SourcesEvents.java

/**
 * 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.wave;

/**
 * An object that emits events to registered listeners.
 *
 *
 */
public interface SourcesEvents<Listener> {
  /**
   * Adds a listener.  If the listener is already registered on this object,
   * this method has no effect.
   *
   * @param listener  listener to add
   */
  void addListener(Listener listener);

  /**
   * Removes a listener.  If the listener is not already registered on this
   * object, this method has no effect.
   *
   * @param listener  listener to remove
   */
  void removeListener(Listener listener);
}