Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Constants](https://developer.android.com/reference/android/content/ComponentCallbacks2#constants) \| [Methods](https://developer.android.com/reference/android/content/ComponentCallbacks2#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/android/content/ComponentCallbacks2#inhmethods)

# ComponentCallbacks2

*** ** * ** ***


`
public


interface
ComponentCallbacks2
`


`


implements

https://developer.android.com/reference/android/content/ComponentCallbacks


`

|---|
| android.content.ComponentCallbacks2 |

Known indirect subclasses [AbstractInputMethodService](https://developer.android.com/reference/android/inputmethodservice/AbstractInputMethodService), [AccessibilityService](https://developer.android.com/reference/android/accessibilityservice/AccessibilityService), [AccountAuthenticatorActivity](https://developer.android.com/reference/android/accounts/AccountAuthenticatorActivity), [Activity](https://developer.android.com/reference/android/app/Activity), [ActivityGroup](https://developer.android.com/reference/android/app/ActivityGroup), [AliasActivity](https://developer.android.com/reference/android/app/AliasActivity), [AlternativeMessageTransportService](https://developer.android.com/reference/android/service/messaging/AlternativeMessageTransportService), [AppContentProjectionService](https://developer.android.com/reference/android/media/projection/AppContentProjectionService), [AppFunctionService](https://developer.android.com/reference/android/app/appfunctions/AppFunctionService), [Application](https://developer.android.com/reference/android/app/Application), [AutofillService](https://developer.android.com/reference/android/service/autofill/AutofillService), [CallRedirectionService](https://developer.android.com/reference/android/telecom/CallRedirectionService), [CallScreeningService](https://developer.android.com/reference/android/telecom/CallScreeningService), [CameraPrewarmService](https://developer.android.com/reference/android/service/media/CameraPrewarmService), [CarrierMessagingClientService](https://developer.android.com/reference/android/service/carrier/CarrierMessagingClientService), and 66 others. [AbstractInputMethodService](https://developer.android.com/reference/android/inputmethodservice/AbstractInputMethodService) AbstractInputMethodService provides a abstract base class for input methods. [AccessibilityService](https://developer.android.com/reference/android/accessibilityservice/AccessibilityService) Accessibility services should only be used to assist users with disabilities in using Android devices and apps. [AccountAuthenticatorActivity](https://developer.android.com/reference/android/accounts/AccountAuthenticatorActivity) *This class was deprecated
in API level 30.
Applications should extend Activity themselves. This class is not compatible with
AppCompat, and the functionality it provides is not complex.* [Activity](https://developer.android.com/reference/android/app/Activity) An activity is a single, focused thing that the user can do. [ActivityGroup](https://developer.android.com/reference/android/app/ActivityGroup) *This class was deprecated
in API level 13.
Use the new `https://developer.android.com/reference/android/app/Fragment` and `https://developer.android.com/reference/android/app/FragmentManager` APIs
instead; these are also
available on older platforms through the Android compatibility package.* [AliasActivity](https://developer.android.com/reference/android/app/AliasActivity) *This class was deprecated
in API level 30.
Use `<activity-alias>` or subclass Activity directly.* [AlternativeMessageTransportService](https://developer.android.com/reference/android/service/messaging/AlternativeMessageTransportService) AlternativeMessageTransportService (AMTS) allows the default SMS app to handle the sending of a message over a different transport (e.g. RCS etc.) other than the SMS or MMS. [AppContentProjectionService](https://developer.android.com/reference/android/media/projection/AppContentProjectionService) Service to be implemented by the application providing the `https://developer.android.com/reference/android/media/projection/MediaProjectionAppContent`. [AppFunctionService](https://developer.android.com/reference/android/app/appfunctions/AppFunctionService) Extend this class to implement app functions, that can be executed by `https://developer.android.com/reference/android/app/appfunctions/AppFunctionManager#executeAppFunction(android.app.AppInteractionSession,%20android.app.appfunctions.ExecuteAppFunctionRequest,%20java.util.concurrent.Executor,%20android.os.CancellationSignal,%20android.os.OutcomeReceiver<android.app.appfunctions.ExecuteAppFunctionResponse,android.app.appfunctions.AppFunctionException>)`. [Application](https://developer.android.com/reference/android/app/Application) Base class for maintaining global application state. [AutofillService](https://developer.android.com/reference/android/service/autofill/AutofillService) An `AutofillService` is a service used to automatically fill the contents of the screen on behalf of a given user - for more information about autofill, read [Autofill Framework](https://developer.android.com/preview/features/autofill). [CallRedirectionService](https://developer.android.com/reference/android/telecom/CallRedirectionService) This service can be implemented to interact between Telecom and its implementor for making outgoing call with optional redirection/cancellation purposes. [CallScreeningService](https://developer.android.com/reference/android/telecom/CallScreeningService) This service can be implemented by the default dialer (see `https://developer.android.com/reference/android/telecom/TelecomManager#getDefaultDialerPackage()`) or a third party app to allow or disallow incoming calls before they are shown to a user. [CameraPrewarmService](https://developer.android.com/reference/android/service/media/CameraPrewarmService) Extend this class to implement a camera prewarm service. [CarrierMessagingClientService](https://developer.android.com/reference/android/service/carrier/CarrierMessagingClientService) If the default SMS app has a service that extends this class, the system always tries to bind it so that the process is always running, which allows the app to have a persistent connection to the server. [CarrierMessagingService](https://developer.android.com/reference/android/service/carrier/CarrierMessagingService) A service that receives calls from the system when new SMS and MMS are sent or received. [CarrierService](https://developer.android.com/reference/android/service/carrier/CarrierService) A service that exposes carrier-specific functionality to the system. [ChooserTargetService](https://developer.android.com/reference/android/service/chooser/ChooserTargetService) *This class was deprecated
in API level 30.
For publishing direct share targets, please follow the instructions in
https://developer.android.com/training/sharing/receive.html#providing-direct-share-targets
instead.* [CloudMediaProvider](https://developer.android.com/reference/android/provider/CloudMediaProvider) Base class for a cloud media provider. [CompanionDeviceService](https://developer.android.com/reference/android/companion/CompanionDeviceService) A service that receives calls from the system with device events. [ConditionProviderService](https://developer.android.com/reference/android/service/notification/ConditionProviderService) *This class was deprecated
in API level 29.
Instead of using an automatically bound service, use
`https://developer.android.com/reference/android/app/NotificationManager#setAutomaticZenRuleState(java.lang.String,%20android.service.notification.Condition)` to tell the
system about the state of your rule. In order to maintain a link from
Settings to your rule configuration screens, provide a configuration activity that handles
`https://developer.android.com/reference/android/app/NotificationManager#ACTION_AUTOMATIC_ZEN_RULE` on your
`https://developer.android.com/reference/android/app/AutomaticZenRule` via
`https://developer.android.com/reference/android/app/AutomaticZenRule#setConfigurationActivity(android.content.ComponentName)`.* [ConnectionService](https://developer.android.com/reference/android/telecom/ConnectionService) An abstract service that should be implemented by any apps which either:

1. Can make phone calls (VoIP or otherwise) and want those calls to be integrated into the built-in phone app.
[ContentProvider](https://developer.android.com/reference/android/content/ContentProvider) Content providers are one of the primary building blocks of Android applications, providing content to applications. [ContentSafetyAppService](https://developer.android.com/reference/android/service/contentsafety/ContentSafetyAppService) Base class for a service that the `android.app.role.RoleManager.ROLE_CONTENT_SAFETY` role holder must implement. [ControlsProviderService](https://developer.android.com/reference/android/service/controls/ControlsProviderService) Service implementation allowing applications to contribute controls to the System UI. [CredentialProviderService](https://developer.android.com/reference/android/service/credentials/CredentialProviderService) Service to be extended by credential providers, in order to return user credentials to the framework. [DataMigrationToPccService](https://developer.android.com/reference/android/app/privatecompute/DataMigrationToPccService) Base class for a service that handles data migration to the Private Compute Core (PCC) storage of an application. [DeviceAdminService](https://developer.android.com/reference/android/app/admin/DeviceAdminService) Base class for a service that device owner/profile owners can optionally have. [DialogFragment](https://developer.android.com/reference/android/app/DialogFragment) *This class was deprecated
in API level 28.
Use the [Support Library](https://developer.android.com/tools/extras/support-library)
`https://developer.android.com/reference/androidx/fragment/app/DialogFragment.html` for consistent behavior across all devices
and access to [Lifecycle](https://developer.android.com/topic/libraries/architecture/lifecycle).* [DocumentsProvider](https://developer.android.com/reference/android/provider/DocumentsProvider) Base class for a document provider. [DreamService](https://developer.android.com/reference/android/service/dreams/DreamService) Extend this class to implement a custom dream (available to the user as a "Daydream"). [EgressReceiverService](https://developer.android.com/reference/android/app/privatecompute/EgressReceiverService) Base Service to be implemented by the partner agent proxy process to receive egress queries from a client running inside the Private Compute Core (PCC) sandbox. [ExpandableListActivity](https://developer.android.com/reference/android/app/ExpandableListActivity) *This class was deprecated
in API level 30.
Use `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.html` or use
`https://developer.android.com/reference/android/widget/ExpandableListView` directly* [Fragment](https://developer.android.com/reference/android/app/Fragment) *This class was deprecated
in API level 28.
Use the [Jetpack Fragment Library](https://developer.android.com/jetpack)
`https://developer.android.com/reference/androidx/fragment/app/Fragment.html` for consistent behavior across all devices
and access to [Lifecycle](https://developer.android.com/topic/libraries/architecture/lifecycle).* [HostApduService](https://developer.android.com/reference/android/nfc/cardemulation/HostApduService) HostApduService is a convenience `https://developer.android.com/reference/android/app/Service` class that can be
extended to emulate an NFC card inside an Android
service component.


[HostNfcFService](https://developer.android.com/reference/android/nfc/cardemulation/HostNfcFService) HostNfcFService is a convenience `https://developer.android.com/reference/android/app/Service` class that can be
extended to emulate an NFC-F card inside an Android service component.


[InCallService](https://developer.android.com/reference/android/telecom/InCallService) This service is implemented by an app that wishes to provide functionality for managing phone calls. [InputMethodService](https://developer.android.com/reference/android/inputmethodservice/InputMethodService) InputMethodService provides a standard implementation of an InputMethod, which final implementations can derive from and customize. [IntentService](https://developer.android.com/reference/android/app/IntentService) *This class was deprecated
in API level 30.
IntentService is subject to all the
[background execution limits](https://developer.android.com/about/versions/oreo/background)
imposed with Android 8.0 (API level 26). Consider using `https://developer.android.com/reference/androidx/work/WorkManager.html`
instead.* [IsolatedService](https://developer.android.com/reference/android/adservices/ondevicepersonalization/IsolatedService) *This class was deprecated
in API level 37.
The ODP APIs are deprecated and will not be supported in future Android releases.
There is no direct replacement API available. Developers currently integrated with these APIs
must cease further integration efforts. For comprehensive details regarding this deprecation and
the future roadmap of Privacy Sandbox on Android, please consult the official Privacy Sandbox
developer documentation and announcements:
<https://privacysandbox.google.com>* [JobService](https://developer.android.com/reference/android/app/job/JobService) Entry point for the callback from the `https://developer.android.com/reference/android/app/job/JobScheduler`.


[LauncherActivity](https://developer.android.com/reference/android/app/LauncherActivity) *This class was deprecated
in API level 30.
Applications can implement this UI themselves using
`https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.html` and
`https://developer.android.com/reference/android/content/pm/PackageManager#queryIntentActivities(android.content.Intent,%20int)`* [ListActivity](https://developer.android.com/reference/android/app/ListActivity) *This class was deprecated
in API level 30.
Use `https://developer.android.com/reference/androidx/fragment/app/ListFragment.html` or
`https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.html` to implement your Activity instead.* [ListFragment](https://developer.android.com/reference/android/app/ListFragment) *This class was deprecated
in API level 28.
Use the [Support Library](https://developer.android.com/tools/extras/support-library)
`https://developer.android.com/reference/androidx/fragment/app/ListFragment.html` for consistent behavior across all devices
and access to [Lifecycle](https://developer.android.com/topic/libraries/architecture/lifecycle).* [MediaBrowserService](https://developer.android.com/reference/android/service/media/MediaBrowserService) Base class for media browser services. [MediaRoute2ProviderService](https://developer.android.com/reference/android/media/MediaRoute2ProviderService) Base class for media route provider services. [MediaSession2Service](https://developer.android.com/reference/android/media/MediaSession2Service) *This class was deprecated
in API level 37.
Use the Media3 support library's `androidx.media3.session.MediaSessionService`
instead.* [MidiDeviceService](https://developer.android.com/reference/android/media/midi/MidiDeviceService) A service that implements a virtual MIDI device. [MidiUmpDeviceService](https://developer.android.com/reference/android/media/midi/MidiUmpDeviceService) A service that implements a virtual MIDI device for Universal MIDI Packets (UMP). [MockApplication](https://developer.android.com/reference/android/test/mock/MockApplication) *This class was deprecated
in API level 24.
Use a mocking framework like [Mockito](https://github.com/mockito/mockito).
New tests should be written using the
[Android Testing Support Library](https://developer.android.com/tools/testing-support-library).* [MockContentProvider](https://developer.android.com/reference/android/test/mock/MockContentProvider) Mock implementation of ContentProvider. [NativeActivity](https://developer.android.com/reference/android/app/NativeActivity) Convenience for implementing an activity that will be implemented purely in native code. [NotificationListenerService](https://developer.android.com/reference/android/service/notification/NotificationListenerService) A service that receives calls from the system when new notifications are posted or removed, or their ranking changed. [OffHostApduService](https://developer.android.com/reference/android/nfc/cardemulation/OffHostApduService) OffHostApduService is a convenience `https://developer.android.com/reference/android/app/Service` class that can be
extended to describe one or more NFC applications that are residing
off-host, for example on an embedded secure element or a UICC.


[PccService](https://developer.android.com/reference/android/app/privatecompute/PccService) Abstract base class for a PCC service that receives data from other components. [PreferenceActivity](https://developer.android.com/reference/android/preference/PreferenceActivity) *This class was deprecated
in API level 29.
Use the [AndroidX](https://developer.android.com/jetpack/androidx)
[Preference Library](https://developer.android.com/reference/androidx/preference/package-summary) for consistent behavior across all devices. For more information on
using the AndroidX Preference Library see
[Settings](https://developer.android.com/guide/topics/ui/settings).* [PreferenceFragment](https://developer.android.com/reference/android/preference/PreferenceFragment) *This class was deprecated
in API level 28.
Use the [AndroidX](https://developer.android.com/jetpack/androidx)
[Preference Library](https://developer.android.com/reference/androidx/preference/package-summary) for consistent behavior across all devices. For more information on
using the AndroidX Preference Library see
[Settings](https://developer.android.com/guide/topics/ui/settings).* [PrintService](https://developer.android.com/reference/android/printservice/PrintService)
This is the base class for implementing print services.


[QuickAccessWalletService](https://developer.android.com/reference/android/service/quickaccesswallet/QuickAccessWalletService) A `QuickAccessWalletService` provides a list of `WalletCard`s shown in the Quick Access Wallet. [RecognitionService](https://developer.android.com/reference/android/speech/RecognitionService) This class provides a base class for recognition service implementations. [RemoteViewsService](https://developer.android.com/reference/android/widget/RemoteViewsService) The service to be connected to for a remote adapter to request RemoteViews. [SearchRecentSuggestionsProvider](https://developer.android.com/reference/android/content/SearchRecentSuggestionsProvider) This superclass can be used to create a simple search suggestions provider for your application. [Service](https://developer.android.com/reference/android/app/Service) A Service is an application component representing either an application's desire to perform a longer-running operation while not interacting with the user or to supply functionality for other applications to use. [SettingInjectorService](https://developer.android.com/reference/android/location/SettingInjectorService) Dynamically specifies the summary (subtitle) and enabled status of a preference injected into the list of app settings displayed by the system settings app

<br />

For use only by apps that are included in the system image, for preferences that affect multiple apps. [SettingsPreferenceService](https://developer.android.com/reference/android/service/settings/preferences/SettingsPreferenceService) Base class for a service that exposes its settings preferences to external access. [SliceProvider](https://developer.android.com/reference/android/app/slice/SliceProvider) *This class was deprecated
in API level 35.
Slice framework has been deprecated, it will not receive any updates from
`https://developer.android.com/` and forward. If you are looking for a
framework that sends displayable data from one app to another, consider using
`https://developer.android.com/reference/android/app/appsearch/AppSearchManager`.* [SpellCheckerService](https://developer.android.com/reference/android/service/textservice/SpellCheckerService) SpellCheckerService provides an abstract base class for a spell checker. [TabActivity](https://developer.android.com/reference/android/app/TabActivity) *This class was deprecated
in API level 13.
New applications should use Fragments instead of this class;
to continue to run on older devices, you can use the v4 support library
which provides a version of the Fragment API that is compatible down to
`https://developer.android.com/reference/android/os/Build.VERSION_CODES#DONUT`.* [TextToSpeechService](https://developer.android.com/reference/android/speech/tts/TextToSpeechService) Abstract base class for TTS engine implementations. [TileService](https://developer.android.com/reference/android/service/quicksettings/TileService) A TileService provides the user a tile that can be added to Quick Settings. [TvAdService](https://developer.android.com/reference/android/media/tv/ad/TvAdService) The TvAdService class represents a TV client-side advertisement service. [TvInputService](https://developer.android.com/reference/android/media/tv/TvInputService) The TvInputService class represents a TV input or source such as HDMI or built-in tuner which provides pass-through video or broadcast TV programs. [TvInteractiveAppService](https://developer.android.com/reference/android/media/tv/interactive/TvInteractiveAppService) A TV interactive application service is a service that provides runtime environment and runs TV interactive applications. [VisualVoicemailService](https://developer.android.com/reference/android/telephony/VisualVoicemailService) This service is implemented by dialer apps that wishes to handle OMTP or similar visual voicemails. [VoiceInteractionService](https://developer.android.com/reference/android/service/voice/VoiceInteractionService) Top-level service of the current global voice interactor, which is providing support for hotwording, the back-end of a `https://developer.android.com/reference/android/app/VoiceInteractor`, etc. [VoiceInteractionSession](https://developer.android.com/reference/android/service/voice/VoiceInteractionSession) An active voice interaction session, providing a facility for the implementation to interact with the user in the voice interaction layer. [VoiceInteractionSessionService](https://developer.android.com/reference/android/service/voice/VoiceInteractionSessionService) An active voice interaction session, initiated by a `https://developer.android.com/reference/android/service/voice/VoiceInteractionService`. [VpnService](https://developer.android.com/reference/android/net/VpnService) VpnService is a base class for applications to extend and build their own VPN solutions. [VrListenerService](https://developer.android.com/reference/android/service/vr/VrListenerService) A service that is bound from the system while running in virtual reality (VR) mode. [WallpaperService](https://developer.android.com/reference/android/service/wallpaper/WallpaperService) A wallpaper service is responsible for showing a live wallpaper behind applications that would like to sit on top of it. [WebViewFragment](https://developer.android.com/reference/android/webkit/WebViewFragment) *This class was deprecated
in API level 28.
Manually call `https://developer.android.com/reference/android/webkit/WebView#onPause()` and `https://developer.android.com/reference/android/webkit/WebView#onResume()`*   

*** ** * ** ***

Callbacks for app state transitions that can be used to improve background memory management.
This interface is available in all application components (`https://developer.android.com/reference/android/app/Activity`, `https://developer.android.com/reference/android/app/Service`, `https://developer.android.com/reference/android/content/ContentProvider`, and `https://developer.android.com/reference/android/app/Application`).

You should implement `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)` to release memory when your app goes to background
states. Doing so helps the system keep your app's process cached in memory for longer, such that
the next time that the user brings your app to the foreground, the app will perform a [warm or hot start](https://developer.android.com/topic/performance/vitals/launch-time), resuming faster and
retaining state.

## Trim memory levels and how to handle them

- `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN`   
  Your app's UI is no longer visible. This is a good time to release large memory allocations that are used only by your UI, such as `https://developer.android.com/reference/android/graphics/Bitmap`, or resources related to video playback or animations.
- `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_BACKGROUND`   
  Your app's process is considered to be in the background, and has become eligible to be killed in order to free memory for other processes. Releasing more memory will prolong the time that your process can remain cached in memory. An effective strategy is to release resources that can be re-built when the user returns to your app.

Apps that continue to do work for the user when they're not visible can respond to the `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN` callback by changing their behavior to favor lower memory usage. For
example, a music player may keep full-sized album art for all tracks in the currently playing
playlist as Bitmaps cached in memory. When the app is backgrounded but music playback continues,
the app can change the caching behavior to cache fewer, or smaller, Bitmaps in memory.

The ordinal values for trim levels represent an escalating series of memory pressure events,
with incrementing values accordingly. More states may be added in the future. As such, it's
important not to check for specific values, but rather check if the level passed to `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)` is greater than or equal to the levels that your application handles. For example:

    public void onTrimMemory(int level) {
        if (level >= TRIM_MEMORY_BACKGROUND) {
            // Release any resources that can be rebuilt
            // quickly when the app returns to the foreground
            releaseResources();
        } else if (level >= TRIM_MEMORY_UI_HIDDEN) {
            // Release UI-related resources
            releaseUiResources();
        }
    }

**Note:** the runtime may invoke Garbage Collection (GC) in response
to application state changes. There is no need to explicitly invoke GC from your app.

## Summary

| ### Constants ||
|---|---|
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_BACKGROUND` Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process has gone on to the LRU list. |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_COMPLETE` *This constant was deprecated in API level 35. Apps are not notified of this level since API level 34* |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_MODERATE` *This constant was deprecated in API level 35. Apps are not notified of this level since API level 34* |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_CRITICAL` *This constant was deprecated in API level 35. Apps are not notified of this level since API level 34* |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_LOW` *This constant was deprecated in API level 35. Apps are not notified of this level since API level 34* |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_MODERATE` *This constant was deprecated in API level 35. Apps are not notified of this level since API level 34* |
| `int` | `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN` Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process had been showing a user interface, and is no longer doing so. |

| ### Public methods ||
|---|---|
| ` abstract void` | ` https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)(int level) ` Called when the operating system has determined that it is a good time for a process to trim unneeded memory from its process. |

### Inherited methods

From interface `

https://developer.android.com/reference/android/content/ComponentCallbacks

` `
abstract


void` `
https://developer.android.com/reference/android/content/ComponentCallbacks#onConfigurationChanged(android.content.res.Configuration)(https://developer.android.com/reference/android/content/res/Configuration newConfig)
`

Called by the system when the device configuration changes while your
component is running.


`
abstract


void` `
https://developer.android.com/reference/android/content/ComponentCallbacks#onLowMemory()()
`

*This method was deprecated
in API level 35.
Since API level 14 this is superseded by
`https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`.
Since API level 34 this is never called.
If you're overriding ComponentCallbacks2#onTrimMemory and
your minSdkVersion is greater than API 14, you can provide
an empty implementation for this method.*


## Constants

### TRIM_MEMORY_BACKGROUND

Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_BACKGROUND
```

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process has gone on to the
LRU list. This is a good opportunity to clean up resources that can
efficiently and quickly be re-built if the user returns to the app.

<br />

Constant Value:

40
(0x00000028)


### TRIM_MEMORY_COMPLETE

Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)   
Deprecated in [API level
35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_COMPLETE
```


**This constant was deprecated
in API level 35.**   

Apps are not notified of this level since API level 34

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process is nearing the end
of the background LRU list, and if more memory isn't found soon it will
be killed.

<br />

Constant Value:

80
(0x00000050)


### TRIM_MEMORY_MODERATE

Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)   
Deprecated in [API level
35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_MODERATE
```


**This constant was deprecated
in API level 35.**   

Apps are not notified of this level since API level 34

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process is around the middle
of the background LRU list; freeing memory can help the system keep
other processes running later in the list for better overall performance.

<br />

Constant Value:

60
(0x0000003c)


### TRIM_MEMORY_RUNNING_CRITICAL

Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)   
Deprecated in [API level
35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_RUNNING_CRITICAL
```


**This constant was deprecated
in API level 35.**   

Apps are not notified of this level since API level 34

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process is not an expendable
background process, but the device is running extremely low on memory
and is about to not be able to keep any background processes running.
Your running process should free up as many non-critical resources as it
can to allow that memory to be used elsewhere. The next thing that
will happen after this is `https://developer.android.com/reference/android/content/ComponentCallbacks#onLowMemory()` called to report that
nothing at all can be kept in the background, a situation that can start
to notably impact the user.

<br />

Constant Value:

15
(0x0000000f)


### TRIM_MEMORY_RUNNING_LOW

Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)   
Deprecated in [API level
35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_RUNNING_LOW
```


**This constant was deprecated
in API level 35.**   

Apps are not notified of this level since API level 34

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process is not an expendable
background process, but the device is running low on memory.
Your running process should free up unneeded resources to allow that
memory to be used elsewhere.

<br />

Constant Value:

10
(0x0000000a)


### TRIM_MEMORY_RUNNING_MODERATE

Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)   
Deprecated in [API level
35](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_RUNNING_MODERATE
```


**This constant was deprecated
in API level 35.**   

Apps are not notified of this level since API level 34

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process is not an expendable
background process, but the device is running moderately low on memory.
Your running process may want to release some unneeded resources for
use elsewhere.

<br />

Constant Value:

5
(0x00000005)


### TRIM_MEMORY_UI_HIDDEN

Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public static final int TRIM_MEMORY_UI_HIDDEN
```

Level for `https://developer.android.com/reference/android/content/ComponentCallbacks2#onTrimMemory(int)`: the process had been showing
a user interface, and is no longer doing so. Large allocations with
the UI should be released at this point to allow memory to be better
managed.

<br />

Constant Value:

20
(0x00000014)


## Public methods

### onTrimMemory

Added in [API level 14](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public abstract void onTrimMemory (int level)
```

Called when the operating system has determined that it is a good
time for a process to trim unneeded memory from its process.

You should never compare to exact values of the level, since new
intermediate values may be added -- you will typically want to compare if
the value is greater or equal to a level you are interested in.

To retrieve the processes current trim level at any point, you can
use `https://developer.android.com/reference/android/app/ActivityManager#getMyMemoryState(android.app.ActivityManager.RunningAppProcessInfo)`.

<br />

| Parameters ||
|---|---|
| `level` | `int`: The context of the trim, giving a hint of the amount of trimming the application may like to perform. Value is one of the following: - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_COMPLETE` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_MODERATE` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_BACKGROUND` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_UI_HIDDEN` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_CRITICAL` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_LOW` - `https://developer.android.com/reference/android/content/ComponentCallbacks2#TRIM_MEMORY_RUNNING_MODERATE` |