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

Summary: Ctors | Methods | Protected Methods | Inherited Methods | [Expand All]

AsyncTaskLoader

This package is part of the Android support library which is no longer maintained. The support library has been superseded by AndroidX which is part of Jetpack.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 AsyncTaskLoader
extends Loader<D>

java.lang.Object
↳	android.support.v4.content.Loader<D>
	↳	android.support.v4.content.AsyncTaskLoader<D>

Known Direct Subclasses CursorLoader CursorLoader Static library support version of the framework's CursorLoader.

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Static library support version of the framework's AsyncTaskLoader. 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.

Summary

Public constructors
AsyncTaskLoader(Context context)

Public methods
void	cancelLoadInBackground() Called on the main thread to abort a load in progress.
void	dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Loader's state into the given stream.
boolean	isLoadInBackgroundCanceled() Returns true if the current invocation of loadInBackground() is being canceled.
abstract D	loadInBackground() Called on a worker thread to perform the actual load and to return the result of the load operation.
void	onCanceled(D data) Called if the task was canceled before it was completed.
void	setUpdateThrottle(long delayMS) Set amount to throttle updates by.

Protected methods
boolean	onCancelLoad() Subclasses must implement this to take care of requests to cancelLoad().
void	onForceLoad() Subclasses must implement this to take care of requests to forceLoad().
D	onLoadInBackground() Calls loadInBackground().

Inherited methods
From class android.support.v4.content.Loader void abandon() This function will normally be called for you automatically by LoaderManager when restarting a Loader. boolean cancelLoad() Attempt to cancel the current load task. void commitContentChanged() Commit that you have actually fully processed a content change that was returned by takeContentChanged(). String dataToString(D data) For debugging, converts an instance of the Loader's data class to a string that can be printed. void deliverCancellation() Informs the registered Loader.OnLoadCanceledListener that the load has been canceled. void deliverResult(D data) Sends the result of the load to the registered listener. void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) Print the Loader's state into the given stream. void forceLoad() Force an asynchronous load. Context getContext() int getId() boolean isAbandoned() Return whether this loader has been abandoned. boolean isReset() Return whether this load has been reset. boolean isStarted() Return whether this load has been started. void onAbandon() Subclasses implement this to take care of being abandoned. boolean onCancelLoad() Subclasses must implement this to take care of requests to cancelLoad(). void onContentChanged() Called when Loader.ForceLoadContentObserver detects a change. void onForceLoad() Subclasses must implement this to take care of requests to forceLoad(). void onReset() Subclasses must implement this to take care of resetting their loader, as per reset(). void onStartLoading() Subclasses must implement this to take care of loading their data, as per startLoading(). void onStopLoading() Subclasses must implement this to take care of stopping their loader, as per stopLoading(). void registerListener(int id, OnLoadCompleteListener<D> listener) Registers a class that will receive callbacks when a load is complete. void registerOnLoadCanceledListener(OnLoadCanceledListener<D> listener) Registers a listener that will receive callbacks when a load is canceled. void reset() This function will normally be called for you automatically by LoaderManager when destroying a Loader. void rollbackContentChanged() Report that you have abandoned the processing of a content change that was returned by takeContentChanged() and would like to rollback to the state where there is again a pending content change. final void startLoading() This function will normally be called for you automatically by LoaderManager when the associated fragment/activity is being started. void stopLoading() This function will normally be called for you automatically by LoaderManager when the associated fragment/activity is being stopped. boolean takeContentChanged() Take the current flag indicating whether the loader's content had changed while it was stopped. String toString() void unregisterListener(OnLoadCompleteListener<D> listener) Remove a listener that was previously added with registerListener(int, Loader.OnLoadCompleteListener). void unregisterOnLoadCanceledListener(OnLoadCanceledListener<D> listener) Unregisters a listener that was previously added with registerOnLoadCanceledListener(Loader.OnLoadCanceledListener).
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

AsyncTaskLoader

added in version 22.1.0

AsyncTaskLoader (Context context)

Parameters
context	Context

Public methods

cancelLoadInBackground

added in version 24.1.0

void cancelLoadInBackground ()

Called on the main thread to abort a load in progress. Override this method to abort the current invocation of loadInBackground() that is running in the background on a worker thread. This method should do nothing if loadInBackground() has not started running or if it has already finished.

See also:

• loadInBackground()

dump

added in version 22.1.0

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

Print the Loader'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.

isLoadInBackgroundCanceled

added in version 24.1.0

boolean isLoadInBackgroundCanceled ()

Returns true if the current invocation of loadInBackground() is being canceled.

Returns
boolean	True if the current invocation of loadInBackground() is being canceled.

See also:

• loadInBackground()

loadInBackground

added in version 22.1.0

D loadInBackground ()

Called on a worker thread to perform the actual load and to return the result of the load operation. Implementations should not deliver the result directly, but should return them from this method, which will eventually end up calling deliverResult(D) on the UI thread. If implementations need to process the results on the UI thread they may override deliverResult(D) and do so there. To support cancellation, this method should periodically check the value of isLoadInBackgroundCanceled() and terminate when it returns true. Subclasses may also override cancelLoadInBackground() to interrupt the load directly instead of polling isLoadInBackgroundCanceled(). When the load is canceled, this method may either return normally or throw OperationCanceledException. In either case, the Loader will call onCanceled(D) to perform post-cancellation cleanup and to dispose of the result object, if any.

Returns
D	The result of the load operation.

Throws
OperationCanceledException	if the load is canceled during execution.

See also:

• isLoadInBackgroundCanceled()
• cancelLoadInBackground()
• onCanceled(D)

onCanceled

added in version 22.1.0

void onCanceled (D data)

Called if the task was canceled before it was completed. Gives the class a chance to clean up post-cancellation and to properly dispose of the result.

Parameters
data	D: The value that was returned by loadInBackground(), or null if the task threw OperationCanceledException.

setUpdateThrottle

added in version 22.1.0

void setUpdateThrottle (long delayMS)

Set amount to throttle updates by. This is the minimum time from when the last loadInBackground() call has completed until a new load is scheduled.

Parameters
delayMS	long: Amount of delay, in milliseconds.

Protected methods

onCancelLoad

added in version 24.1.0

boolean onCancelLoad ()

Subclasses must implement this to take care of requests to cancelLoad(). This will always be called from the process's main thread.

Returns
boolean	Returns false if the task could not be canceled, typically because it has already completed normally, or because startLoading() hasn't been called; returns true otherwise. When true is returned, the task is still running and the Loader.OnLoadCanceledListener will be called when the task completes.

onForceLoad

added in version 22.1.0

void onForceLoad ()

Subclasses must implement this to take care of requests to forceLoad(). This will always be called from the process's main thread.

onLoadInBackground

added in version 22.1.0

D onLoadInBackground ()

Calls loadInBackground(). This method is reserved for use by the loader framework. Subclasses should override loadInBackground() instead of this method.

Returns
D	The result of the load operation.

Throws
OperationCanceledException	if the load is canceled during execution.

See also:

• loadInBackground()

• Interfaces

  • Loader.OnLoadCanceledListener
  • Loader.OnLoadCompleteListener

• Classes

  • AsyncTaskLoader
  • ContentResolverCompat
  • ContextCompat
  • CursorLoader
  • FileProvider
  • IntentCompat
  • Loader
  • Loader.ForceLoadContentObserver
  • LocalBroadcastManager
  • MimeTypeFilter
  • PermissionChecker
  • SharedPreferencesCompat
  • SharedPreferencesCompat.EditorCompat
  • WakefulBroadcastReceiver