ComponentCallbacks

android.content.ComponentCallbacks

Known Indirect Subclasses

AbstractInputMethodService, AccessibilityService, AccountAuthenticatorActivity, ActionBarActivity, Activity, ActivityGroup, AliasActivity, Application, ComponentCallbacks2, ContentProvider, DialogFragment, and 31 others.

AbstractInputMethodService	AbstractInputMethodService provides a abstract base class for input methods.
AccessibilityService	An accessibility service runs in the background and receives callbacks by the system when `AccessibilityEvent`s are fired.
AccountAuthenticatorActivity	Base class for implementing an Activity that is used to help implement an AbstractAccountAuthenticator.
ActionBarActivity	Base class for activities that use the support library action bar features.
Activity	An activity is a single, focused thing that the user can do.
ActivityGroup	This class was deprecated in API level 13. Use the new `Fragment` and `FragmentManager` APIs instead; these are also available on older platforms through the Android compatibility package.
AliasActivity	Stub activity that launches another activity (and then finishes itself) based on information in its component's manifest meta-data.
Application	Base class for those who need to maintain global application state.
ComponentCallbacks2	Extended `ComponentCallbacks` interface with a new callback for finer-grained memory management.
ContentProvider	Content providers are one of the primary building blocks of Android applications, providing content to applications.
DialogFragment	Static library support version of the framework's `DialogFragment`.
DocumentsProvider	Base class for a document provider.
DreamService	Extend this class to implement a custom dream (available to the user as a "Daydream").
ExpandableListActivity	An activity that displays an expandable list of items by binding to a data source implementing the ExpandableListAdapter, and exposes event handlers when the user selects an item.
FileProvider	FileProvider is a special subclass of `ContentProvider` that facilitates secure sharing of files associated with an app by creating a `content://` `Uri` for a file instead of a `file:///` `Uri`.
Fragment	Static library support version of the framework's `Fragment`.
FragmentActivity	Base class for activities that want to use the support-based `Fragment` and `Loader` APIs.
HostApduService	HostApduService is a convenience `Service` class that can be extended to emulate an NFC card inside an Android service component.
InputMethodService	InputMethodService provides a standard implementation of an InputMethod, which final implementations can derive from and customize.
IntentService	IntentService is a base class for `Service`s that handle asynchronous requests (expressed as `Intent`s) on demand.
LauncherActivity	Displays a list of all activities which can be performed for a given intent.
ListActivity	An activity that displays a list of items by binding to a data source such as an array or Cursor, and exposes event handlers when the user selects an item.
ListFragment	Static library support version of the framework's `ListFragment`.
MediaRouteChooserDialogFragment	Media route chooser dialog fragment.
MediaRouteControllerDialogFragment	Media route controller dialog fragment.
MediaRouteDiscoveryFragment	Media route discovery fragment.
MediaRouteProviderService	Base class for media route provider services.
MockApplication	A mock `Application` class.
MockContentProvider	Mock implementation of ContentProvider.
NativeActivity	Convenience for implementing an activity that will be implemented purely in native code.
NotificationListenerService	A service that receives calls from the system when new notifications are posted or removed.
OffHostApduService	OffHostApduService is a convenience `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.
PreferenceActivity	This is the base class for an activity to show a hierarchy of preferences to the user.
PreferenceFragment	Shows a hierarchy of `Preference` objects as lists.
PrintService	This is the base class for implementing print services.
RecognitionService	This class provides a base class for recognition service implementations.
RemoteViewsService	The service to be connected to for a remote adapter to request RemoteViews.
SearchRecentSuggestionsProvider	This superclass can be used to create a simple search suggestions provider for your application.
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	Dynamically specifies the summary (subtitle) and enabled status of a preference injected into the list of app settings displayed by the system settings app For use only by apps that are included in the system image, for preferences that affect multiple apps.
SpellCheckerService	SpellCheckerService provides an abstract base class for a spell checker.
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 `DONUT`.
TextToSpeechService	Abstract base class for TTS engine implementations.
VpnService	VpnService is a base class for applications to extend and build their own VPN solutions.
WallpaperService	A wallpaper service is responsible for showing a live wallpaper behind applications that would like to sit on top of it.
WebViewFragment	A fragment that displays a WebView.

Class Overview

The set of callback APIs that are common to all application components (Activity, Service, ContentProvider, and Application).

Note: You should also implement the ComponentCallbacks2 interface, which provides the onTrimMemory(int) callback to help your app manage its memory usage more effectively.

Summary

Public Methods
abstract void	onConfigurationChanged(Configuration newConfig) Called by the system when the device configuration changes while your component is running.
abstract void	onLowMemory() This is called when the overall system is running low on memory, and actively running processes should trim their memory usage.

Public Methods

public abstract void onConfigurationChanged (Configuration newConfig)

Added in API level 1

Called by the system when the device configuration changes while your component is running. Note that, unlike activities, other components are never restarted when a configuration changes: they must always deal with the results of the change, such as by re-retrieving resources.

At the time that this function has been called, your Resources object will have been updated to return resource values matching the new configuration.

For more information, read Handling Runtime Changes.

Parameters

newConfig	The new device configuration.

public abstract void onLowMemory ()

Added in API level 1

This is called when the overall system is running low on memory, and actively running processes should trim their memory usage. While the exact point at which this will be called is not defined, generally it will happen when all background process have been killed. That is, before reaching the point of killing processes hosting service and foreground UI that we would like to avoid killing.

You should implement this method to release any caches or other unnecessary resources you may be holding on to. The system will perform a garbage collection for you after returning from this method.

Preferably, you should implement onTrimMemory(int) from ComponentCallbacks2 to incrementally unload your resources based on various levels of memory demands. That API is available for API level 14 and higher, so you should only use this onLowMemory() method as a fallback for older versions, which can be treated the same as onTrimMemory(int) with the TRIM_MEMORY_COMPLETE level.

Results

Interfaces

Classes