Issue 3842 - Split up the logic updating the icon and context menu

lib/filterComposer.js

Index: lib/filterComposer.js
===================================================================
--- a/lib/filterComposer.js
+++ b/lib/filterComposer.js
@@ -19,12 +19,27 @@
 
 "use strict";
 
+let {defaultMatcher} = require("matcher");
+let {RegExpFilter} = require("filterClasses");
+let {FilterNotifier} = require("filterNotifier");
+let {Prefs} = require("prefs");
 let {extractHostFromFrame, stringifyURL, isThirdParty} = require("url");
 let {getKey, checkWhitelisted} = require("whitelisting");
-let {defaultMatcher} = require("matcher");
-let {RegExpFilter} = require("filterClasses");
 let {port} = require("messaging");
 
+let readyPages = new ext.PageMap();
+
+/**
+ * Checks whether the given page is ready to use the filter composer
+ *
+ * @param {Page} page
+ * @return {boolean}
+ */
+exports.isPageReady = function(page)
+{
+  return readyPages.has(page);
+};
+
 function isValidString(s) {
   return s && s.indexOf("\0") == -1;
 }
@@ -138,10 +153,44 @@
   return {filters: filters, selectors: selectors};
 }
 
+let contextMenuItem = {
+  title: ext.i18n.getMessage("block_element"),
+  contexts: ["image", "video", "audio"],
+  onclick: page =>
+  {
+    page.sendMessage({type: "composer.content.contextMenuClicked"});
+  }
+};
+
+function updateContextMenu(page, filter)
+{
+  page.contextMenus.remove(contextMenuItem);
+
+  if (typeof filter == "undefined")
+    filter = checkWhitelisted(page);
+  if (!filter && Prefs.shouldShowBlockElementMenu && readyPages.has(page))
+    page.contextMenus.create(contextMenuItem);
+}
+
+FilterNotifier.addListener((action, page, filter) =>
+{
+  if (action == "page.WhitelistingStateRevalidate")
+    updateContextMenu(page, filter);
+});
+
+Prefs.on("shouldShowBlockElementMenu", () =>
+{
+  ext.pages.query({}, pages =>
+  {
+    for (let page of pages)
+      updateContextMenu(page);
+  });
+});
+
 port.on("composer.ready", (message, sender) =>
 {
-  htmlPages.set(sender.page, null);
-  refreshIconAndContextMenu(sender.page);
+  readyPages.set(sender.page, null);
+  updateContextMenu(sender.page);
 });
 
 port.on("composer.openDialog", (message, sender) =>