/**
 * Copyright 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.waveprotocol.wave.model.conversation;

import org.waveprotocol.wave.model.wave.SourcesEvents;

/**
 * Extends {@link ManifestThread} to provide events that can be listened to.
 *
 * @author zdwang@google.com (David Wang)
 */
interface ObservableManifestThread extends ManifestThread,
    SourcesEvents<ObservableManifestThread.Listener>, HasId {
  /**
   * Receives events on a {@link ManifestThread}.
   */
  public interface Listener {
    /**
     * Called when a blip is added to the thread.
     */
    void onBlipAdded(ObservableManifestBlip blip);

    /**
     * Called when a blip is removed from the thread.
     */
    void onBlipRemoved(ObservableManifestBlip blip);
  }

  /**
   * Removes all listeners from this thread.
   */
  void detachListeners();

  // Covariant specialisations.

  @Override
  ObservableManifestBlip appendBlip(String id);

  @Override
  ObservableManifestBlip insertBlip(int index, String id);

  @Override
  ObservableManifestBlip getBlip(int index);

  @Override
  Iterable<? extends ObservableManifestBlip> getBlips();
}