Options2: Pull the trigger.

chrome/browser/resources/options2/preferences.js

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.define('options', function() {
+
+  /////////////////////////////////////////////////////////////////////////////
+  // Preferences class:
+
+  /**
+   * Preferences class manages access to Chrome profile preferences.
+   * @constructor
+   */
+  function Preferences() {
+  }
+
+  cr.addSingletonGetter(Preferences);
+
+  /**
+   * Sets value of a boolean preference.
+   * and signals its changed value.
+   * @param {string} name Preference name.
+   * @param {boolean} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setBooleanPref = function(name, value, metric) {
+    var argumentList = [name, Boolean(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setBooleanPref', argumentList);
+  };
+
+  /**
+   * Sets value of an integer preference.
+   * and signals its changed value.
+   * @param {string} name Preference name.
+   * @param {number} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setIntegerPref = function(name, value, metric) {
+    var argumentList = [name, Number(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setIntegerPref', argumentList);
+  };
+
+  /**
+   * Sets value of a double-valued preference.
+   * and signals its changed value.
+   * @param {string} name Preference name.
+   * @param {number} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setDoublePref = function(name, value, metric) {
+    var argumentList = [name, Number(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setDoublePref', argumentList);
+  };
+
+  /**
+   * Sets value of a string preference.
+   * and signals its changed value.
+   * @param {string} name Preference name.
+   * @param {string} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setStringPref = function(name, value, metric) {
+    var argumentList = [name, String(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setStringPref', argumentList);
+  };
+
+  /**
+   * Sets value of a string preference that represents a URL
+   * and signals its changed value. The value will be fixed to be a valid URL.
+   * @param {string} name Preference name.
+   * @param {string} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setURLPref = function(name, value, metric) {
+    var argumentList = [name, String(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setURLPref', argumentList);
+  };
+
+  /**
+   * Sets value of a JSON list preference.
+   * and signals its changed value.
+   * @param {string} name Preference name.
+   * @param {Array} value New preference value.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.setListPref = function(name, value, metric) {
+    var argumentList = [name, JSON.stringify(value)];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('setListPref', argumentList);
+  };
+
+  /**
+   * Clears value of a JSON preference.
+   * @param {string} name Preference name.
+   * @param {string} metric User metrics identifier.
+   */
+  Preferences.clearPref = function(name, metric) {
+    var argumentList = [name];
+    if (metric != undefined) argumentList.push(metric);
+    chrome.send('clearPref', argumentList);
+  };
+
+  Preferences.prototype = {
+    __proto__: cr.EventTarget.prototype,
+
+    // Map of registered preferences.
+    registeredPreferences_: {},
+
+    /**
+     * Adds an event listener to the target.
+     * @param {string} type The name of the event.
+     * @param {!Function|{handleEvent:Function}} handler The handler for the
+     *     event. This is called when the event is dispatched.
+     */
+    addEventListener: function(type, handler) {
+      cr.EventTarget.prototype.addEventListener.call(this, type, handler);
+      this.registeredPreferences_[type] = true;
+    },
+
+    /**
+     * Initializes preference reading and change notifications.
+     */
+    initialize: function() {
+      var params1 = ['Preferences.prefsFetchedCallback'];
+      var params2 = ['Preferences.prefsChangedCallback'];
+      for (var prefName in this.registeredPreferences_) {
+        params1.push(prefName);
+        params2.push(prefName);
+      }
+      chrome.send('fetchPrefs', params1);
+      chrome.send('observePrefs', params2);
+    },
+
+    /**
+     * Helper function for flattening of dictionary passed via fetchPrefs
+     * callback.
+     * @param {string} prefix Preference name prefix.
+     * @param {object} dict Map with preference values.
+     */
+    flattenMapAndDispatchEvent_: function(prefix, dict) {
+      for (var prefName in dict) {
+        if (typeof dict[prefName] == 'object' &&
+            !this.registeredPreferences_[prefix + prefName]) {
+          this.flattenMapAndDispatchEvent_(prefix + prefName + '.',
+              dict[prefName]);
+        } else {
+          var event = new cr.Event(prefix + prefName);
+          event.value = dict[prefName];
+          this.dispatchEvent(event);
+        }
+      }
+    }
+  };
+
+  /**
+   * Callback for fetchPrefs method.
+   * @param {object} dict Map of fetched property values.
+   */
+  Preferences.prefsFetchedCallback = function(dict) {
+    Preferences.getInstance().flattenMapAndDispatchEvent_('', dict);
+  };
+
+  /**
+   * Callback for observePrefs method.
+   * @param {array} notification An array defining changed preference values.
+   * notification[0] contains name of the change preference while its new value
+   * is stored in notification[1].
+   */
+  Preferences.prefsChangedCallback = function(notification) {
+    var event = new cr.Event(notification[0]);
+    event.value = notification[1];
+    Preferences.getInstance().dispatchEvent(event);
+  };
+
+  // Export
+  return {
+    Preferences: Preferences
+  };
+
+});