The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/dom/settings/SettingsChangeNotifier.jsm	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,123 @@
     1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
     1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
     1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
     1.7 +
     1.8 +"use strict"
     1.9 +
    1.10 +const DEBUG = false;
    1.11 +function debug(s) {
    1.12 +  if (DEBUG) dump("-*- SettingsChangeNotifier: " + s + "\n");
    1.13 +}
    1.14 +
    1.15 +const Cu = Components.utils;
    1.16 +const Cc = Components.classes;
    1.17 +const Ci = Components.interfaces;
    1.18 +
    1.19 +this.EXPORTED_SYMBOLS = ["SettingsChangeNotifier"];
    1.20 +
    1.21 +Cu.import("resource://gre/modules/XPCOMUtils.jsm");
    1.22 +Cu.import("resource://gre/modules/Services.jsm");
    1.23 +
    1.24 +const kXpcomShutdownObserverTopic      = "xpcom-shutdown";
    1.25 +const kMozSettingsChangedObserverTopic = "mozsettings-changed";
    1.26 +const kFromSettingsChangeNotifier      = "fromSettingsChangeNotifier";
    1.27 +
    1.28 +XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
    1.29 +                                   "@mozilla.org/parentprocessmessagemanager;1",
    1.30 +                                   "nsIMessageBroadcaster");
    1.31 +
    1.32 +this.SettingsChangeNotifier = {
    1.33 +  init: function() {
    1.34 +    if (DEBUG) debug("init");
    1.35 +    this.children = [];
    1.36 +    this._messages = ["Settings:Changed", "Settings:RegisterForMessages", "child-process-shutdown"];
    1.37 +    this._messages.forEach((function(msgName) {
    1.38 +      ppmm.addMessageListener(msgName, this);
    1.39 +    }).bind(this));
    1.40 +
    1.41 +    Services.obs.addObserver(this, kXpcomShutdownObserverTopic, false);
    1.42 +    Services.obs.addObserver(this, kMozSettingsChangedObserverTopic, false);
    1.43 +  },
    1.44 +
    1.45 +  observe: function(aSubject, aTopic, aData) {
    1.46 +    if (DEBUG) debug("observe");
    1.47 +    switch (aTopic) {
    1.48 +      case kXpcomShutdownObserverTopic:
    1.49 +        this._messages.forEach((function(msgName) {
    1.50 +          ppmm.removeMessageListener(msgName, this);
    1.51 +        }).bind(this));
    1.52 +        Services.obs.removeObserver(this, kXpcomShutdownObserverTopic);
    1.53 +        Services.obs.removeObserver(this, kMozSettingsChangedObserverTopic);
    1.54 +        ppmm = null;
    1.55 +        break;
    1.56 +      case kMozSettingsChangedObserverTopic:
    1.57 +      {
    1.58 +        let setting = JSON.parse(aData);
    1.59 +        // To avoid redundantly broadcasting settings-changed events that are
    1.60 +        // just requested from content processes themselves, skip the observer
    1.61 +        // messages that are notified from the internal SettingsChangeNotifier.
    1.62 +        if (setting.message && setting.message === kFromSettingsChangeNotifier)
    1.63 +          return;
    1.64 +        this.broadcastMessage("Settings:Change:Return:OK",
    1.65 +          { key: setting.key, value: setting.value });
    1.66 +        break;
    1.67 +      }
    1.68 +      default:
    1.69 +        if (DEBUG) debug("Wrong observer topic: " + aTopic);
    1.70 +        break;
    1.71 +    }
    1.72 +  },
    1.73 +
    1.74 +  broadcastMessage: function broadcastMessage(aMsgName, aContent) {
    1.75 +    if (DEBUG) debug("Broadast");
    1.76 +    this.children.forEach(function(msgMgr) {
    1.77 +      msgMgr.sendAsyncMessage(aMsgName, aContent);
    1.78 +    });
    1.79 +  },
    1.80 +
    1.81 +  receiveMessage: function(aMessage) {
    1.82 +    if (DEBUG) debug("receiveMessage");
    1.83 +    let msg = aMessage.data;
    1.84 +    let mm = aMessage.target;
    1.85 +    switch (aMessage.name) {
    1.86 +      case "Settings:Changed":
    1.87 +        if (!aMessage.target.assertPermission("settings-write")) {
    1.88 +          Cu.reportError("Settings message " + msg.name +
    1.89 +                         " from a content process with no 'settings-write' privileges.");
    1.90 +          return null;
    1.91 +        }
    1.92 +        this.broadcastMessage("Settings:Change:Return:OK",
    1.93 +          { key: msg.key, value: msg.value });
    1.94 +        Services.obs.notifyObservers(this, kMozSettingsChangedObserverTopic,
    1.95 +          JSON.stringify({
    1.96 +            key: msg.key,
    1.97 +            value: msg.value,
    1.98 +            message: kFromSettingsChangeNotifier
    1.99 +          }));
   1.100 +        break;
   1.101 +      case "Settings:RegisterForMessages":
   1.102 +        if (!aMessage.target.assertPermission("settings-read")) {
   1.103 +          Cu.reportError("Settings message " + msg.name +
   1.104 +                         " from a content process with no 'settings-read' privileges.");
   1.105 +          return null;
   1.106 +        }
   1.107 +        if (DEBUG) debug("Register!");
   1.108 +        if (this.children.indexOf(mm) == -1) {
   1.109 +          this.children.push(mm);
   1.110 +        }
   1.111 +        break;
   1.112 +      case "child-process-shutdown":
   1.113 +        if (DEBUG) debug("Unregister");
   1.114 +        let index;
   1.115 +        if ((index = this.children.indexOf(mm)) != -1) {
   1.116 +          if (DEBUG) debug("Unregister index: " + index);
   1.117 +          this.children.splice(index, 1);
   1.118 +        }
   1.119 +        break;
   1.120 +      default:
   1.121 +        if (DEBUG) debug("Wrong message: " + aMessage.name);
   1.122 +    }
   1.123 +  }
   1.124 +}
   1.125 +
   1.126 +SettingsChangeNotifier.init();