Issue 3839 - Adapt for Prefs event changes

messageResponder.js

Index: messageResponder.js
===================================================================
--- a/messageResponder.js
+++ b/messageResponder.js
@@ -60,13 +60,14 @@
     "subscription": "subscriptions.listen"
   };
 
-  function sendMessage(type, action, args, page)
+  function sendMessage(type, action, args)
   {
-    var pages = page ? [page] : changeListeners.keys();
+    var pages = changeListeners.keys();

[Sebastian Noack, 2016/03/19 19:17:29]

This is unrelated, but since page is never specified, I used the chance to get
rid of the dead code here.

     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 instanceof Array && actions.indexOf(action) == -1))

[Sebastian Noack, 2016/03/19 19:17:29]

filters.pref is an object now, not an array anymore. And filtering is done by
Prefs.on, so it can/must be skipped here.

       {
         pages[i].sendMessage({
           type:  messageTypes[type],
@@ -110,11 +111,6 @@
     sendMessage(type, action, args);
   }
 
-  function onPrefChange(name)
-  {
-    sendMessage("pref", name, [Prefs[name]]);
-  }
-
   global.ext.onMessage.addListener(function(message, sender, callback)
   {
     var listenerFilters = null;
@@ -124,7 +120,6 @@
       {
         changeListeners = new global.ext.PageMap();
         FilterNotifier.addListener(onFilterChange);
-        Prefs.onChanged.addListener(onPrefChange);
       }
 
       listenerFilters = changeListeners.get(sender.page);
@@ -307,8 +302,23 @@
         callback(Prefs[message.key]);
         break;
       case "prefs.listen":
+        for (var preference in listenerFilters.pref)
+          Prefs.off(preference, listenerFilters.pref[preference]);
+
         if (message.filter)
-          listenerFilters.pref = message.filter;
+        {
+          listenerFilters.pref = Object.create(null);
+          message.filter.forEach(function(preference)
+          {
+            function callback()
+            {
+              sendMessage("prefs", preference, [Prefs[preference]]);
+            }
+
+            listenerFilters.pref[preference] = callback;
+            Prefs.on(preference, callback);
+          });
+        }
         else
           delete listenerFilters.pref;
         break;