Added in API level 11
Deprecated in API level 28

AsyncTaskLoader


abstract class AsyncTaskLoader<D : Any!> : Loader<D>
kotlin.Any
   ↳ android.content.Loader<D>
   ↳ android.content.AsyncTaskLoader

Abstract Loader that provides an AsyncTask to do the work. See Loader and android.app.LoaderManager for more details.

Here is an example implementation of an AsyncTaskLoader subclass that loads the currently installed applications from the package manager. This implementation takes care of retrieving the application labels and sorting its result set from them, monitoring for changes to the installed applications, and rebuilding the list when a change in configuration requires this (such as a locale change).

An example implementation of a fragment that uses the above loader to show the currently installed applications in a list is below.

Summary

Public constructors

Public methods
open Unit

Called on the main thread to abort a load in progress.

open Unit
dump(prefix: String!, fd: FileDescriptor!, writer: PrintWriter!, args: Array<String!>!)

open Boolean

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

abstract D

Called on a worker thread to perform the actual load and to return the result of the load operation.

open Unit
onCanceled(data: D)

Called if the task was canceled before it was completed.

open Unit

Set amount to throttle updates by.

Protected methods
open Boolean

open Unit

open D

Calls loadInBackground().

Inherited functions

Public constructors

AsyncTaskLoader

Added in API level 11
AsyncTaskLoader(context: Context!)

Public methods

cancelLoadInBackground

Added in API level 16
Deprecated in API level 28
open fun cancelLoadInBackground(): Unit

Deprecated: Deprecated in Java.

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.

dump

Added in API level 11
open fun dump(
    prefix: String!,
    fd: FileDescriptor!,
    writer: PrintWriter!,
    args: Array<String!>!
): Unit

Deprecated: Deprecated in Java.

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 Array<String!>!: Additional arguments to the dump request.

isLoadInBackgroundCanceled

Added in API level 16
Deprecated in API level 28
open fun isLoadInBackgroundCanceled(): Boolean

Deprecated: Deprecated in Java.

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

Return
Boolean True if the current invocation of loadInBackground is being canceled.

loadInBackground

Added in API level 11
abstract fun loadInBackground(): D

Deprecated: Deprecated in Java.

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 on the UI thread. If implementations need to process the results on the UI thread they may override deliverResult 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 to perform post-cancellation cleanup and to dispose of the result object, if any.

Return
D The result of the load operation.
Exceptions
android.os.OperationCanceledException if the load is canceled during execution.

onCanceled

Added in API level 11
open fun onCanceled(data: D): Unit

Deprecated: Deprecated in Java.

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 API level 11
open fun setUpdateThrottle(delayMS: Long): Unit

Deprecated: Deprecated in Java.

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 API level 16
Deprecated in API level 28
protected open fun onCancelLoad(): Boolean

Deprecated: Deprecated in Java.

Return
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 OnLoadCanceledListener will be called when the task completes.

onForceLoad

Added in API level 11
protected open fun onForceLoad(): Unit

Deprecated: Deprecated in Java.

onLoadInBackground

Added in API level 11
protected open fun onLoadInBackground(): D

Deprecated: Deprecated in Java.

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

Return
D The result of the load operation.
Exceptions
android.os.OperationCanceledException if the load is canceled during execution.