Android APIs
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

Class Overview

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()
[Expand]
Inherited Methods
From class android.support.v4.content.Loader
From class java.lang.Object

Public Constructors

public AsyncTaskLoader (Context context)

Parameters
context

Public Methods

public 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:

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

Print the Loader's state into the given stream.

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

public 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:

public abstract 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.

public 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 The value that was returned by loadInBackground(), or null if the task threw OperationCanceledException.

public 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 Amount of delay, in milliseconds.

Protected Methods

protected 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.

protected void onForceLoad ()

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

protected 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: