edu.luc.cs.trull
Class Sequence

java.lang.Object
  edu.luc.cs.trull.EmptyComponent
      edu.luc.cs.trull.TerminatingComponent
          edu.luc.cs.trull.AbstractComponent
              edu.luc.cs.trull.AbstractCombinator
                  edu.luc.cs.trull.Sequence

All Implemented Interfaces:

Combinator, Component, PropertyChangeSource, Startable, Suspendable, Terminating, java.beans.PropertyChangeListener, java.util.EventListener

public class Sequence
extends AbstractCombinator

A combinator for executing zero or more components in sequence. The components that form part of the sequence should indicate termination. A sequence terminates when its last component terminates.

Nested Class Summary

protected class	Sequence.ForwardListener A dedicated listener that forwards the event to all external listeners.
protected class	Sequence.SequenceTerminationListener A termination listener that, when the current component terminates, starts the next component in the sequence.

Nested classes/interfaces inherited from class edu.luc.cs.trull.AbstractCombinator

AbstractCombinator.DefaultTerminationListener

Field Summary

private int	currentComponentIndex The index of the currently active component.
private Done	DONE An instance of Done used as the default child.
private java.beans.PropertyChangeListener	internalListener An internal listener that listens to the currently active child branch of this component and forwards events to the external listeners.
private static org.apache.log4j.Logger	logger
private TerminationListener	terminationListener The child termination listener of this component.

Fields inherited from class edu.luc.cs.trull.AbstractCombinator

components

Constructor Summary

Sequence()
Constructs a Sequence component.

Sequence(Component[] components)
Constructs a Sequence component consisting of the given list of components.

Sequence(Component first, Component second)
Constructs a Sequence component consisting of the two given components in order.

Method Summary

protected void	connectComponent(Component c) Hooks up the given component for communication and termination.
protected void	disconnectComponent(Component c) Unhooks the given component from communication and termination.
protected TerminationListener	getChildTerminationListener() Returns the internal listener that is notified if the child component terminates.
protected Component	getCurrentComponent() Returns the currently active component.
void	propertyChange(java.beans.PropertyChangeEvent evt) This method forwards events received from external sources to the components of this composite.
void	removeComponent(Component c) Removes the specified component from this combinator.
void	resume() Resumes this suspendable component.
void	start(java.beans.PropertyChangeEvent incoming) Starts this startable component.
void	stop() Stops this startable component.
void	suspend() Suspends this suspendable component.
protected void	switchToFirstComponent() Switches to the first component in the sequence.
protected void	switchToNextComponent() Switches to the next component in the sequence.

Methods inherited from class edu.luc.cs.trull.AbstractCombinator

addComponent, addComponent, addComponent, getComponent, getComponentCount, getComponents, removeAllComponents, removeComponent

Methods inherited from class edu.luc.cs.trull.AbstractComponent

addPropertyChangeListener, firePropertyChange, firePropertyChange, firePropertyChange, getExternalListeners, getPropertyChangeListeners, removePropertyChangeListener

Methods inherited from class edu.luc.cs.trull.TerminatingComponent

fireTermination, getParent, getTermEvent, scheduleTermination, setTerminationListener

Methods inherited from class edu.luc.cs.trull.EmptyComponent

getTerminationListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.luc.cs.trull.PropertyChangeSource

addPropertyChangeListener, getPropertyChangeListeners, removePropertyChangeListener

Methods inherited from interface edu.luc.cs.trull.Terminating

getTerminationListener, setTerminationListener

Field Detail

currentComponentIndex

private int currentComponentIndex

The index of the currently active component.

DONE

private final Done DONE

An instance of Done used as the default child.

internalListener

private java.beans.PropertyChangeListener internalListener

An internal listener that listens to the currently active child branch of this component and forwards events to the external listeners.

logger

private static final org.apache.log4j.Logger logger

terminationListener

private TerminationListener terminationListener

The child termination listener of this component.

Constructor Detail

Sequence

public Sequence()

Constructs a Sequence component. Specific properties can be changed later.

Sequence

public Sequence(Component[] components)

Constructs a Sequence component consisting of the given list of components.

Parameters:

components - the list of components in the sequence.

Sequence

public Sequence(Component first,
                Component second)

Constructs a Sequence component consisting of the two given components in order.

Parameters:

first - the first component in the sequence.

second - the second component in the sequence.

Method Detail

connectComponent

protected void connectComponent(Component c)

Hooks up the given component for communication and termination.

Parameters:

c - the component to be hooked up.

disconnectComponent

protected void disconnectComponent(Component c)

Unhooks the given component from communication and termination.

Parameters:

c - the component to be unhooked.

getChildTerminationListener

protected TerminationListener getChildTerminationListener()

Description copied from class: AbstractCombinator

Returns the internal listener that is notified if the child component terminates.

Specified by:

getChildTerminationListener in class AbstractCombinator

Returns:

the termination listener.

getCurrentComponent

protected Component getCurrentComponent()

Returns the currently active component.

Returns:

the currently active component.

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent evt)

This method forwards events received from external sources to the components of this composite.

Specified by:

propertyChange in interface java.beans.PropertyChangeListener

Overrides:

propertyChange in class EmptyComponent

Parameters:

evt - the event received.

removeComponent

public void removeComponent(Component c)

Description copied from class: AbstractCombinator

Removes the specified component from this combinator.

Specified by:

removeComponent in interface Combinator

Overrides:

removeComponent in class AbstractCombinator

Parameters:

c - the component to be removed.

resume

public void resume()

Description copied from interface: Suspendable

Resumes this suspendable component.

Specified by:

resume in interface Suspendable

Overrides:

resume in class EmptyComponent

start

public void start(java.beans.PropertyChangeEvent incoming)

Description copied from interface: Startable

Starts this startable component.

Specified by:

start in interface Startable

Overrides:

start in class EmptyComponent

Parameters:

incoming - the event that triggered the invocation of this method. May be null.

stop

public void stop()

Description copied from interface: Startable

Stops this startable component.

Specified by:

stop in interface Startable

Overrides:

stop in class EmptyComponent

suspend

public void suspend()

Description copied from interface: Suspendable

Suspends this suspendable component.

Specified by:

suspend in interface Suspendable

Overrides:

suspend in class EmptyComponent

switchToFirstComponent

protected void switchToFirstComponent()

Switches to the first component in the sequence.

switchToNextComponent

protected void switchToNextComponent()

Switches to the next component in the sequence.