develop/ui/compose/migrate/other-considerations) page to learn more.

## Recommended for you

- Note: link text is displayed when JavaScript is off
- [Other considerations](https://developer.android.com/develop/ui/compose/migrate/other-considerations)
- [Side-effects in Compose](https://developer.android.com/develop/ui/compose/side-effects)
- [Locally scoped data with CompositionLocal](https://developer.android.com/develop/ui/compose/compositionlocal)