CancellationSignal

public final class CancellationSignal


Static library support version of the framework's android.os.CancellationSignal. Used to write apps that run on platforms prior to Android 4.1. See the framework SDK documentation for a class overview.

Summary

Nested types

CancellationSignal.OnCancelListener

Listens for cancellation.

Public constructors

Creates a cancellation signal, initially not canceled.

Public methods

void

Cancels the operation and signals the cancellation listener.

@Nullable Object

Gets the framework android.os.CancellationSignal associated with this object.

boolean

Returns true if the operation has been canceled.

void

Sets the cancellation listener to be called when canceled.

void

Throws OperationCanceledException if the operation has been canceled.

Public constructors

CancellationSignal

public CancellationSignal()

Creates a cancellation signal, initially not canceled.

Public methods

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.

getCancellationSignalObject

public @Nullable Object getCancellationSignalObject()

Gets the framework android.os.CancellationSignal associated with this object.

Framework support for cancellation signals was added in JELLY_BEAN so this method will always return null on older versions of the platform.

Returns
@Nullable Object

A framework cancellation signal object, or null on platform versions prior to Jellybean.

isCanceled

public boolean isCanceled()

Returns true if the operation has been canceled.

Returns
boolean

True if the operation has been canceled.

setOnCancelListener

public void setOnCancelListener(
    @Nullable 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