Package org.puremvc.java.interfaces

Interface IMediator

All Superinterfaces:
INotifier
All Known Implementing Classes:
Mediator
public interface IMediator
extends INotifier

The interface definition for a PureMVC Mediator.

In PureMVC, IMediator implementors assume these responsibilities:

  • Implement a common method which returns a list of all INotifications the IMediator has interest in.
  • Implement a notification callback method.
  • Implement methods that are called when the IMediator is registered or removed from the View.

Additionally, IMediators typically:

  • Act as an intermediary between one or more view components such as text boxes or list controls, maintaining references and coordinating their behavior.
  • In Flash-based apps, this is often the place where event listeners are added to view components, and their handlers implemented.
  • Respond to and generate INotifications, interacting with of the rest of the PureMVC app.

When an IMediator is registered with the IView, the IView will call the IMediator's listNotificationInterests method. The IMediator will return an Array of INotification names which it wishes to be notified about.

The IView will then create an Observer object encapsulating that IMediator's (handleNotification) method and register it as an Observer for each INotification name returned by listNotificationInterests.

A concrete IMediator implementor usually looks something like this:

 import org.puremvc.as3.multicore.patterns.mediator.*;
 import org.puremvc.as3.multicore.patterns.observer.*;
 import org.puremvc.as3.multicore.core.view.*;

 import com.me.myapp.model.*;
 import com.me.myapp.view.*;
 import com.me.myapp.controller.*;

 import javax.swing.JComboBox;
 import java.awt.event.ActionListener;

 public class MyMediator extends Mediator implements IMediator, ActionListener {

     public MyMediator( Object viewComponent ) {
         super( viewComponent );
         combo.addActionListener( this );
     }

     public String[] listNotificationInterests() {
         return [ MyFacade.SET_SELECTION,
                  MyFacade.SET_DATAPROVIDER ];
     }

     public void handleNotification( INotification notification ) {
         switch ( notification.getName() ) {
             case MyFacade.SET_SELECTION:
                 setSelection(notification);
                 break;
             case MyFacade.SET_DATAPROVIDER:
                 setDataProvider(notification);
                 break;
         }
     }

     // Set the data provider of the combo box
     protected void setDataProvider( INotification notification ) {
         combo.setModel(ComboBoxModel<String>(notification.getBody()));
     }

     // Invoked when the combo box dispatches a change event, we send a
     // notification with the
     public void actionPerformed(ActionEvent event) {
         sendNotification( MyFacade.MYCOMBO_CHANGED, this );
     }

     // A private getter for accessing the view object by class
     protected JComboBox getViewComponent() {
         return viewComponent;
     }

 }
See Also:
INotification

  • Method Details

    • getMediatorName

      java.lang.String getMediatorName()

      Get the IMediator instance name

      Returns:
      the IMediator instance name

    • getViewComponent

      java.lang.Object getViewComponent()

      Get the IMediator's view component.

      Returns:
      Object the view component

    • setViewComponent

      void setViewComponent​(java.lang.Object viewComponent)

      Set the IMediator's view component.

      Parameters:
      viewComponent - the view component

    • listNotificationInterests

      java.lang.String[] listNotificationInterests()

      List INotification interests.

      Returns:
      an Array of the INotification names this IMediator has an interest in.

    • handleNotification

      void handleNotification​(INotification notification)

      Handle an INotification.

      Parameters:
      notification - the INotification to be handled

    • onRegister

      void onRegister()

      Called by the View when the Mediator is registered

    • onRemove

      void onRemove()

      Called by the View when the Mediator is removed