org.freehep.record.loop.event
Interface RecordListener

All Superinterfaces:

EventListener

All Known Subinterfaces:

ChainableRecordListener

All Known Implementing Classes:

org.freehep.record.loop.event.ChainableRecordAdapter, RecordAdapter

public interface RecordListener

extends EventListener

This interface is, when added to a SequentialRecordLoop object, notified of any RecordEvent that occurs in that object. The attached diagram show the state machine that should be supported by any implementation of the SequentialRecordLoop or RecordListener interfaces. This machine is designed to support both batch and interactive execution.

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In a batch environment this class is configured, supplied with record, and finishes.

An interactive envrionment is more complex as the user can change the configuration of an instance of this class at any time that the SequentialRecordLoop object is not looping. This means that an instance of this class needs to check it is correctly configured at the start of any loop. For the first loop of an SequentialRecordLoop object its listener will receive a configure(org.freehep.record.loop.event.ConfigurationEvent) event to tell them to prepare to receive new records. After that loop the configuration may be changed before the next loop is executed. In that case the RecordListener will receive a reconfigure(org.freehep.record.loop.event.ConfigurationEvent) event indicating that the configuration has changes and that the listener should prepare itself for new records using this new configuration. If the configuration has not changed then the listener gets a simple resume(org.freehep.record.loop.event.RecordEvent) message to indicate that it is about to receive new records. The full state diagram for an EventListener is shown above

Once a loop has completed, or been interrupted, a suspend(org.freehep.record.loop.event.RecordEvent) event is sent by the SequentialRecordLoop object. this allows this class to release any time sensitive resources while the user considers their next move. Both a resume and a reconfigure event should be used to reacquire the resources that have been released.

This class' finish(org.freehep.record.loop.event.RecordEvent) method is invoked whenever it is removed from a SequentialRecordLoop object. This can be caused by a direct invocation of the loop's removeRecordListener or dispose method, which implicitly removes the loops listener if there is one. This event is also be triggered when a SequentialRecordLoop is reset. The finish event gives the RecordListener an opportunity to do any housekeeping task that are related to its participation in the SequentialRecordLoop such as output summary information. After handling a finish event this class should be prepared to handle a configure event as such an event will occur for the first loop after either the SequentialRecordLoop object has been reset or after this class has been added back to a SequentialRecordLoop.

Version:

$Id: RecordListener.java,v 1.1 2003/05/06 23:02:05 tonyj Exp $

Author:

patton

Source Code:

RecordListener.java

Method Summary

void	configure(ConfigurationEvent event) Tells this object to configure itself in preparation for the first recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) call.
void	finish(RecordEvent event) Tells this object that an SequentialRecordLoop to which is has been added has been disposed of, and this object should execute any housekeeping tasks trelated to its participation in this SequentialRecordLoop.
void	reconfigure(ConfigurationEvent event) Tells this object to reconfigure itself in preparation for a new set of recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls.
void	recordSupplied(RecordSuppliedEvent event) Called every time a new record is read by the SequentialRecordLoop's SequentialRecordSource object.
void	resume(RecordEvent event) Tells this object to prepare for a new set of recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls using the its existing configuration.
void	suspend(RecordEvent event) Tells this object that there will be either a resume(org.freehep.record.loop.event.RecordEvent) or reconfigure(org.freehep.record.loop.event.ConfigurationEvent) before any more recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls will be made.

Method Detail

configure

public void configure(ConfigurationEvent event)

Tells this object to configure itself in preparation for the first recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) call.

Parameters:

event - a ConfigurationEvent describing the configuration to use.

finish

public void finish(RecordEvent event)

Tells this object that an SequentialRecordLoop to which is has been added has been disposed of, and this object should execute any housekeeping tasks trelated to its participation in this SequentialRecordLoop.

Parameters:

event - the RecordEvent for this event.

recordSupplied

public void recordSupplied(RecordSuppliedEvent event)

Called every time a new record is read by the SequentialRecordLoop's SequentialRecordSource object.

Parameters:

event - a RecordSuppliedEvent describing the data supplied.

reconfigure

public void reconfigure(ConfigurationEvent event)

Tells this object to reconfigure itself in preparation for a new set of recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls.

Parameters:

event - a ConfigurationEvent describing the new configuration to use.

resume

public void resume(RecordEvent event)

Tells this object to prepare for a new set of recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls using the its existing configuration.

Parameters:

event - the RecordEvent for this event.

suspend

public void suspend(RecordEvent event)

Tells this object that there will be either a resume(org.freehep.record.loop.event.RecordEvent) or reconfigure(org.freehep.record.loop.event.ConfigurationEvent) before any more recordSupplied(org.freehep.record.loop.event.RecordSuppliedEvent) calls will be made.

Parameters:

event - the RecordEvent for this event.