Issue 3839 - Adapt for Prefs event changes

messageResponder.js

Index: messageResponder.js
===================================================================
--- a/messageResponder.js
+++ b/messageResponder.js
@@ -52,7 +52,9 @@
     "downloadStatus", "homepage", "lastDownload", "title", "url"]);
   var convertFilter = convertObject.bind(null, ["text"]);
 
-  var changeListeners = null;
+  var changeListeners = new global.ext.PageMap();
+  var filterListenerAdded = false;
+  var listenedPreferences = [];
   var messageTypes = {
     "app": "app.listen",
     "filter": "filters.listen",
@@ -60,13 +62,14 @@
     "subscription": "subscriptions.listen"
   };
 
-  function sendMessage(type, action, args, page)
+  function sendMessage(type, action, args)
   {
-    var pages = page ? [page] : changeListeners.keys();
+    var pages = changeListeners.keys();
     for (var i = 0; i < pages.length; i++)
     {
       var filters = changeListeners.get(pages[i]);
-      if (filters[type] && filters[type].indexOf(action) >= 0)
+      var actions = filters[type];
+      if (actions && actions.indexOf(action) != -1)
       {
         pages[i].sendMessage({
           type:  messageTypes[type],
@@ -110,31 +113,26 @@
     sendMessage(type, action, args);
   }
 
-  function onPrefChange(name)
+  function getListenerFilters(page, addListener)
   {
-    sendMessage("pref", name, [Prefs[name]]);
+    if (addListener && !filterListenerAdded)
+    {
+      FilterNotifier.addListener(onFilterChange);
+      filterListenerAdded = true;
+    }
+
+    var listenerFilters = changeListeners.get(page);
+    if (!listenerFilters)
+    {
+      listenerFilters = Object.create(null);
+      changeListeners.set(page, listenerFilters);
+    }
+
+    return listenerFilters;
   }
 
   global.ext.onMessage.addListener(function(message, sender, callback)
   {
-    var listenerFilters = null;
-    if (/\.listen$/.test(message.type))
-    {
-      if (!changeListeners)
-      {
-        changeListeners = new global.ext.PageMap();
-        FilterNotifier.addListener(onFilterChange);
-        Prefs.onChanged.addListener(onPrefChange);
-      }
-
-      listenerFilters = changeListeners.get(sender.page);
-      if (!listenerFilters)
-      {
-        listenerFilters = Object.create(null);
-        changeListeners.set(sender.page, listenerFilters);
-      }
-    }
-
     switch (message.type)
     {
       case "app.get":
@@ -187,6 +185,7 @@
           callback(null);
         break;
       case "app.listen":
+        var listenerFilters = getListenerFilters(sender.page, false);
         if (message.filter)
           listenerFilters.app = message.filter;
         else
@@ -287,6 +286,7 @@
         }
         break;
       case "filters.listen":
+        var listenerFilters = getListenerFilters(sender.page, true);
         if (message.filter)
           listenerFilters.filter = message.filter;
         else
@@ -307,8 +307,22 @@
         callback(Prefs[message.key]);
         break;
       case "prefs.listen":
+        var listenerFilters = getListenerFilters(sender.page, false);
         if (message.filter)
+        {
+          message.filter.forEach(function(preference)
+          {
+            if (listenedPreferences.indexOf(preference) == -1)
+            {
+              listenedPreferences.push(preference);
+              Prefs.on(preference, function()
+              {
+                sendMessage("pref", preference, [Prefs[preference]]);
+              });
+            }
+          });
           listenerFilters.pref = message.filter;
+        }
         else
           delete listenerFilters.pref;
         break;
@@ -355,6 +369,7 @@
         callback(subscriptions.map(convertSubscription));
         break;
       case "subscriptions.listen":
+        var listenerFilters = getListenerFilters(sender.page, true);
         if (message.filter)
           listenerFilters.subscription = message.filter;
         else