# CastPlayer.TransferCallback

Artifact: [androidx.media3:media3-cast](https://developer.android.com/jetpack/androidx/releases/media3) [View Source](https://cs.android.com/search?q=file:androidx/media3/cast/CastPlayer.java+class:androidx.media3.cast.CastPlayer.TransferCallback)

*** ** * ** ***


```
interface CastPlayer.TransferCallback
```

<br />

Known direct subclasses [DefaultCastPlayerTransferCallback](https://developer.android.com/reference/kotlin/androidx/media3/cast/DefaultCastPlayerTransferCallback)

|---|---|
| `https://developer.android.com/reference/kotlin/androidx/media3/cast/DefaultCastPlayerTransferCallback` | The default `https://developer.android.com/reference/kotlin/androidx/media3/cast/CastPlayer.TransferCallback` implementation. |

*** ** * ** ***

Callback for moving state across players when transferring playback upon Cast session availability changes.

## Summary

| ### Constants |
|---|---|
| `const https://developer.android.com/reference/kotlin/androidx/media3/cast/CastPlayer.TransferCallback!` | `https://developer.android.com/reference/kotlin/androidx/media3/cast/CastPlayer.TransferCallback#DEFAULT()` |

| ### Public functions |
|---|---|
| `https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html` | `https://developer.android.com/reference/kotlin/androidx/media3/cast/CastPlayer.TransferCallback#transferState(androidx.media3.common.Player,androidx.media3.common.Player)(sourcePlayer: https://developer.android.com/reference/kotlin/androidx/media3/common/Player!, targetPlayer: https://developer.android.com/reference/kotlin/androidx/media3/common/Player!)` Called immediately before changing the active `https://developer.android.com/reference/kotlin/androidx/media3/common/Player`, with the intended use of transferring playback state. |

## Constants

### DEFAULT

```
const val DEFAULT: CastPlayer.TransferCallback!
```

## Public functions

### transferState

```
fun transferState(sourcePlayer: Player!, targetPlayer: Player!): Unit
```

Called immediately before changing the active `https://developer.android.com/reference/kotlin/androidx/media3/common/Player`, with the intended use of transferring playback state.

| Parameters |
|---|---|
| `sourcePlayer: https://developer.android.com/reference/kotlin/androidx/media3/common/Player!` | The `https://developer.android.com/reference/kotlin/androidx/media3/common/Player` from which playback is transferring, from which to fetch the state. |
| `targetPlayer: https://developer.android.com/reference/kotlin/androidx/media3/common/Player!` | The `https://developer.android.com/reference/kotlin/androidx/media3/common/Player` to which playback is transferring, to populate with state. |

| See also |
|---|---|
| `https://developer.android.com/reference/kotlin/androidx/media3/common/PlayerTransferState` |   |