org.escot
Class OnDemandFeatureSupport

java.lang.Object
  |
  +--org.escot.OnDemandFeatureSupport

All Implemented Interfaces:

BeanWiringListener

public class OnDemandFeatureSupport

extends Object

implements BeanWiringListener

This is a utility class that may be used by beans which are ExplicitFeatureProviders that need to duplicate features when they are wired and remove them when they are unwired. You can use an instance of this class as a member field of your bean and delegate wiring listening to it. The bean should implement BeanWiringListener.

Field Summary

protected ExplicitFeatureProvider	mBean
protected com.sun.java.util.collections.HashSet	mClasses

Constructor Summary

OnDemandFeatureSupport(ExplicitFeatureProvider bean)

OnDemandFeatureSupport(ExplicitFeatureProvider bean, Class featureClass)
Constructor that specifies the bean and a class of instances that should be duplicated when wired to and removed when unwired.

Method Summary

void	addFeatureClass(Class featureClass) Adds a class of instances that should be duplicated when wired and removed when unwired.
protected void	expandFeatureSet(EscotFeature targetFeature, EscotFeature associatedFeature, Wire wire) Expands the feature set when a feature belonging to the bean that is an instance of one of the classes designated for expansion, has been wired.
protected String	generateWiredFeatureName(EscotFeature targetFeature, EscotFeature associatedFeature, Wire wire) Override this if a feature that has been wired should be renamed.
protected Object	newFeature(EscotFeature feat) Creates a new feature based on the specified feature.
protected void	registerFeature(Object feat) Adds the feature to the registry.
void	removeFeatureClass(Class featureClass) Removes a class of instances that should be duplicated when wired and removed when unwired.
protected void	unregisterFeature(Object feat) Removes the feature from the registry.
void	wireAdded(BeanWiringEvent evt) Invoked when a wire has been added involving the bean.
void	wireRemoved(BeanWiringEvent e) Invoked when a wire has been removed involving the bean.

Methods inherited from class java.lang.Object

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

Field Detail

mBean

protected ExplicitFeatureProvider mBean

mClasses

protected com.sun.java.util.collections.HashSet mClasses

Constructor Detail

OnDemandFeatureSupport

public OnDemandFeatureSupport(ExplicitFeatureProvider bean)

OnDemandFeatureSupport

public OnDemandFeatureSupport(ExplicitFeatureProvider bean,
                              Class featureClass)

Constructor that specifies the bean and a class of instances that should be duplicated when wired to and removed when unwired.

Method Detail

addFeatureClass

public void addFeatureClass(Class featureClass)

Adds a class of instances that should be duplicated when wired and removed when unwired.

removeFeatureClass

public void removeFeatureClass(Class featureClass)

Removes a class of instances that should be duplicated when wired and removed when unwired.

wireAdded

public void wireAdded(BeanWiringEvent evt)

Invoked when a wire has been added involving the bean. Calls expandFeatureSet to expand the number of features.

Specified by:

wireAdded in interface BeanWiringListener

wireRemoved

public void wireRemoved(BeanWiringEvent e)

Invoked when a wire has been removed involving the bean. If the bean is the subscriber in the wire and the subscriber feature is an expandable feature class, the feature is removed from the registry using unregisterFeature.

Specified by:

wireRemoved in interface BeanWiringListener

expandFeatureSet

protected void expandFeatureSet(EscotFeature targetFeature,
                                EscotFeature associatedFeature,
                                Wire wire)

Expands the feature set when a feature belonging to the bean that is an instance of one of the classes designated for expansion, has been wired. Renames the feature, getting the new name by calling generateWiredFeatureName, creates a duplicate feature by calling newFeature, and adds it to the registry by calling registerFeature.

generateWiredFeatureName

protected String generateWiredFeatureName(EscotFeature targetFeature,
                                          EscotFeature associatedFeature,
                                          Wire wire)

Override this if a feature that has been wired should be renamed. The default implementation returns the name of the feature, so it will be unchanged.

newFeature

protected Object newFeature(EscotFeature feat)
                     throws InstantiationException,
                            IllegalAccessException

Creates a new feature based on the specified feature. If this method returns null or throws one of the declared exceptions, OnDemandFeatureSupport does not register a duplicate feature.

registerFeature

protected void registerFeature(Object feat)

Adds the feature to the registry.

unregisterFeature

protected void unregisterFeature(Object feat)

Removes the feature from the registry. Override this if you don't want the feature to be removed.