public class IdeSubject extends java.lang.Object implements Subject
IdeSubject
class defines the API to register
Observer
s 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 Subject
observed
- the subject whose state has changed.change
- what changed.