source: trunk/src/org/apollo/mvc/AbstractSubject.java@ 1102

package org.apollo.mvc;

import java.util.HashSet;
import java.util.Set;

import org.expeditee.gio.EcosystemManager;

/**
 * A Skeletal implementation of a Subject in the model-view-controller package.
 * 
 * @author Brook Novak
 */
public abstract class AbstractSubject implements Subject {

        /** Collection of registered observers. */
        protected Set<Observer> observers = new HashSet <Observer>();

        /**
         * Adds an observer to the set of registered observers.
         * @param ob The observer to add.
         */
        public final void addObserver(final Observer ob) {
        synchronized (observers) {
                observers.add(ob);
        }
                ob.setObservedSubject(this);
        }

        /**
         * Removes an observer from the set of registered observers.
         * 
         * @param ob The observer to remove
         */
        public final void removeObserver(final Observer ob) {
        synchronized (observers) {
                observers.remove(ob);
        }
                ob.setObservedSubject(null);
        }

        /**
         * Notifies all observers that this object has changed with the given
         * ModelChangeEvent.
         * 
         * @param event
         *            A ModelChangeEvent which specifies how this object has
         *            changed.
         */
        protected final void fireSubjectChanged(final SubjectChangedEvent event) {
        
        synchronized (observers) {
                for (Observer ob : observers) {
                        ob.modelChanged(this, event);
                }
        }
        }
        
        /**
         * Notifies all observers that this object has changed with the given
         * ModelChangeEvent. On the swing thread.
         * 
         * @param event
         *            A ModelChangeEvent which specifies how this object has
         *            changed.
         */
        protected final void fireSubjectChangedLaterOnSwingThread(final SubjectChangedEvent event) {
                
                EcosystemManager.getMiscManager().runOnGIOThread(new Runnable() {
                        public void run() {
                                fireSubjectChanged(event);
                        }
                });
                
        }
        
}