CancellationSignal

Kotlin |Java

class CancellationSignal

kotlin.Any
↳	androidx.core.os.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 classes
abstract	OnCancelListener Listens for cancellation.

Public constructors
<init>() Creates a cancellation signal, initially not canceled.

Public methods
Unit	cancel() Cancels the operation and signals the cancellation listener.
Any?	getCancellationSignalObject() Gets the framework android.os.CancellationSignal associated with this object.
Boolean	isCanceled() Returns true if the operation has been canceled.
Unit	setOnCancelListener(@Nullable listener: CancellationSignal.OnCancelListener?) Sets the cancellation listener to be called when canceled.
Unit	throwIfCanceled() Throws OperationCanceledException if the operation has been canceled.

Public constructors

<init>

CancellationSignal()

Creates a cancellation signal, initially not canceled.

Public methods

cancel

fun cancel(): Unit

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

@Nullable fun getCancellationSignalObject(): Any?

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

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

Return
Any?: A framework cancellation signal object, or null on platform versions prior to Jellybean.

isCanceled

fun isCanceled(): Boolean

Returns true if the operation has been canceled.

Return
Boolean: True if the operation has been canceled.

setOnCancelListener

fun setOnCancelListener(@Nullable listener: CancellationSignal.OnCancelListener?): Unit

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 CancellationSignal#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	CancellationSignal.OnCancelListener?: The cancellation listener, or null to remove the current listener.

throwIfCanceled

fun throwIfCanceled(): Unit

Throws OperationCanceledException if the operation has been canceled.

Exceptions
OperationCanceledException	if the operation has been canceled.