Issue 3870 - Rewrite legacy options page to use async messages

options.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/>.
  */
 
-var backgroundPage = ext.backgroundPage.getWindow();
-var require = backgroundPage.require;
+"use strict";
 
-with(require("filterClasses"))
+/**
+ * Creates a wrapping function used to conveniently send a type of message.
+ *
+ * @param {Object} baseMessage The part of the message that's always sent
+ * @param {..string} paramKeys Any message keys that have dynamic values. The
+ *                             returned function will take the corresponding
+ *                             values as arguments.
+ * @return The generated messaging function, optionally taking any values as
+ *         specified by the paramKeys and finally an optional callback.
+ *         (Although the value arguments are optional their index must be
+ *          maintained. E.g. if you omit the first value you must omit the
+ *          second too.)
+ */
+function wrapper(baseMessage /* , [paramKeys] */)
 {
-  this.Filter = Filter;
-  this.WhitelistFilter = WhitelistFilter;
+  var paramKeys = [];
+  for (var i = 1; i < arguments.length; i++)
+    paramKeys.push(arguments[i]);
+
+  return function(/* [paramValues], callback */)
+  {
+    var message = Object.create(null);
+    for (var key in baseMessage)
+      if (baseMessage.hasOwnProperty(key))
+        message[key] = baseMessage[key];
+
+    var paramValues = [];
+    var callback;
+
+    if (arguments.length > 0)
+    {
+      var lastArg = arguments[arguments.length - 1];
+      if (typeof lastArg == "function")
+        callback = lastArg;
+
+      for (var i = 0; i < arguments.length - (callback ? 1 : 0); i++)
+        message[paramKeys[i]] = arguments[i];
+    }
+
+    ext.backgroundPage.sendMessage(message, callback);
+  };
 }
-with(require("subscriptionClasses"))
-{
-  this.Subscription = Subscription;
-  this.SpecialSubscription = SpecialSubscription;
-  this.DownloadableSubscription = DownloadableSubscription;
-}
-with(require("filterValidation"))
-{
-  this.parseFilter = parseFilter;
-  this.parseFilters = parseFilters;
-}
-var FilterStorage = require("filterStorage").FilterStorage;
-var FilterNotifier = require("filterNotifier").FilterNotifier;
-var Prefs = require("prefs").Prefs;
-var Synchronizer = require("synchronizer").Synchronizer;
-var Utils = require("utils").Utils;
-var NotificationStorage = require("notification").Notification;
-var info = require("info");
 
-// Loads options from localStorage and sets UI elements accordingly
+var getDocLink = wrapper({type: "app.get", what: "doclink"}, "link");
+var getInfo = wrapper({type: "app.get"}, "what");
+var getPref = wrapper({type: "prefs.get"}, "key");
+var togglePref = wrapper({type: "prefs.toggle"}, "key");
+var getSubscriptions = wrapper({type: "subscriptions.get"},
+                               "downloadable", "special");
+var removeSubscription = wrapper({type: "subscriptions.remove"}, "url");
+var addSubscription = wrapper({type: "subscriptions.add"},
+                                "url", "title", "homepage");
+var toggleSubscription = wrapper({type: "subscriptions.toggle"},
+                                 "url", "keepInstalled");
+var updateSubscription = wrapper({type: "subscriptions.update"}, "url");
+var importRawFilters = wrapper({type: "filters.importRaw"},
+                               "text", "removeExisting");
+var addFilter = wrapper({type: "filters.add"}, "text");
+var getFilters = wrapper({type: "filters.get"}, "subscriptionUrl");
+var removeFilter = wrapper({type: "filters.remove"}, "text");
+
+var i18n = ext.i18n;
+var whitelistedDomainRegexp = /^@@\|\|([^\/:]+)\^\$document$/;
+var delayedSubscriptionSelection = null;
+
+// Loads options and sets UI elements accordingly
 function loadOptions()
 {
   // Set page title to i18n version of "Adblock Plus Options"
   document.title = i18n.getMessage("options");
 
   // Set links
-  $("#acceptableAdsLink").attr("href", Prefs.subscriptions_exceptionsurl);
-  $("#acceptableAdsDocs").attr("href", Utils.getDocLink("acceptable_ads"));
-  setLinks("filter-must-follow-syntax", Utils.getDocLink("filterdoc"));
-  setLinks("found-a-bug", Utils.getDocLink(info.application + "_support"));
+  getPref("subscriptions_exceptionsurl", function(url)
+  {
+    $("#acceptableAdsLink").attr("href", url);
+  });
+  getDocLink("acceptable_ads", function(url)
+  {
+    $("#acceptableAdsDocs").attr("href", url);
+  });
+  getDocLink("filterdoc", function(url)
+  {
+    setLinks("filter-must-follow-syntax", url);
+  });
+  getInfo("application", function(application)
+  {
+    getInfo("platform", function(platform)
+    {
+      if (platform == "chromium" && application != "opera")
+        application = "chrome";
+
+      getDocLink(application + "_support", function(url)
+      {
+        setLinks("found-a-bug", url);
+      });
+    });
+  });
 
   // Add event listeners
-  window.addEventListener("unload", unloadOptions, false);
   $("#updateFilterLists").click(updateFilterLists);
   $("#startSubscriptionSelection").click(startSubscriptionSelection);
   $("#subscriptionSelector").change(updateSubscriptionSelection);
-  $("#addSubscription").click(addSubscription);
-  $("#acceptableAds").click(allowAcceptableAds);
+  $("#addSubscription").click(addSubscriptionClicked);
+  $("#acceptableAds").click(toggleAcceptableAds);
   $("#whitelistForm").submit(addWhitelistDomain);
   $("#removeWhitelist").click(removeSelectedExcludedDomain);
   $("#customFilterForm").submit(addTypedFilter);
   $("#removeCustomFilter").click(removeSelectedFilters);
   $("#rawFiltersButton").click(toggleFiltersInRawFormat);
   $("#importRawFilters").click(importRawFiltersText);
 
-  FilterNotifier.on("load", reloadFilters);
-  FilterNotifier.on("subscription.title", onSubscriptionChange);
-  FilterNotifier.on("subscription.disabled", onSubscriptionChange);
-  FilterNotifier.on("subscription.homepage", onSubscriptionChange);
-  FilterNotifier.on("subscription.lastDownload", onSubscriptionChange);
-  FilterNotifier.on("subscription.downloadStatus", onSubscriptionChange);
-  FilterNotifier.on("subscription.added", onSubscriptionAdded);
-  FilterNotifier.on("subscription.removed", onSubscriptionRemoved);
-  FilterNotifier.on("filter.added", onFilterAdded);
-  FilterNotifier.on("filter.removed", onFilterRemoved);
-
   // Display jQuery UI elements
   $("#tabs").tabs();
   $("button").button();
   $(".refreshButton").button("option", "icons", {primary: "ui-icon-refresh"});
   $(".addButton").button("option", "icons", {primary: "ui-icon-plus"});
   $(".removeButton").button("option", "icons", {primary: "ui-icon-minus"});
 
   // Popuplate option checkboxes
   initCheckbox("shouldShowBlockElementMenu");
   initCheckbox("show_devtools_panel");
   initCheckbox("shouldShowNotifications", {
-    get: function()
+    key: "notifications_ignoredcategories",
+    get: function(ignoredcategories)
     {
-      return Prefs.notifications_ignoredcategories.indexOf("*") == -1;
-    },
-    toggle: function()
-    {
-      NotificationStorage.toggleIgnoreCategory("*");
-      return this.get();
+      return ignoredcategories.indexOf("*") == -1;
     }
   });
 
-  if (info.platform != "chromium")
-    document.getElementById("showDevtoolsPanelContainer").hidden = true;
-  if (!Prefs.notifications_showui)
-    document.getElementById("shouldShowNotificationsContainer").hidden = true;
+  getInfo("features", function(features)
+  {
+    if (!features.devToolsPanel)
+      document.getElementById("showDevtoolsPanelContainer").hidden = true;
+  });
+  getPref("notifications_showui", function(notifications_showui)
+  {
+    if (!notifications_showui)
+      document.getElementById("shouldShowNotificationsContainer").hidden = true;
+  });
 
-  ext.onMessage.addListener(onMessage);
+  // Register listeners in the background message responder
   ext.backgroundPage.sendMessage({
     type: "app.listen",
-    filter: ["addSubscription"]
+    filter: ["addSubscription", "focusSection"]
+  });
+  ext.backgroundPage.sendMessage(
+  {
+    type: "filters.listen",
+    filter: ["added", "loaded", "removed"]
+  });
+  ext.backgroundPage.sendMessage(
+  {
+    type: "prefs.listen",
+    filter: ["notifications_ignoredcategories", "notifications_showui",
+             "safari_contentblocker", "show_devtools_panel",
+             "shouldShowBlockElementMenu"]
+  });
+  ext.backgroundPage.sendMessage(
+  {
+    type: "subscriptions.listen",
+    filter: ["added", "disabled", "homepage", "lastDownload", "removed",
+             "title", "downloadStatus", "downloading"]
   });
 
   // Load recommended subscriptions
   loadRecommendations();
 
   // Show user's filters
   reloadFilters();
 }
 $(loadOptions);
 
-function onMessage(msg)
-{
-  if (msg.type == "app.listen")
-  {
-    if (msg.action == "addSubscription")
-    {
-      var subscription = msg.args[0];
-      startSubscriptionSelection(subscription.title, subscription.url);
-    }
-  }
-  else if (msg.type == "focus-section")
-  {
-    var tabs = document.getElementsByClassName("ui-tabs-panel");
-    for (var i = 0; i < tabs.length; i++)
-    {
-      var found = tabs[i].querySelector("[data-section='" + msg.section + "']");
-      if (!found)
-        continue;
-
-      var previous = document.getElementsByClassName("focused");
-      if (previous.length > 0)
-        previous[0].classList.remove("focused");
-
-      var tab = $("[href='#" + tabs[i].id + "']");
-      $("#tabs").tabs("select", tab.parent().index());
-      found.classList.add("focused");
-    }
-  }
-};
-
 // Reloads the displayed subscriptions and filters
 function reloadFilters()
 {
   // Load user filter URLs
   var container = document.getElementById("filterLists");
   while (container.lastChild)
     container.removeChild(container.lastChild);
 
-  var hasAcceptable = false;
-  for (var i = 0; i < FilterStorage.subscriptions.length; i++)
+  getPref("subscriptions_exceptionsurl", function(acceptableAdsUrl)
   {
-    var subscription = FilterStorage.subscriptions[i];
-    if (subscription instanceof SpecialSubscription)
-      continue;
-
-    if (subscription.url == Prefs.subscriptions_exceptionsurl)
+    getSubscriptions(true, false, function(subscriptions)
     {
-      hasAcceptable = true;
-      continue;
-    }
-
-    addSubscriptionEntry(subscription);
-  }
-
-  $("#acceptableAds").prop("checked", hasAcceptable);
+      for (var i = 0; i < subscriptions.length; i++)
+      {
+        var subscription = subscriptions[i];
+        if (subscription.url == acceptableAdsUrl)
+          $("#acceptableAds").prop("checked", !subscription.disabled);
+        else
+          addSubscriptionEntry(subscription);
+      }
+    });
+  });
 
   // User-entered filters
-  var userFilters = backgroundPage.getUserFilters();
-  populateList("userFiltersBox", userFilters.filters);
-  populateList("excludedDomainsBox", userFilters.exceptions);
-}
+  getSubscriptions(false, true, function(subscriptions)
+  {
+    clearListBox("userFiltersBox");
+    clearListBox("excludedDomainsBox");
 
-// Cleans up when the options window is closed
-function unloadOptions()
-{
-  FilterNotifier.off("load", reloadFilters);
-  FilterNotifier.off("subscription.title", onSubscriptionChange);
-  FilterNotifier.off("subscription.disabled", onSubscriptionChange);
-  FilterNotifier.off("subscription.homepage", onSubscriptionChange);
-  FilterNotifier.off("subscription.lastDownload", onSubscriptionChange);
-  FilterNotifier.off("subscription.downloadStatus", onSubscriptionChange);
-  FilterNotifier.off("subscription.added", onSubscriptionAdded);
-  FilterNotifier.off("subscription.removed", onSubscriptionRemoved);
-  FilterNotifier.off("filter.added", onFilterAdded);
-  FilterNotifier.off("filter.removed", onFilterRemoved);
+    for (var i = 0; i < subscriptions.length; i++)
+      getFilters(subscriptions[i].url, function(filters)
+      {
+        for (var j = 0; j < filters.length; j++)
+        {
+          var filter = filters[j].text;
+          if (whitelistedDomainRegexp.test(filter))
+            appendToListBox("excludedDomainsBox", RegExp.$1);
+          else
+            appendToListBox("userFiltersBox", filter);
+        }
+      });
+  });
 }
 
 function initCheckbox(id, descriptor)
 {
   var checkbox = document.getElementById(id);
-  if (descriptor && descriptor.get)
-    checkbox.checked = descriptor.get();
-  else
-    checkbox.checked = Prefs[id];
+  var key = descriptor && descriptor.key || id;
+  getPref(key, function(value)
+  {
+    if (descriptor && descriptor.get)
+      checkbox.checked = descriptor.get(value);
+    else
+      checkbox.checked = value;
+  });
 
   checkbox.addEventListener("click", function()
   {
     if (descriptor && descriptor.toggle)
       checkbox.checked = descriptor.toggle();
-
-    Prefs[id] = checkbox.checked;
+    togglePref(key);
   }, false);
 }
 
-var delayedSubscriptionSelection = null;
-
 function loadRecommendations()
 {
   fetch("subscriptions.xml")
     .then(function(response)
     {
       return response.text();
     })
     .then(function(text)
     {
       var selectedIndex = 0;
       var selectedPrefix = null;
       var matchCount = 0;
 
       var list = document.getElementById("subscriptionSelector");
       var doc = new DOMParser().parseFromString(text, "application/xml");
       var elements = doc.documentElement.getElementsByTagName("subscription");
 
       for (var i = 0; i < elements.length; i++)
       {
         var element = elements[i];
         var option = new Option();
         option.text = element.getAttribute("title") + " (" +
                       element.getAttribute("specialization") + ")";
         option._data = {
           title: element.getAttribute("title"),
           url: element.getAttribute("url"),
           homepage: element.getAttribute("homepage")
         };
 
-        var prefixes = element.getAttribute("prefixes");
-        var prefix = Utils.checkLocalePrefixMatch(prefixes);
+        var prefix = element.getAttribute("prefixes");
         if (prefix)
         {
+          prefix = prefix.replace(/\W/g, "_");
           option.style.fontWeight = "bold";
           option.style.backgroundColor = "#E0FFE0";
           option.style.color = "#000000";
           if (!selectedPrefix || selectedPrefix.length < prefix.length)
           {
             selectedIndex = i;
             selectedPrefix = prefix;
             matchCount = 1;
           }
           else if (selectedPrefix && selectedPrefix.length == prefix.length)
@@ skipping 56 matching lines @@
   var data = list.options[list.selectedIndex]._data;
   if (data)
     $("#customSubscriptionContainer").hide();
   else
   {
     $("#customSubscriptionContainer").show();
     $("#customSubscriptionTitle").focus();
   }
 }
 
-function addSubscription()
+function addSubscriptionClicked()
 {
   var list = document.getElementById("subscriptionSelector");
   var data = list.options[list.selectedIndex]._data;
   if (data)
-    doAddSubscription(data.url, data.title, data.homepage);
+    addSubscription(data.url, data.title, data.homepage);
   else
   {
     var url = document.getElementById("customSubscriptionLocation").value.trim();
     if (!/^https?:/i.test(url))
     {
       alert(i18n.getMessage("global_subscription_invalid_location"));
       $("#customSubscriptionLocation").focus();
       return;
     }
 
     var title = document.getElementById("customSubscriptionTitle").value.trim();
     if (!title)
       title = url;
 
-    doAddSubscription(url, title, null);
+    addSubscription(url, title, null);
   }
 
   $("#addSubscriptionContainer").hide();
   $("#customSubscriptionContainer").hide();
   $("#addSubscriptionButton").show();
 }
 
-function doAddSubscription(url, title, homepage)
+function toggleAcceptableAds()
 {
-  if (url in FilterStorage.knownSubscriptions)
-    return;
-
-  var subscription = Subscription.fromURL(url);
-  if (!subscription)
-    return;
-
-  subscription.title = title;
-  if (homepage)
-    subscription.homepage = homepage;
-  FilterStorage.addSubscription(subscription);
-
-  if (subscription instanceof DownloadableSubscription && !subscription.lastDownload)
-    Synchronizer.execute(subscription);
-}
-
-function allowAcceptableAds(event)
-{
-  var subscription = Subscription.fromURL(Prefs.subscriptions_exceptionsurl);
-  if (!subscription)
-    return;
-
-  subscription.disabled = false;
-  subscription.title = "Allow non-intrusive advertising";
-  if ($("#acceptableAds").prop("checked"))
+  getPref("subscriptions_exceptionsurl", function(url)
   {
-    FilterStorage.addSubscription(subscription);
-    if (subscription instanceof DownloadableSubscription && !subscription.lastDownload)
-      Synchronizer.execute(subscription);
-  }
-  else
-    FilterStorage.removeSubscription(subscription);
+    toggleSubscription(url, true);
+  });
 }
 
 function findSubscriptionElement(subscription)
 {
   var children = document.getElementById("filterLists").childNodes;
   for (var i = 0; i < children.length; i++)
-    if (children[i]._subscription == subscription)
+    if (children[i]._subscription.url == subscription.url)
       return children[i];
   return null;
 }
 
-function updateSubscriptionInfo(element)
+function updateSubscriptionInfo(element, subscription)
 {
-  var subscription = element._subscription;
+  if (subscription)
+    element._subscription = subscription;
+  else
+    subscription = element._subscription;
 
   var title = element.getElementsByClassName("subscriptionTitle")[0];
   title.textContent = subscription.title;
   title.setAttribute("title", subscription.url);
   if (subscription.homepage)
     title.href = subscription.homepage;
   else
     title.href = subscription.url;
 
   var enabled = element.getElementsByClassName("subscriptionEnabled")[0];
   enabled.checked = !subscription.disabled;
 
   var lastUpdate = element.getElementsByClassName("subscriptionUpdate")[0];
   lastUpdate.classList.remove("error");
-  if (Synchronizer.isExecuting(subscription.url))
+
+  var downloadStatus = subscription.downloadStatus;
+  if (subscription.isDownloading)
+  {
     lastUpdate.textContent = i18n.getMessage("filters_subscription_lastDownload_inProgress");
-  else if (subscription.downloadStatus && subscription.downloadStatus != "synchronize_ok")
+  }
+  else if (downloadStatus && downloadStatus != "synchronize_ok")
   {
-    var map =
-    {
-      "synchronize_invalid_url": "filters_subscription_lastDownload_invalidURL",
-      "synchronize_connection_error": "filters_subscription_lastDownload_connectionError",
-      "synchronize_invalid_data": "filters_subscription_lastDownload_invalidData",
-      "synchronize_checksum_mismatch": "filters_subscription_lastDownload_checksumMismatch"
-    };
-    if (subscription.downloadStatus in map)
-      lastUpdate.textContent = i18n.getMessage(map[subscription.downloadStatus]);
-    else
-      lastUpdate.textContent = subscription.downloadStatus;
-    lastUpdate.classList.add("error");
+     var map =
+     {
+       "synchronize_invalid_url": "filters_subscription_lastDownload_invalidURL",
+       "synchronize_connection_error": "filters_subscription_lastDownload_connectionError",
+       "synchronize_invalid_data": "filters_subscription_lastDownload_invalidData",
+       "synchronize_checksum_mismatch": "filters_subscription_lastDownload_checksumMismatch"
+     };
+     if (downloadStatus in map)
+       lastUpdate.textContent = i18n.getMessage(map[downloadStatus]);
+     else
+       lastUpdate.textContent = downloadStatus;
+     lastUpdate.classList.add("error");
   }
   else if (subscription.lastDownload > 0)
   {
     var timeDate = i18n_timeDateStrings(subscription.lastDownload * 1000);
     var messageID = (timeDate[1] ? "last_updated_at" : "last_updated_at_today");
     lastUpdate.textContent = i18n.getMessage(messageID, timeDate);
   }
 }
 
-function onSubscriptionChange(subscription)
+function onSubscriptionMessage(action, subscription)
 {
   var element = findSubscriptionElement(subscription);
-  if (element)
-    updateSubscriptionInfo(element);
-}
 
-function onSubscriptionAdded(subscription)
-{
-  if (subscription instanceof SpecialSubscription)
+  switch (action)
   {
-    for (var i = 0; i < subscription.filters.length; i++)
-      onFilterAdded(subscription.filters[i]);
-  }
-  else if (subscription.url == Prefs.subscriptions_exceptionsurl)
-    $("#acceptableAds").prop("checked", true);
-  else if (!findSubscriptionElement(subscription))
-    addSubscriptionEntry(subscription);
-}
+    case "disabled":
+    case "downloading":
+    case "downloadStatus":
+    case "homepage":
+    case "lastDownload":
+    case "title":
+      if (element)
+        updateSubscriptionInfo(element, subscription);
+      break;
+    case "added":
+      getPref("subscriptions_exceptionsurl", function(acceptableAdsUrl)
+      {
+        // Hack - Assume newly added subscriptions are currently downloading as
+        //        we process the downloading message before we have finished
+        //        adding the subscription's element!
+        subscription.isDownloading = true;

[Sebastian Noack, 2016/04/07 12:49:14]

That is because you asynchronously retrieve the Acceptable Ads URL. However,
while you wait for a response, the "downloading" notification already arrives.
Note that theoretically, other subscription changes might occur meanwhile as
well, causing similar issues.

How about simply retrieving the Acceptable Ads URL once as very first thing you
do when the options page loads, and caching it in a global variable? That would
not only make this hack redundant, but also reduces the total amount of messages
sent and simplifies the code a bit.

[kzar, 2016/04/07 13:04:53]

Much better solution and works fine. Done.

 
-function onSubscriptionRemoved(subscription)
-{
-  if (subscription instanceof SpecialSubscription)
-  {
-    for (var i = 0; i < subscription.filters.length; i++)
-      onFilterRemoved(subscription.filters[i]);
-  }
-  else if (subscription.url == Prefs.subscriptions_exceptionsurl)
-    $("#acceptableAds").prop("checked", false);
-  else
-  {
-    var element = findSubscriptionElement(subscription);
-    if (element)
-      element.parentNode.removeChild(element);
+        if (subscription.url == acceptableAdsUrl)
+          $("#acceptableAds").prop("checked", true);
+        else if (!element)
+          addSubscriptionEntry(subscription);
+      });
+      break;
+    case "removed":
+      getPref("subscriptions_exceptionsurl", function(acceptableAdsUrl)
+      {
+        if (subscription.url == acceptableAdsUrl)
+          $("#acceptableAds").prop("checked", false);
+        else if (element)
+          element.parentNode.removeChild(element);
+      });
+      break;
   }
 }
 
-function onFilterAdded(filter)
+function onPrefMessage(key, value)
 {
-  if (filter instanceof WhitelistFilter &&
-      /^@@\|\|([^\/:]+)\^\$document$/.test(filter.text))
-    appendToListBox("excludedDomainsBox", RegExp.$1);
-  else
-    appendToListBox("userFiltersBox", filter.text);
+  switch (key)
+  {
+    case "notifications_showui":
+      document.getElementById("shouldShowNotificationsContainer").hidden = !value;
+      return;
+    case "notifications_ignoredcategories":
+      key = "shouldShowNotifications";
+      value = value.indexOf("*") == -1;
+      break;
+  }
+
+  var checkbox = document.getElementById(key);
+  if (checkbox)
+    checkbox.checked = value;
 }
 
-function onFilterRemoved(filter)
+function onFilterMessage(action, filter)
 {
-  if (filter instanceof WhitelistFilter &&
-      /^@@\|\|([^\/:]+)\^\$document$/.test(filter.text))
-    removeFromListBox("excludedDomainsBox", RegExp.$1);
-  else
-    removeFromListBox("userFiltersBox", filter.text);
+  switch (action)
+  {
+    case "loaded":
+      reloadFilters();
+      break;
+    case "added":
+      if (whitelistedDomainRegexp.test(filter.text))
+        appendToListBox("excludedDomainsBox", RegExp.$1);
+      else
+        appendToListBox("userFiltersBox", filter.text);
+      break;
+    case "removed":
+      if (whitelistedDomainRegexp.test(filter.text))
+        removeFromListBox("excludedDomainsBox", RegExp.$1);
+      else
+        removeFromListBox("userFiltersBox", filter.text);
+      break;
+  }
 }
 
-// Populates a list box with a number of entries
-function populateList(id, entries)
+function clearListBox(id)
 {
   var list = document.getElementById(id);
   while (list.lastChild)
     list.removeChild(list.lastChild);
-
-  entries.sort();
-  for (var i = 0; i < entries.length; i++)
-  {
-    var option = new Option();
-    option.text = entries[i];
-    option.value = entries[i];
-    list.appendChild(option);
-  }
 }
 
 // Add a filter string to the list box.
 function appendToListBox(boxId, text)
 {
-  var elt = new Option();  /* Note: document.createElement("option") is unreliable in Opera */
+  // Note: document.createElement("option") is unreliable in Opera
+  var elt = new Option();
   elt.text = text;
   elt.value = text;
   document.getElementById(boxId).appendChild(elt);
 }
 
 // Remove a filter string from a list box.
 function removeFromListBox(boxId, text)
 {
   var list = document.getElementById(boxId);
   for (var i = 0; i < list.length; i++)
     if (list.options[i].value == text)
       list.remove(i--);
 }
 
 function addWhitelistDomain(event)
 {
   event.preventDefault();
 
   var domain = document.getElementById("newWhitelistDomain").value.replace(/\s/g, "");
   document.getElementById("newWhitelistDomain").value = "";
   if (!domain)
     return;
 
   var filterText = "@@||" + domain + "^$document";
-  FilterStorage.addFilter(Filter.fromText(filterText));
+  addFilter(filterText);
 }
 
 // Adds filter text that user typed to the selection box
 function addTypedFilter(event)
 {
   event.preventDefault();
 
   var element = document.getElementById("newFilter");
-  var result = parseFilter(element.value);
-
-  if (result.error)
+  addFilter(element.value, function(errors)
   {
-    alert(result.error);
-    return;
-  }
-
-  if (result.filter)
-    FilterStorage.addFilter(result.filter);
-
-  element.value = "";
+    if (errors.length > 0)
+      alert(errors.join("\n"));
+    else
+      element.value = "";
+  });
 }
 
 // Removes currently selected whitelisted domains
 function removeSelectedExcludedDomain(event)
 {
   event.preventDefault();
   var excludedDomainsBox = document.getElementById("excludedDomainsBox");
   var remove = [];
   for (var i = 0; i < excludedDomainsBox.length; i++)
     if (excludedDomainsBox.options[i].selected)
       remove.push(excludedDomainsBox.options[i].value);
   if (!remove.length)
     return;
 
   for (var i = 0; i < remove.length; i++)
-    FilterStorage.removeFilter(Filter.fromText("@@||" + remove[i] + "^$document"));
+    removeFilter("@@||" + remove[i] + "^$document");
 }
 
 // Removes all currently selected filters
 function removeSelectedFilters(event)
 {
   event.preventDefault();
   var userFiltersBox = document.getElementById("userFiltersBox");
   var remove = [];
   for (var i = 0; i < userFiltersBox.length; i++)
     if (userFiltersBox.options[i].selected)
       remove.push(userFiltersBox.options[i].value);
   if (!remove.length)
     return;
 
   for (var i = 0; i < remove.length; i++)
-    FilterStorage.removeFilter(Filter.fromText(remove[i]));
+    removeFilter(remove[i]);
 }
 
 // Shows raw filters box and fills it with the current user filters
 function toggleFiltersInRawFormat(event)
 {
   event.preventDefault();
 
   $("#rawFilters").toggle();
   if ($("#rawFilters").is(":visible"))
   {
     var userFiltersBox = document.getElementById("userFiltersBox");
     var text = "";
     for (var i = 0; i < userFiltersBox.length; i++)
       text += userFiltersBox.options[i].value + "\n";
     document.getElementById("rawFiltersText").value = text;
   }
 }
 
 // Imports filters in the raw text box
 function importRawFiltersText()
 {
   var text = document.getElementById("rawFiltersText").value;
-  var result = parseFilters(text);
 
-  var errors = result.errors.filter(function(e)
+  importRawFilters(text, true, function(errors)
   {
-    return e.type != "unexpected-filter-list-header";
+    if (errors.length > 0)
+      alert(errors.join("\n"));
+    else
+      $("#rawFilters").hide();
   });
-
-  if (errors.length > 0)
-  {
-    alert(errors.join("\n"));
-    return;
-  }
-
-  var seenFilter = Object.create(null);
-  for (var i = 0; i < result.filters.length; i++)
-  {
-    var filter = result.filters[i];
-    FilterStorage.addFilter(filter);
-    seenFilter[filter.text] = null;
-  }
-
-  var remove = [];
-  for (var i = 0; i < FilterStorage.subscriptions.length; i++)
-  {
-    var subscription = FilterStorage.subscriptions[i];
-    if (!(subscription instanceof SpecialSubscription))
-      continue;
-
-    for (var j = 0; j < subscription.filters.length; j++)
-    {
-      var filter = subscription.filters[j];
-      if (filter instanceof WhitelistFilter && /^@@\|\|([^\/:]+)\^\$document$/.test(filter.text))
-        continue;
-
-      if (!(filter.text in seenFilter))
-        remove.push(filter);
-    }
-  }
-
-  for (var i = 0; i < remove.length; i++)
-    FilterStorage.removeFilter(remove[i]);
-
-  $("#rawFilters").hide();
 }
 
 // Called when user explicitly requests filter list updates
 function updateFilterLists()
 {
-  for (var i = 0; i < FilterStorage.subscriptions.length; i++)
-  {
-    var subscription = FilterStorage.subscriptions[i];
-    if (subscription instanceof DownloadableSubscription)
-      Synchronizer.execute(subscription, true, true);
-  }
+  // Without the URL parameter this will update all subscriptions
+  updateSubscription();
 }
 
 // Adds a subscription entry to the UI.
 function addSubscriptionEntry(subscription)
 {
   var template = document.getElementById("subscriptionTemplate");
   var element = template.cloneNode(true);
   element.removeAttribute("id");
   element._subscription = subscription;
 
   var removeButton = element.getElementsByClassName("subscriptionRemoveButton")[0];
   removeButton.setAttribute("title", removeButton.textContent);
   removeButton.textContent = "\xD7";
   removeButton.addEventListener("click", function()
   {
     if (!confirm(i18n.getMessage("global_remove_subscription_warning")))
       return;
 
-    FilterStorage.removeSubscription(subscription);
+    removeSubscription(subscription.url);
   }, false);
-  if (Prefs.additional_subscriptions.indexOf(subscription.url) != -1)
-    removeButton.style.visibility = "hidden";
+
+  getPref("additional_subscriptions", function(additionalSubscriptions)
+  {
+    if (additionalSubscriptions.indexOf(subscription.url) != -1)
+      removeButton.style.visibility = "hidden";
+  });
 
   var enabled = element.getElementsByClassName("subscriptionEnabled")[0];
   enabled.addEventListener("click", function()
   {
-    if (subscription.disabled == !enabled.checked)
-      return;
-
-    subscription.disabled = !enabled.checked;
+    subscription.disabled = !subscription.disabled;
+    toggleSubscription(subscription.url, true);
   }, false);
 
   updateSubscriptionInfo(element);
 
   document.getElementById("filterLists").appendChild(element);
 }
 
 function setLinks(id)
 {
   var element = document.getElementById(id);
   if (!element)
     return;
 
   var links = element.getElementsByTagName("a");
   for (var i = 0; i < links.length; i++)
   {
     if (typeof arguments[i + 1] == "string")
     {
       links[i].href = arguments[i + 1];
       links[i].setAttribute("target", "_blank");
     }
     else if (typeof arguments[i + 1] == "function")
     {
       links[i].href = "javascript:void(0);";
       links[i].addEventListener("click", arguments[i + 1], false);
     }
   }
 }
+
+ext.onMessage.addListener(function(message)
+{
+  switch (message.type)
+  {
+    case "app.respond":
+      switch (message.action)
+      {
+        case "addSubscription":
+          var subscription = message.args[0];
+          startSubscriptionSelection(subscription.title, subscription.url);
+          break;
+        case "focusSection":
+          var tabs = document.getElementsByClassName("ui-tabs-panel");
+          for (var i = 0; i < tabs.length; i++)
+          {
+            var found = tabs[i].querySelector(
+              "[data-section='" + message.args[0] + "']"
+            );
+            if (!found)
+              continue;
+
+            var previous = document.getElementsByClassName("focused");
+            if (previous.length > 0)
+              previous[0].classList.remove("focused");
+
+            var tab = $("[href='#" + tabs[i].id + "']");
+            $("#tabs").tabs("select", tab.parent().index());
+            found.classList.add("focused");
+          }
+          break;
+      }
+      break;
+    case "filters.respond":
+      onFilterMessage(message.action, message.args[0]);
+      break;
+    case "prefs.respond":
+      onPrefMessage(message.action, message.args[0]);
+      break;
+    case "subscriptions.respond":
+      onSubscriptionMessage(message.action, message.args[0]);
+      break;
+  }
+});