infosapient.system
Class ObservableImpl

java.lang.Object
  |
  +--infosapient.system.ObservableImpl

Direct Known Subclasses:

FzySystemComponent, InfoSapientController, InfoSapientRuleEditor.RuleEditorObservable

public class ObservableImpl

extends java.lang.Object

implements Observable

This class represents an observable object, or "data" in the model-view paradigm.

An observable object can have one or more observers. After an observable instance changes, an application calling the Observable's notifyObservers method causes all of its observers to be notified of the change by a call to their update method.

Version:

$Revision: 1.1.1.1 $

See Also:

Serialized Form

Field Summary

private Observer[]	arr
private boolean	changed
private java.util.Vector	obs
(package private) static long	serialVersionUID

Constructor Summary

ObservableImpl()
Construct an Observable with zero Observers

Method Summary

void	addObserver(Observer o) Adds an observer to the set of observers for this object.
void	clearChanged() Indicates that this object has no longer changed, or that it has already notified all of its observers of its most recent change.
boolean	containsObserver(Observer o) Test if the Observer exists within the list of observers of this object.
int	countObservers() Returns the number of observers of this object.
void	deleteObserver(Observer o) Deletes an observer from the set of observers of this object.
void	deleteObservers() Clears the observer list so that this object no longer has any observers.
boolean	hasChanged() Tests if this object has changed.
void	notifyObservers() If this object has changed, as indicated by the hasChanged method, then notify all of its observers and then call the clearChanged method to indicate that this object has no longer changed.
void	notifyObservers(java.lang.Object arg) If this object has changed, as indicated by the hasChanged method, then notify all of its observers and then call the clearChanged method to indicate that this object has no longer changed.
void	setChanged() Indicates that this object has changed.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

static final long serialVersionUID

changed

private boolean changed

obs

private java.util.Vector obs

arr

private Observer[] arr

Constructor Detail

ObservableImpl

public ObservableImpl()

Construct an Observable with zero Observers

Method Detail

addObserver

public void addObserver(Observer o)

Adds an observer to the set of observers for this object.

Specified by:

addObserver in interface Observable

Parameters:

o - an observer to be added.

Since:

JDK1.0

clearChanged

public void clearChanged()

Indicates that this object has no longer changed, or that it has already notified all of its observers of its most recent change. This method is called automatically by the notifyObservers methods.

Specified by:

clearChanged in interface Observable

Since:

JDK1.0

See Also:

infosapient.system.Observable#notifyObservers(), Observable.notifyObservers(java.lang.Object)

containsObserver

public boolean containsObserver(Observer o)

Test if the Observer exists within the list of observers of this object.

Specified by:

containsObserver in interface Observable

Parameters:

the - object to be tested.

Returns:

true if the object exists within the list of observers; else false

Since:

JDK1.0

countObservers

public int countObservers()

Returns the number of observers of this object.

Specified by:

countObservers in interface Observable

Returns:

the number of observers of this object.

Since:

JDK1.0

deleteObserver

public void deleteObserver(Observer o)

Deletes an observer from the set of observers of this object.

Specified by:

deleteObserver in interface Observable

Parameters:

o - the observer to be deleted.

Since:

JDK1.0

deleteObservers

public void deleteObservers()

Clears the observer list so that this object no longer has any observers.

Specified by:

deleteObservers in interface Observable

Since:

JDK1.0

hasChanged

public boolean hasChanged()

Tests if this object has changed.

Specified by:

hasChanged in interface Observable

Returns:

true if the setChanged method has been called more recently than the clearChanged method on this object; false otherwise.

Since:

JDK1.0

See Also:

Observable.clearChanged(), Observable.setChanged()

notifyObservers

public void notifyObservers()

If this object has changed, as indicated by the hasChanged method, then notify all of its observers and then call the clearChanged method to indicate that this object has no longer changed.

Each observer has its update method called with two arguments: this observable object and null.

Since:

JDK1.0

See Also:

Observable.clearChanged(), Observable.hasChanged(), Observer.update(infosapient.system.Observable, java.lang.Object)

notifyObservers

public void notifyObservers(java.lang.Object arg)

If this object has changed, as indicated by the hasChanged method, then notify all of its observers and then call the clearChanged method to indicate that this object has no longer changed.

Each observer has its update method called with two arguments: this observable object and the arg argument.

Specified by:

notifyObservers in interface Observable

Parameters:

arg - any object.

Since:

JDK1.0

See Also:

Observable.clearChanged(), Observable.hasChanged(), Observer.update(infosapient.system.Observable, java.lang.Object)

setChanged

public void setChanged()

Indicates that this object has changed.

Specified by:

setChanged in interface Observable

Since:

JDK1.0