added in version 22.1.0
belongs to Maven artifact com.android.support:loader:28.0.0-alpha1

Summary: Nested Classes | Ctors | Methods | Inherited Methods | [Expand All]

LoaderManager

This package is part of the Android support library which is no longer maintained. The support library has been superseded by AndroidX which is part of Jetpack. We recommend using the AndroidX libraries in all new projects. You should also consider migrating existing projects to AndroidX. To find the AndroidX class that maps to this deprecated class, see the AndroidX support library class mappings.

public abstract class LoaderManager
extends Object

java.lang.Object
↳	android.support.v4.app.LoaderManager

---

Static library support version of the framework's LoaderManager. Used to write apps that run on platforms prior to Android 3.0. When running on Android 3.0 or above, this implementation is still used; it does not try to switch to the framework's implementation. See the framework SDK documentation for a class overview.

Your activity must derive from FragmentActivity to use this.

Summary

Nested classes
interface	LoaderManager.LoaderCallbacks<D> Callback interface for a client to interact with the manager.

Public constructors
LoaderManager()

Public methods
abstract void	destroyLoader(int id) Stops and removes the loader with the given ID.
abstract void	dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the LoaderManager's state into the given stream.
static void	enableDebugLogging(boolean enabled) Control whether the framework's internal loader manager debugging logs are turned on.
static <T extends LifecycleOwner & ViewModelStoreOwner> LoaderManager	getInstance(T owner) Gets a LoaderManager associated with the given owner, such as a FragmentActivity or Fragment.
abstract <D> Loader<D>	getLoader(int id) Return the Loader with the given id or null if no matching Loader is found.
boolean	hasRunningLoaders() Returns true if any loaders managed are currently running and have not returned data to the application yet.
abstract <D> Loader<D>	initLoader(int id, Bundle args, LoaderCallbacks<D> callback) Ensures a loader is initialized and active.
abstract void	markForRedelivery() Mark all Loaders associated with this LoaderManager for redelivery of their current data (if any), waiting for the next time the Loader is started if it is currently stopped.
abstract <D> Loader<D>	restartLoader(int id, Bundle args, LoaderCallbacks<D> callback) Starts a new or restarts an existing Loader in this manager, registers the callbacks to it, and (if the activity/fragment is currently started) starts loading it.

Inherited methods
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait(long arg0, int arg1) final void wait(long arg0) final void wait()

Public constructors

LoaderManager

added in version 22.1.0

LoaderManager ()

Public methods

destroyLoader

added in version 22.1.0

void destroyLoader (int id)

Stops and removes the loader with the given ID. If this loader had previously reported data to the client through onLoadFinished(Loader, Object), a call will be made to onLoaderReset(Loader).

Must be called from the process's main thread.

Parameters
id	int

dump

added in version 22.1.0

void dump (String prefix, 
                FileDescriptor fd, 
                PrintWriter writer, 
                String[] args)

Print the LoaderManager's state into the given stream.

Parameters
prefix	String: Text to print at the front of each line.
fd	FileDescriptor: The raw file descriptor that the dump is being sent to.
writer	PrintWriter: A PrintWriter to which the dump is to be set.
args	String: Additional arguments to the dump request.

enableDebugLogging

added in version 22.1.0

void enableDebugLogging (boolean enabled)

Control whether the framework's internal loader manager debugging logs are turned on. If enabled, you will see output in logcat as the framework performs loader operations.

Parameters
enabled	boolean

getInstance

LoaderManager getInstance (T owner)

Gets a LoaderManager associated with the given owner, such as a FragmentActivity or Fragment.

Parameters
owner	T: The owner that should be used to create the returned LoaderManager

Returns
LoaderManager	A valid LoaderManager

getLoader

added in version 22.1.0

Loader<D> getLoader (int id)

Return the Loader with the given id or null if no matching Loader is found.

Parameters
id	int

Returns
Loader<D>

hasRunningLoaders

added in version 22.1.0

boolean hasRunningLoaders ()

Returns true if any loaders managed are currently running and have not returned data to the application yet.

Returns
boolean

initLoader

added in version 22.1.0

Loader<D> initLoader (int id, 
                Bundle args, 
                LoaderCallbacks<D> callback)

Ensures a loader is initialized and active. If the loader doesn't already exist, one is created and (if the activity/fragment is currently started) starts the loader. Otherwise the last created loader is re-used.

In either case, the given callback is associated with the loader, and will be called as the loader state changes. If at the point of call the caller is in its started state, and the requested loader already exists and has generated its data, then callback onLoadFinished(Loader, D) will be called immediately (inside of this function), so you must be prepared for this to happen.

Must be called from the process's main thread.

Parameters
id	int: A unique identifier for this loader. Can be whatever you want. Identifiers are scoped to a particular LoaderManager instance.
args	Bundle: Optional arguments to supply to the loader at construction. If a loader already exists (a new one does not need to be created), this parameter will be ignored and the last arguments continue to be used.
callback	LoaderCallbacks: Interface the LoaderManager will call to report about changes in the state of the loader. Required.

Returns
Loader<D>

markForRedelivery

void markForRedelivery ()

Mark all Loaders associated with this LoaderManager for redelivery of their current data (if any), waiting for the next time the Loader is started if it is currently stopped. In cases where no data has yet been delivered, this is effectively a no-op. In cases where data has already been delivered via onLoadFinished(Loader, Object), this will ensure that onLoadFinished(Loader, Object) is called again with the same data.

Call this only if you are implementing a LifecycleOwner where the views/elements that developers are likely to use in onLoadFinished(Loader, Object) can be created and destroyed multiple times without the LifecycleOwner itself being destroyed. Call this when the views/elements are being destroyed to ensure that the data is redelivered upon recreation.

restartLoader

added in version 22.1.0

Loader<D> restartLoader (int id, 
                Bundle args, 
                LoaderCallbacks<D> callback)

Starts a new or restarts an existing Loader in this manager, registers the callbacks to it, and (if the activity/fragment is currently started) starts loading it. If a loader with the same id has previously been started it will automatically be destroyed when the new loader completes its work. The callback will be delivered before the old loader is destroyed.

Must be called from the process's main thread.

Parameters
id	int: A unique identifier for this loader. Can be whatever you want. Identifiers are scoped to a particular LoaderManager instance.
args	Bundle: Optional arguments to supply to the loader at construction.
callback	LoaderCallbacks: Interface the LoaderManager will call to report about changes in the state of the loader. Required.

Returns
Loader<D>

• Annotations

  • NotificationCompat.Action.SemanticAction

• Interfaces

  • ActionBarDrawerToggle.Delegate
  • ActionBarDrawerToggle.DelegateProvider
  • ActivityCompat.OnRequestPermissionsResultCallback
  • ActivityCompat.PermissionCompatDelegate
  • FragmentManager.BackStackEntry
  • FragmentManager.OnBackStackChangedListener
  • LoaderManager.LoaderCallbacks
  • NotificationCompat.Action.Extender
  • NotificationCompat.Extender
  • SharedElementCallback.OnSharedElementsReadyListener
  • TaskStackBuilder.SupportParentable

• Classes

  • ActionBarDrawerToggle
  • ActivityCompat
  • ActivityManagerCompat
  • ActivityOptionsCompat
  • AlarmManagerCompat
  • AppLaunchChecker
  • AppOpsManagerCompat
  • BundleCompat
  • DialogFragment
  • Fragment
  • Fragment.SavedState
  • FragmentActivity
  • FragmentContainer
  • FragmentController
  • FragmentHostCallback
  • FragmentManager
  • FragmentManager.FragmentLifecycleCallbacks
  • FragmentManagerNonConfig
  • FragmentPagerAdapter
  • FragmentStatePagerAdapter
  • FragmentTabHost
  • FragmentTransaction
  • FrameMetricsAggregator
  • JobIntentService
  • ListFragment
  • LoaderManager
  • NavUtils
  • NotificationCompat
  • NotificationCompat.Action
  • NotificationCompat.Action.Builder
  • NotificationCompat.Action.WearableExtender
  • NotificationCompat.BigPictureStyle
  • NotificationCompat.BigTextStyle
  • NotificationCompat.Builder
  • NotificationCompat.CarExtender
  • NotificationCompat.CarExtender.UnreadConversation
  • NotificationCompat.CarExtender.UnreadConversation.Builder
  • NotificationCompat.DecoratedCustomViewStyle
  • NotificationCompat.InboxStyle
  • NotificationCompat.MessagingStyle
  • NotificationCompat.MessagingStyle.Message
  • NotificationCompat.Style
  • NotificationCompat.WearableExtender
  • NotificationCompatExtras
  • NotificationCompatSideChannelService
  • NotificationManagerCompat
  • RemoteInput
  • RemoteInput.Builder
  • ServiceCompat
  • ShareCompat
  • ShareCompat.IntentBuilder
  • ShareCompat.IntentReader
  • SharedElementCallback
  • TaskStackBuilder

• Exceptions

  • Fragment.InstantiationException