com.chemaxon.calculations.common

Class CancelObserverImpl

java.lang.Object

com.chemaxon.calculations.common.CancelObserverImpl

All Implemented Interfaces:

CancelObserver

@Beta
public class CancelObserverImpl
extends Object
implements CancelObserver

Implementation of CancelObserver.

Please note that this interface is marked with @Beta annotation, so it can be subject of incompatible changes or removal in any of the later releases.

Constructor Summary

Constructors

Constructor and Description
CancelObserverImpl() Constructor for a cancellable observer implementation.
CancelObserverImpl(CancelObserver sourceCanceller) Constructor with an underlying polling source.

Method Summary

Modifier and Type	Method and Description
void	cancel() Sign cancelling.
boolean	isCancelled() Returns whether cancellation of current operation has been requested.

Methods inherited from class java.lang.Object

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

Constructor Detail

CancelObserverImpl

public CancelObserverImpl()

Constructor for a cancellable observer implementation.

CancelObserverImpl

public CancelObserverImpl(CancelObserver sourceCanceller)

Constructor with an underlying polling source.

Parameters:

sourceCanceller - canceller to poll

Method Detail

cancel

public void cancel()

Sign cancelling.

Note that this implementation is not thread safe, so this method must be invoked from the thread created/using this instance.

isCancelled

public boolean isCancelled()

Description copied from interface: CancelObserver

Returns whether cancellation of current operation has been requested.

Long running/memory intensive operations should poll to see if cancelation has been requested. Since time-out based cancelations might be implemented polling should not be done too often.

It is expected that implementations wont return false after a true value returned. It is also expected that implementations tolerate multiple calls regardless of the cancallation state.

Please note that test cases might check for too frequent invocations, so the propagation of any AssertionError thrown by this method should not be obstructed.

It is usually expected that the cancelled task should throw CancellationException and this behavior should be documented in their APIdocs.

Specified by:

isCancelled in interface CancelObserver

Returns:

true if cancellation has been requested, false otherwise.