preferences.js revision dc0f95d653279beabeb9817299e2902918ba123e 
1// Copyright (c) 2011 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
5cr.define('options', function() {
6
7  /////////////////////////////////////////////////////////////////////////////
8  // Preferences class:
9
10  /**
11   * Preferences class manages access to Chrome profile preferences.
12   * @constructor
13   */
14  function Preferences() {
15  }
16
17  cr.addSingletonGetter(Preferences);
18
19  /**
20   * Sets value of a boolean preference.
21   * and signals its changed value.
22   * @param {string} name Preference name.
23   * @param {boolean} value New preference value.
24   * @param {string} metric User metrics identifier.
25   */
26  Preferences.setBooleanPref = function(name, value, metric) {
27    var argumentList = [name, Boolean(value)];
28    if (metric != undefined) argumentList.push(metric);
29    chrome.send('setBooleanPref', argumentList);
30  };
31
32  /**
33   * Sets value of an integer preference.
34   * and signals its changed value.
35   * @param {string} name Preference name.
36   * @param {number} value New preference value.
37   * @param {string} metric User metrics identifier.
38   */
39  Preferences.setIntegerPref = function(name, value, metric) {
40    var argumentList = [name, Number(value)];
41    if (metric != undefined) argumentList.push(metric);
42    chrome.send('setIntegerPref', argumentList);
43  };
44
45  /**
46   * Sets value of a double-valued preference.
47   * and signals its changed value.
48   * @param {string} name Preference name.
49   * @param {number} value New preference value.
50   * @param {string} metric User metrics identifier.
51   */
52  Preferences.setDoublePref = function(name, value, metric) {
53    var argumentList = [name, Number(value)];
54    if (metric != undefined) argumentList.push(metric);
55    chrome.send('setDoublePref', argumentList);
56  };
57
58  /**
59   * Sets value of a string preference.
60   * and signals its changed value.
61   * @param {string} name Preference name.
62   * @param {string} value New preference value.
63   * @param {string} metric User metrics identifier.
64   */
65  Preferences.setStringPref = function(name, value, metric) {
66    var argumentList = [name, String(value)];
67    if (metric != undefined) argumentList.push(metric);
68    chrome.send('setStringPref', argumentList);
69  };
70
71  /**
72   * Sets value of a JSON list preference.
73   * and signals its changed value.
74   * @param {string} name Preference name.
75   * @param {Array} value New preference value.
76   * @param {string} metric User metrics identifier.
77   */
78  Preferences.setListPref = function(name, value, metric) {
79    var argumentList = [name, JSON.stringify(value)];
80    if (metric != undefined) argumentList.push(metric);
81    chrome.send('setListPref', argumentList);
82  };
83
84  /**
85   * Clears value of a JSON preference.
86   * @param {string} name Preference name.
87   * @param {string} metric User metrics identifier.
88   */
89  Preferences.clearPref = function(name, metric) {
90    var argumentList = [name];
91    if (metric != undefined) argumentList.push(metric);
92    chrome.send('clearPref', argumentList);
93  };
94
95  Preferences.prototype = {
96    __proto__: cr.EventTarget.prototype,
97
98    // Map of registered preferences.
99    registeredPreferences_: {},
100
101    /**
102     * Adds an event listener to the target.
103     * @param {string} type The name of the event.
104     * @param {!Function|{handleEvent:Function}} handler The handler for the
105     *     event. This is called when the event is dispatched.
106     */
107    addEventListener: function(type, handler) {
108      cr.EventTarget.prototype.addEventListener.call(this, type, handler);
109      this.registeredPreferences_[type] = true;
110    },
111
112    /**
113     * Initializes preference reading and change notifications.
114     */
115    initialize: function() {
116      var params1 = ['Preferences.prefsFetchedCallback'];
117      var params2 = ['Preferences.prefsChangedCallback'];
118      for (var prefName in this.registeredPreferences_) {
119        params1.push(prefName);
120        params2.push(prefName);
121      }
122      chrome.send('fetchPrefs', params1);
123      chrome.send('observePrefs', params2);
124    },
125
126    /**
127     * Helper function for flattening of dictionary passed via fetchPrefs
128     * callback.
129     * @param {string} prefix Preference name prefix.
130     * @param {object} dict Map with preference values.
131     */
132    flattenMapAndDispatchEvent_: function(prefix, dict) {
133      for (var prefName in dict) {
134        if (typeof dict[prefName] == 'object' &&
135            !this.registeredPreferences_[prefix + prefName]) {
136          this.flattenMapAndDispatchEvent_(prefix + prefName + '.',
137              dict[prefName]);
138        } else {
139          var event = new cr.Event(prefix + prefName);
140          event.value = dict[prefName];
141          this.dispatchEvent(event);
142        }
143      }
144    }
145  };
146
147  /**
148   * Callback for fetchPrefs method.
149   * @param {object} dict Map of fetched property values.
150   */
151  Preferences.prefsFetchedCallback = function(dict) {
152    Preferences.getInstance().flattenMapAndDispatchEvent_('', dict);
153  };
154
155  /**
156   * Callback for observePrefs method.
157   * @param {array} notification An array defining changed preference values.
158   * notification[0] contains name of the change preference while its new value
159   * is stored in notification[1].
160   */
161  Preferences.prefsChangedCallback = function(notification) {
162    var event = new cr.Event(notification[0]);
163    event.value = notification[1];
164    Preferences.getInstance().dispatchEvent(event);
165  };
166
167  // Export
168  return {
169    Preferences: Preferences
170  };
171
172});
173