edu.luc.cs.trull
Class Switch

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.Switch

All Implemented Interfaces:

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

Direct Known Subclasses:

If

public class Switch
extends AbstractCombinator

A data-driven selection mechanism that immediately evaluates its valuator (criterium) and chooses the corresponding branch. The resulting component terminates when the chosen branch terminates.

Nested Class Summary

protected class	Switch.LocalListener A dedicated listener that forwards the event to all external listeners.
protected class	Switch.SwitchTerminationListener This component terminates as soon as the chosen branch component terminates.

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

AbstractCombinator.DefaultTerminationListener

Field Summary

private int	currentComponentIndex The index of the chosen branch.
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 for this component.
private EventValuator	valuator The valuator (criterium) for this switch.

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

components

Constructor Summary

Switch()
Constructs a Switch component.

Switch(EventValuator valuator, Component[] components)
Constructs a Switch component.

Method Summary

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() The chosen branch comopnent.
EventValuator	getValuator() Returns the criterium used by this Switch.
void	propertyChange(java.beans.PropertyChangeEvent evt) This method forwards events received from external sources to the components of this combinator.
void	removeComponent(Component c) Removes the specified component from this combinator.
void	resume() Resumes this suspendable component.
void	setValuator(EventValuator valuator) Sets the criterium of this Switch to the given valuator.
void	start(java.beans.PropertyChangeEvent incoming) Starts this startable component.
void	stop() Stops this startable component.
void	suspend() Suspends this suspendable component.
protected void	switchToComponent(int choice) Switches to the branch component with the given index.

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 chosen branch.

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 for this component.

valuator

private EventValuator valuator

The valuator (criterium) for this switch.

Constructor Detail

Switch

public Switch()

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

Switch

public Switch(EventValuator valuator,
              Component[] components)

Constructs a Switch component.

Parameters:

valuator - the criterium used to choose a branch.

components - the array of branch components.

Method Detail

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()

The chosen branch comopnent.

Returns:

the chosen branch comopnent.

getValuator

public EventValuator getValuator()

Returns the criterium used by this Switch.

Returns:

the valuator used as the criterium.

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent evt)

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

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

setValuator

public void setValuator(EventValuator valuator)

Sets the criterium of this Switch to the given valuator.

Parameters:

valuator - the valuator to be used as the criterium.

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

switchToComponent

protected void switchToComponent(int choice)

Switches to the branch component with the given index.

Parameters:

choice - the index of the branch.