package cz.cuni.amis.pogamut.base.utils.collections.adapters;
   
   import java.util.HashSet;
   
   import cz.cuni.amis.pogamut.base.communication.worldview.IWorldView;
   import cz.cuni.amis.pogamut.base.communication.worldview.object.IWorldObjectEventListener;
   import cz.cuni.amis.pogamut.base3d.worldview.object.IViewable;
   import cz.cuni.amis.pogamut.base3d.worldview.object.event.WorldObjectAppearedEvent;
   import cz.cuni.amis.pogamut.base3d.worldview.object.event.WorldObjectDisappearedEvent;
  import cz.cuni.amis.utils.collections.ObservableSet;
  
  /**
   * Provides set of all visible world objects extending some class as observable set.
   * @author ik
   */
  public class WVVisibleObjectsSetAdapter<T extends IViewable> extends ObservableSet<T> {
  
      IWorldObjectEventListener<T, WorldObjectAppearedEvent<T>> addListener;
      IWorldObjectEventListener<T, WorldObjectDisappearedEvent<T>> remListener;
  
  	public WVVisibleObjectsSetAdapter(Class<T> objectClass, IWorldView worldView) {
          super(new HashSet<T>());
          // register listener
          worldView.addObjectListener(
          	objectClass, 
          	WorldObjectAppearedEvent.class,
          	addListener = new IWorldObjectEventListener<T, WorldObjectAppearedEvent<T>>() {
  
              @Override
              public void notify(WorldObjectAppearedEvent<T> event) {
                  add(event.getObject());
              }
          });
  
          worldView.addObjectListener(
          	objectClass,
          	WorldObjectDisappearedEvent.class,
          	remListener = new IWorldObjectEventListener<T, WorldObjectDisappearedEvent<T>>() {
  	            @Override
  	            public void notify(WorldObjectDisappearedEvent<T> event) {
  	                remove(event.getObject());
  	            }
          	}
          );
  
          // add the data
          synchronized(worldView.getAll(objectClass)) {
          	addAll(worldView.getAll(objectClass).values());
          }
      }
  }