# FragmentManager.OnBackStackChangedListener

Added in[API level 11](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  
Deprecated in[API level 28](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)

# OnBackStackChangedListener

*** ** * ** ***

Kotlin\|[Java](https://developer.android.com/reference/android/app/FragmentManager.OnBackStackChangedListener "View this page in Java")  

```
interface OnBackStackChangedListener
```

|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [android.app.FragmentManager.OnBackStackChangedListener](https://developer.android.com/reference/kotlin/android/app/FragmentManager.OnBackStackChangedListener#) |

|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Known Direct Subclasses [FragmentBreadCrumbs](https://developer.android.com/reference/kotlin/android/app/FragmentBreadCrumbs) |-------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------| | [FragmentBreadCrumbs](https://developer.android.com/reference/kotlin/android/app/FragmentBreadCrumbs) | Helper class for showing "bread crumbs" representing the fragment stack in an activity. | |

*** ** * ** ***

| **This interface was deprecated in API level 28.**
|
| Use the[Support Library](https://developer.android.com/tools/extras/support-library.html)androidx.fragment.app.FragmentManager.OnBackStackChangedListener

Interface to watch for changes to the back stack.

## Summary

|                                                                                                                                          Public methods                                                                                                                                           ||
|--------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [onBackStackChanged](https://developer.android.com/reference/kotlin/android/app/FragmentManager.OnBackStackChangedListener#onBackStackChanged())`()` Called whenever the contents of the back stack change. |

## Public methods

### onBackStackChanged

Added in[API level 11](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)  

```
abstract fun onBackStackChanged(): Unit
```

**Deprecated:** *Deprecated in Java.*

Called whenever the contents of the back stack change.