Issue 3839 - Adapt for Prefs event changes

background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 (function(global)
 {
+  function EventEmitter()
+  {
+    this._listeners = Object.create(null);
+  }
+  EventEmitter.prototype = {
+    on: function(name, listener)
+    {
+      if (name in this._listeners)
+        this._listeners[name].push(listener);
+      else
+        this._listeners[name] = [listener];
+    },
+    off: function(name, listener)
+    {
+      var listeners = this._listeners[name];
+      if (listeners)
+      {
+        var idx = listeners.indexOf(listener);
+        if (idx != -1)
+          listeners.splice(idx, 1);
+      }
+    },
+    emit: function(name)
+    {
+      var listeners = this._listeners[name];
+      if (listeners)
+      {
+        for (var i = 0; i < listeners.length; i++)
+          listeners[i].apply(null, Array.prototype.slice.call(arguments, 1));
+      }
+    }
+  };
+
   function Notifier()
   {
-    this._listeners = [];
+    this._eventEmitter = new EventEmitter();
   }
   Notifier.prototype = {
-    _listeners: null,
-
     addListener: function(listener)
     {
-      if (this._listeners.indexOf(listener) < 0)
-        this._listeners.push(listener);
+      var listeners = this._eventEmitter[""];

[Thomas Greiner, 2016/03/22 13:29:40]

Detail: Shouldn't this be `var listeners = this._eventEmitter._listeners[""];`?

Functionality-wise there's no difference but it doesn't seem to be done on
purpose.

[Sebastian Noack, 2016/03/22 14:24:10]

Well spotted, and actually it is a bug.

+      if (!listeners || listener.indexOf(listener) == -1)
+        this._eventEmitter.on("", listener);
     },
-
     removeListener: function(listener)
     {
-      var index = this._listeners.indexOf(listener);
-      if (index >= 0)
-        this._listeners.splice(index, 1);
+      this._eventEmitter.off("", listener);
     },
-
     triggerListeners: function()
     {
       var args = Array.prototype.slice.apply(arguments);
-      var listeners = this._listeners.slice();
-      for (var i = 0; i < listeners.length; i++)
-        listeners[i].apply(null, args);
+      args.unshift("");
+      this._eventEmitter.emit.apply(this._eventEmitter, args);
     }
   };
 
   function updateFromURL(data)
   {
     if (window.location.search)
     {
       var params = window.location.search.substr(1).split("&");
       for (var i = 0; i < params.length; i++)
       {
@@ skipping 28 matching lines @@
       {
         return "https://adblockplus.org/redirect?link=" + encodeURIComponent(link);
       },
       get appLocale()
       {
         return parent.ext.i18n.getMessage("@@ui_locale").replace(/_/g, "-");
       }
     }
   };
 
-  modules.prefs = {
-    Prefs: {
-      onChanged: new Notifier()
-    }
-  };
+  modules.prefs = {Prefs: new EventEmitter()};
   var prefs = {
     notifications_ignoredcategories: (params.showNotificationUI) ? ["*"] : [],
     notifications_showui: params.showNotificationUI,
     safari_contentblocker: false,
     shouldShowBlockElementMenu: true,
     show_devtools_panel: true,
     subscriptions_exceptionsurl: "https://easylist-downloads.adblockplus.org/exceptionrules.txt"
   };
   Object.keys(prefs).forEach(function(key)
   {
     Object.defineProperty(modules.prefs.Prefs, key, {
       get: function()
       {
         return prefs[key];
       },
       set: function(value)
       {
         prefs[key] = value;
-        modules.prefs.Prefs.onChanged.triggerListeners(key);
-        return prefs[key];
+        modules.prefs.Prefs.emit(key);
       }
     });
   });
 
   modules.notification = {
     Notification: {
       toggleIgnoreCategory: function(category)
       {
         var categories = prefs.notifications_ignoredcategories;
         var index = categories.indexOf(category);
@@ skipping 341 matching lines @@
 
   if (params.safariContentBlocker)
   {
     global.safari = {
       extension: {
         setContentBlocker: function() {}
       }
     };
   }
 })(this);