chrome_sync.js revision c5cede9ae108bb15f6b7a8aea21c7e1fefa2834c 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// require cr.js
6// require cr/event_target.js
7// require cr/util.js
8
9cr.define('chrome.sync', function() {
10  'use strict';
11
12  /**
13   * A simple timer to measure elapsed time.
14   * @constructor
15   */
16  function Timer() {
17    /**
18     * The time that this Timer was created.
19     * @type {number}
20     * @private
21     * @const
22     */
23    this.start_ = Date.now();
24  }
25
26  /**
27   * @return {number} The elapsed seconds since this Timer was created.
28   */
29  Timer.prototype.getElapsedSeconds = function() {
30    return (Date.now() - this.start_) / 1000;
31  };
32
33  /** @return {!Timer} An object which measures elapsed time. */
34  var makeTimer = function() {
35    return new Timer;
36  };
37
38  /**
39   * @param {string} name The name of the event type.
40   * @param {!Object} details A collection of event-specific details.
41   */
42  var dispatchEvent = function(name, details) {
43    var e = new Event(name);
44    e.details = details;
45    chrome.sync.events.dispatchEvent(e);
46  };
47
48  /**
49   * Registers to receive a stream of events through
50   * chrome.sync.dispatchEvent().
51   */
52  var registerForEvents = function() {
53    chrome.send('registerForEvents');
54  };
55
56  /**
57   * Asks the browser to refresh our snapshot of sync state.  Should result
58   * in an onAboutInfoUpdated event being emitted.
59   */
60  var requestUpdatedAboutInfo = function() {
61    chrome.send('requestUpdatedAboutInfo');
62  };
63
64  /**
65   * Asks the browser to send us the list of registered types.  Should result
66   * in an onReceivedListOfTypes event being emitted.
67   */
68  var requestListOfTypes = function() {
69    chrome.send('requestListOfTypes');
70  };
71
72  /**
73   * Counter to uniquely identify requests while they're in progress.
74   * Used in the implementation of GetAllNodes.
75   */
76  var requestId = 0;
77
78  /**
79   * A map from counter values to asynchronous request callbacks.
80   * Used in the implementation of GetAllNodes.
81   * @type {{number: !Function}}
82   */
83  var requestCallbacks = {};
84
85  /**
86   * Asks the browser to send us a copy of all existing sync nodes.
87   * Will eventually invoke the given callback with the results.
88   *
89   * @param {function(!Object)} callback The function to call with the response.
90   */
91  var getAllNodes = function(callback) {
92    requestId++;
93    requestCallbacks[requestId] = callback;
94    chrome.send('getAllNodes', [requestId]);
95  };
96
97  /**
98   * Called from C++ with the response to a getAllNodes request.
99   * @param {number} id The requestId passed in with the request.
100   * @param {Object} response The response to the request.
101   */
102  var getAllNodesCallback = function(id, response) {
103    requestCallbacks[id](response);
104    requestCallbacks[id] = undefined;
105  };
106
107  return {
108    makeTimer: makeTimer,
109    dispatchEvent: dispatchEvent,
110    events: new cr.EventTarget(),
111    getAllNodes: getAllNodes,
112    getAllNodesCallback: getAllNodesCallback,
113    registerForEvents: registerForEvents,
114    requestUpdatedAboutInfo: requestUpdatedAboutInfo,
115    requestListOfTypes: requestListOfTypes,
116  };
117});
118