org.puremvc.java.core
Class View

java.lang.Object
  org.puremvc.java.core.View

All Implemented Interfaces:

IView

public class View
extends java.lang.Object
implements IView

A Singleton IView implementation.

In PureMVC, the View class assumes these responsibilities:

• Maintain a cache of IMediator instances.
• Provide methods for registering, retrieving, and removing IMediators.
• Managing the observer lists for each INotification in the application.
• Providing a method for attaching IObservers to an INotification's observer list.
• Providing a method for broadcasting an INotification.
• Notifying the IObservers of a given INotification when it broadcast.

See Also:

Mediator, Observer, Notification

Constructor Summary

protected

View() Constructor.

Method Summary

static View	getInstance() View Singleton Factory method.
boolean	hasMediator(java.lang.String mediatorName) Check if a Mediator is registered or not
protected void	initializeView() Initialize the Singleton View instance.
void	notifyObservers(INotification note) Notify the Observers for a particular Notification.
void	registerMediator(IMediator mediator) Register an Mediator instance with the View.
void	registerObserver(java.lang.String notificationName, IObserver observer) Register an Observer to be notified of INotifications with a given name.
IMediator	removeMediator(java.lang.String mediatorName) Remove an Mediator from the View.
void	removeObserver(java.lang.String notificationName, java.lang.Object notifyContext) Remove the observer for a given notifyContext from an observer list for a given Notification name.
IMediator	retrieveMediator(java.lang.String mediatorName) Retrieve an Mediator from the View.

Methods inherited from class java.lang.Object

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

Constructor Detail

View

protected View()

Constructor.

This IView implementation is a Singleton, so you should not call the constructor directly, but instead call the static Singleton Factory method View.getInstance()

Throws:

java.lang.Error - Error if Singleton instance has already been constructed

Method Detail

initializeView

protected void initializeView()

Initialize the Singleton View instance.

Called automatically by the constructor, this is your opportunity to initialize the Singleton instance in your subclass without overriding the constructor.

getInstance

public static View getInstance()

View Singleton Factory method.

Returns:

The Singleton instance of View

notifyObservers

public void notifyObservers(INotification note)

Notify the Observers for a particular Notification.

All previously attached Observers for this Notification's list are notified and are passed a reference to the Notification in the order in which they were registered.

Specified by:

notifyObservers in interface IView

Parameters:

note - the Notification to notify Observers of.

removeObserver

public void removeObserver(java.lang.String notificationName,
                           java.lang.Object notifyContext)

Remove the observer for a given notifyContext from an observer list for a given Notification name.

Parameters:

notificationName - Which observer list to remove from

notifyContext - Remove the observer with this object as its notifyContext

registerMediator

public void registerMediator(IMediator mediator)

Register an Mediator instance with the View.

Registers the Mediator so that it can be retrieved by name, and further interrogates the Mediator for its Notification interests.

If the Mediator returns any Notification names to be notified about, an Observer is created encapsulating the Mediator instance's handleNotification method and registering it as an Observer for all Notifications the Mediator is interested in.

Specified by:

registerMediator in interface IView

Parameters:

mediator - the name to associate with this IMediator instance

registerObserver

public void registerObserver(java.lang.String notificationName,
                             IObserver observer)

Register an Observer to be notified of INotifications with a given name.

Specified by:

registerObserver in interface IView

Parameters:

notificationName - the name of the Notifications to notify this Observer of

observer - the Observer to register

removeMediator

public IMediator removeMediator(java.lang.String mediatorName)

Remove an Mediator from the View.

Specified by:

removeMediator in interface IView

Parameters:

mediatorName - name of the Mediator instance to be removed.

retrieveMediator

public IMediator retrieveMediator(java.lang.String mediatorName)

Retrieve an Mediator from the View.

Specified by:

retrieveMediator in interface IView

Parameters:

mediatorName - the name of the Mediator instance to retrieve.

Returns:

the Mediator instance previously registered with the given mediatorName.

hasMediator

public boolean hasMediator(java.lang.String mediatorName)

Check if a Mediator is registered or not

Specified by:

hasMediator in interface IView

Parameters:

mediatorName -

Returns:

whether a Mediator is registered with the given mediatorName.