/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project licenses this file to you 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.jboss.netty.channel;
  
  import static org.jboss.netty.channel.Channels.*;
  
  /**
   * The default {@link ChildChannelStateEvent} implementation.
   */
  public class DefaultChildChannelStateEvent implements ChildChannelStateEvent {
  
      private final Channel parentChannel;
      private final Channel childChannel;
  
      /**
       * Creates a new instance.
       */
      public DefaultChildChannelStateEvent(Channel parentChannel, Channel childChannel) {
          if (parentChannel == null) {
              throw new NullPointerException("parentChannel");
          }
          if (childChannel == null) {
              throw new NullPointerException("childChannel");
          }
          this.parentChannel = parentChannel;
          this.childChannel = childChannel;
      }
  
      public Channel getChannel() {
          return parentChannel;
      }
  
      public ChannelFuture getFuture() {
          return succeededFuture(getChannel());
      }
  
      public Channel getChildChannel() {
          return childChannel;
      }
  
      @Override
      public String toString() {
          String channelString = getChannel().toString();
          StringBuilder buf = new StringBuilder(channelString.length() + 32);
          buf.append(channelString);
          buf.append(getChildChannel().isOpen()? " CHILD_OPEN: " : " CHILD_CLOSED: ");
          buf.append(getChildChannel().getId());
          return buf.toString();
      }
  }