text: // Copyright 2010 The Closure Library Authors. All Rights Reserved.
  //
  // 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.
  
  /**
   * @fileoverview A MessageChannel decorator that wraps a deferred MessageChannel
   * and enqueues messages and service registrations until that channel exists.
   *
   */
  
  goog.provide('goog.messaging.DeferredChannel');
  
  goog.require('goog.async.Deferred');
  goog.require('goog.messaging.MessageChannel'); // interface
  
  
  
  /**
   * Creates a new DeferredChannel, which wraps a deferred MessageChannel and
   * enqueues messages to be sent once the wrapped channel is resolved.
   *
   * @param {!goog.async.Deferred} deferredChannel The underlying deferred
   *     MessageChannel.
   * @constructor
   * @implements {goog.messaging.MessageChannel}
   */
  goog.messaging.DeferredChannel = function(deferredChannel) {
    this.deferred_ = deferredChannel;
  };
  
  
  /**
   * Cancels the wrapped Deferred.
   */
  goog.messaging.DeferredChannel.prototype.cancel = function() {
    this.deferred_.cancel();
  };
  
  
  /** @override */
  goog.messaging.DeferredChannel.prototype.connect = function(opt_connectCb) {
    if (opt_connectCb) {
      opt_connectCb();
    }
  };
  
  
  /** @override */
  goog.messaging.DeferredChannel.prototype.isConnected = function() {
    return true;
  };
  
  
  /** @override */
  goog.messaging.DeferredChannel.prototype.registerService = function(
      serviceName, callback, opt_objectPayload) {
    this.deferred_.addCallback(function(resolved) {
      resolved.registerService(serviceName, callback, opt_objectPayload);
    });
  };
  
  
  /** @override */
  goog.messaging.DeferredChannel.prototype.registerDefaultService =
      function(callback) {
    this.deferred_.addCallback(function(resolved) {
      resolved.registerDefaultService(callback);
    });
  };
  
  
  /** @override */
  goog.messaging.DeferredChannel.prototype.send = function(serviceName, payload) {
    this.deferred_.addCallback(function(resolved) {
      resolved.send(serviceName, payload);
    });
  };
  