RegisteredListenersSupplier.java

package sk.stuba.fiit.perconik.core.preferences;

import java.util.Set;

import sk.stuba.fiit.perconik.core.Listener;
import sk.stuba.fiit.perconik.core.persistence.Registrations;
import sk.stuba.fiit.perconik.core.services.listeners.ListenerClassesSupplier;

/**
 * A class that supplies classes of currently registered
 * listeners based on {@link ListenerPreferences}.
 *
 * @author Pavol Zbell
 * @since 1.0
 */
public final class RegisteredListenersSupplier implements ListenerClassesSupplier {
  /**
   * The constructor.
   */
  public RegisteredListenersSupplier() {}

  /**
   * Gets classes of registered listeners according to the current
   * state of <i>instance</i> scope of {@code ListenerPreferences}.
   * @return classes of registered listeners
   */
  public Set<Class<? extends Listener>> get() {
    ListenerPreferences preferences = ListenerPreferences.getShared();

    return Registrations.toListenerClasses(Registrations.marked(preferences.getListenerPersistenceData()));
  }
}