public class IdeSubject extends java.lang.Object implements Subject
IdeSubject class defines the API to register
  Observers that are interested in receiving notifications
  of Subject changes.
  Classes that can have multiple views in particular must implement
  the Subject interface so that all observing views can be
  notified when changes have occurred.Observer, 
UpdateMessage| Constructor and Description | 
|---|
IdeSubject()  | 
| Modifier and Type | Method and Description | 
|---|---|
void | 
attach(Observer observer)
Registers an  
Observer interested in being notified when the 
 internal state of the class implementing the Subject 
 interface changes. | 
void | 
detach(Observer observer)
Unregisters an observer that is not interested anymore in being notified
 when the internal state of the class implementing the  
Subject
 interface changes. | 
void | 
notifyObservers(java.lang.Object observed,
               UpdateMessage change)
Notifies all observers that the state of the subject has changed. 
 | 
public final void attach(Observer observer)
Observer interested in being notified when the 
 internal state of the class implementing the Subject 
 interface changes. If the observer is already attached, this method
 does nothing.public final void detach(Observer observer)
Subject
 interface changes.public final void notifyObservers(java.lang.Object observed,
                   UpdateMessage change)
notifyObservers in interface Subjectobserved - the subject whose state has changed.change - what changed.