Package android.os

Class CancellationSignal

java.lang.Object

android.os.CancellationSignal

public final class CancellationSignal
extends Object

Provides the ability to cancel an operation in progress.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CancellationSignal.OnCancelListener	Listens for cancellation.

Constructor Summary

Constructors

Constructor	Description
CancellationSignal()	Creates a cancellation signal, initially not canceled.

Method Summary

Modifier and Type	Method	Description
void	cancel()	Cancels the operation and signals the cancellation listener.
static android.os.ICancellationSignal	createTransport()	Creates a transport that can be returned back to the caller of a Binder function and subsequently used to dispatch a cancellation signal.
static CancellationSignal	fromTransport(android.os.ICancellationSignal transport)	Given a locally created transport, returns its associated cancellation signal.
boolean	isCanceled()	Returns true if the operation has been canceled.
void	setOnCancelListener(CancellationSignal.OnCancelListener listener)	Sets the cancellation listener to be called when canceled.
void	setRemote(android.os.ICancellationSignal remote)	Sets the remote transport.
void	throwIfCanceled()	Throws OperationCanceledException if the operation has been canceled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CancellationSignal

public CancellationSignal()

Creates a cancellation signal, initially not canceled.

Method Detail

isCanceled

public boolean isCanceled()

Returns true if the operation has been canceled.

Returns:

True if the operation has been canceled.

throwIfCanceled

public void throwIfCanceled()

Throws OperationCanceledException if the operation has been canceled.

Throws:

OperationCanceledException - if the operation has been canceled.

cancel

public void cancel()

Cancels the operation and signals the cancellation listener. If the operation has not yet started, then it will be canceled as soon as it does.

setOnCancelListener

public void setOnCancelListener(CancellationSignal.OnCancelListener listener)

Sets the cancellation listener to be called when canceled. This method is intended to be used by the recipient of a cancellation signal such as a database or a content provider to handle cancellation requests while performing a long-running operation. This method is not intended to be used by applications themselves. If cancel() has already been called, then the provided listener is invoked immediately. This method is guaranteed that the listener will not be called after it has been removed.

Parameters:

listener - The cancellation listener, or null to remove the current listener.

setRemote

public void setRemote(android.os.ICancellationSignal remote)

Sets the remote transport. If cancel() has already been called, then the provided remote transport is canceled immediately. This method is guaranteed that the remote transport will not be called after it has been removed.

Parameters:

remote - The remote transport, or null to remove.

createTransport

public static android.os.ICancellationSignal createTransport()

Creates a transport that can be returned back to the caller of a Binder function and subsequently used to dispatch a cancellation signal.

Returns:

The new cancellation signal transport.

fromTransport

public static CancellationSignal fromTransport(android.os.ICancellationSignal transport)

Given a locally created transport, returns its associated cancellation signal.

Parameters:

transport - The locally created transport, or null if none.

Returns:

The associated cancellation signal, or null if none.