# MediaRouteProvider.Callback

# MediaRouteProvider.Callback

Artifact:[androidx.mediarouter:mediarouter](https://developer.android.com/jetpack/androidx/releases/mediarouter)  
[View Source](https://cs.android.com/search?q=file:androidx/mediarouter/media/MediaRouteProvider.java+class:androidx.mediarouter.media.MediaRouteProvider.Callback)  
Added in[1.1.0](https://developer.android.com/jetpack/androidx/releases/mediarouter#1.1.0)

*** ** * ** ***

Kotlin\|[Java](https://developer.android.com/reference/androidx/mediarouter/media/MediaRouteProvider.Callback "View this page in Java")

<br />

```
abstract class MediaRouteProvider.Callback
```

<br />

*** ** * ** ***

Callback which is invoked when route information becomes available or changes.

## Summary

|                                                     ### Public constructors                                                      |
|----------------------------------------------------------------------------------------------------------------------------------|
| [Callback](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProvider.Callback#Callback())`()` |

|                             ### Public functions                              |
|-------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [Unit](https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-unit/index.html) | [onDescriptorChanged](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProvider.Callback#onDescriptorChanged(androidx.mediarouter.media.MediaRouteProvider,androidx.mediarouter.media.MediaRouteProviderDescriptor))`(` ` provider: `[MediaRouteProvider](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProvider)`,` ` descriptor: `[MediaRouteProviderDescriptor](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProviderDescriptor)`?` `)` Called when information about a route provider and its routes change. |

## Public constructors

### Callback

Added in 1.1.0  

```
Callback()
```  

## Public functions

### onDescriptorChanged

Added in[1.1.0](https://developer.android.com/jetpack/androidx/releases/mediarouter#1.1.0)  

```
fun onDescriptorChanged(
    provider: MediaRouteProvider,
    descriptor: MediaRouteProviderDescriptor?
): Unit
```

Called when information about a route provider and its routes change.  

|                                                                       Parameters                                                                        |
|---------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------|
| `provider: `[MediaRouteProvider](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProvider)                          | The media route provider that changed, never null.        |
| `descriptor: `[MediaRouteProviderDescriptor](https://developer.android.com/reference/kotlin/androidx/mediarouter/media/MediaRouteProviderDescriptor)`?` | The new media route provider descriptor, or null if none. |