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// Copyright 2010 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//      http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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 * @fileoverview A MessageChannel decorator that wraps a deferred MessageChannel
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 * and enqueues messages and service registrations until that channel exists.
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 *
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 */
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goog.provide('goog.messaging.DeferredChannel');
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goog.require('goog.Disposable');
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goog.require('goog.messaging.MessageChannel');  // interface
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/**
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 * Creates a new DeferredChannel, which wraps a deferred MessageChannel and
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 * enqueues messages to be sent once the wrapped channel is resolved.
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 *
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 * @param {!goog.async.Deferred<!goog.messaging.MessageChannel>} deferredChannel
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 *     The underlying deferred MessageChannel.
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 * @constructor
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 * @extends {goog.Disposable}
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 * @implements {goog.messaging.MessageChannel}
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 * @final
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 */
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goog.messaging.DeferredChannel = function(deferredChannel) {
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  goog.messaging.DeferredChannel.base(this, 'constructor');
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  /** @private {!goog.async.Deferred<!goog.messaging.MessageChannel>} */
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  this.deferred_ = deferredChannel;
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};
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goog.inherits(goog.messaging.DeferredChannel, goog.Disposable);
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/**
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 * Cancels the wrapped Deferred.
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 */
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goog.messaging.DeferredChannel.prototype.cancel = function() {
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  this.deferred_.cancel();
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.connect = function(opt_connectCb) {
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  if (opt_connectCb) {
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    opt_connectCb();
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  }
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.isConnected = function() {
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  return true;
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.registerService = function(
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    serviceName, callback, opt_objectPayload) {
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  this.deferred_.addCallback(function(resolved) {
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    resolved.registerService(serviceName, callback, opt_objectPayload);
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  });
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.registerDefaultService = function(
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    callback) {
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  this.deferred_.addCallback(function(resolved) {
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    resolved.registerDefaultService(callback);
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  });
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.send = function(serviceName, payload) {
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  this.deferred_.addCallback(function(resolved) {
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    resolved.send(serviceName, payload);
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  });
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};
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/** @override */
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goog.messaging.DeferredChannel.prototype.disposeInternal = function() {
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  this.cancel();
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  goog.messaging.DeferredChannel.base(this, 'disposeInternal');
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};
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