Functional prefs implementation

lib/init.js

-require("filterNotifier").FilterNotifier.addListener(function(action)
+let {Prefs} = require("prefs");
+let {FilterNotifier} = require("filterNotifier");
+
+let prefsInitDone = false;
+let filtersInitDone = false;
+
+function checkInitialized()
+{
+  if (prefsInitDone && filtersInitDone)
+  {
+    checkInitialized = function() {};
+    _triggerEvent("init");
+  }
+}
+
+Prefs._initListener = function()
+{
+  prefsInitDone = true;
+  checkInitialized();
+};
+
+FilterNotifier.addListener(function(action)
 {
   if (action === "load")
   {
     let {FilterStorage} = require("filterStorage");
     if (FilterStorage.subscriptions.length == 0)
     {
       // No data, must be a new user or someone with corrupted data - initialize
       // with default settings
       let {Subscription, DownloadableSubscription} = require("subscriptionClasses");
       let {Synchronizer} = require("synchronizer");
       let {Prefs} = require("prefs");
       let {Utils} = require("utils");
 
       // Choose default subscription and add it
       let subscriptions = require("subscriptions.xml");
       let node = Utils.chooseFilterSubscription(subscriptions);
       if (node)
       {
         let subscription = Subscription.fromURL(node.url);
         FilterStorage.addSubscription(subscription);
         subscription.disabled = false;
         subscription.title = node.title;
         subscription.homepage = node.homepage;
         if (subscription instanceof DownloadableSubscription && !subscription.lastDownload)
           Synchronizer.execute(subscription);
       }
     }
 
-    _triggerEvent("init");
+    filtersInitDone = true;
+    checkInitialized();
   }
 });