belongs to Maven artifact com.android.support:loader:28.0.0-alpha1
AsyncTaskLoader
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
|
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 |
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 |
void
|
onForceLoad()
Subclasses must implement this to take care of requests to |
D
|
onLoadInBackground()
Calls |
Inherited methods | |
|---|---|
From
class
android.support.v4.content.Loader
| |
From
class
java.lang.Object
| |
Public constructors
AsyncTaskLoader
AsyncTaskLoader (Context context)
| Parameters | |
|---|---|
context |
Context |
Public methods
cancelLoadInBackground
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:
dump
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
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
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. |
onCanceled
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
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
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
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
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:
Interfaces
Classes