Issue 5347 - Do not show composer menu item on Firefox for Android

lib/filterComposer.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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/>.
  */
 
 /** @module filterComposer */
 
 "use strict";
 
 const {defaultMatcher} = require("matcher");
 const {RegExpFilter} = require("filterClasses");
 const {FilterNotifier} = require("filterNotifier");
 const {Prefs} = require("prefs");
 const {extractHostFromFrame, stringifyURL, isThirdParty} = require("url");
 const {getKey, checkWhitelisted} = require("whitelisting");
 const {port} = require("messaging");
+const info = require("info");
 
 let readyPages = new ext.PageMap();
 
 /**
  * Checks whether the given page is ready to use the filter composer
  *
  * @param {Page} page
  * @return {boolean}
  */
 exports.isPageReady = page =>
@@ skipping 138 matching lines @@
 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);
 }
 
+function shouldDisable()
+{
+  // Disable the composer if the browser is unknown or if it's

[Manish Jethani, 2017/08/15 23:50:06]

We have to cover null and "unknown" as well, because on Gecko that's the value
until the actual name has been fetched.

+  // "Fennec" (Firefox for Android).
+  return !info.application || info.application == "unknown" ||
+         info.application == "fennec";
+}
+
 FilterNotifier.on("page.WhitelistingStateRevalidate", updateContextMenu);
 
 Prefs.on("shouldShowBlockElementMenu", () =>
 {
   ext.pages.query({}, pages =>
   {
     for (let page of pages)
       updateContextMenu(page);
   });
 });
 
 port.on("composer.ready", (message, sender) =>
 {
-  readyPages.set(sender.page, null);
+  if (!shouldDisable())
+    readyPages.set(sender.page, null);
+
   updateContextMenu(sender.page);
 });
 
 port.on("composer.openDialog", (message, sender) =>
 {
   return new Promise(resolve =>
   {
     ext.windows.create({
       url: ext.getURL("composer.html"),
       left: 50,
@@ skipping 38 matching lines @@
   });
 });
 
 port.on("composer.quoteCSS", (message, sender) =>
 {
   return quoteCSS(message.CSS);
 });
 
 ext.pages.onLoading.addListener(page =>
 {
+  if (shouldDisable())

[Manish Jethani, 2017/08/15 23:50:06]

If we simply cut off the communication between composer.postload.js and this
file in these two places, it does the trick of "disabling" the composer.

Firefox for Android for one doesn't have a popup, nor does it have context
menus, therefore the UI for "Block element" will never be shown.

+    return;
+
   page.sendMessage({type: "composer.content.finished"});
 });