Issue 3472 - Made sure that "Block element" option is shown after page load

popup.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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;
 
 var Filter = require("filterClasses").Filter;
 var FilterStorage = require("filterStorage").FilterStorage;
 var Prefs = require("prefs").Prefs;
 var isPageWhitelisted = require("whitelisting").isPageWhitelisted;
 var getDecodedHostname = require("url").getDecodedHostname;
 
 var page = null;
 
-function init()
+function onLoad()
 {
   ext.pages.query({active: true, lastFocusedWindow: true}, function(pages)
   {
     page = pages[0];
 
     // Mark page as 'local' or 'nohtml' to hide non-relevant elements
     if (!page || (page.url.protocol != "http:" &&
                   page.url.protocol != "https:"))
       document.body.classList.add("local");
     else if (!backgroundPage.htmlPages.has(page))
@@ skipping 10 matching lines @@
 
       page.sendMessage({type: "get-clickhide-state"}, function(response)
       {
         if (response && response.active)
           document.body.classList.add("clickhide-active");
       });
     }
   });
 
   // Attach event listeners
+  ext.onMessage.addListener(onMessage);
   document.getElementById("enabled").addEventListener("click", toggleEnabled, false);
   document.getElementById("clickhide").addEventListener("click", activateClickHide, false);
   document.getElementById("clickhide-cancel").addEventListener("click", cancelClickHide, false);
   document.getElementById("options").addEventListener("click", function()
   {
     ext.showOptions();
   }, false);
 
   // Set up collapsing of menu items
   var collapsers = document.getElementsByClassName("collapse");
   for (var i = 0; i < collapsers.length; i++)
   {
     var collapser = collapsers[i];
     collapser.addEventListener("click", toggleCollapse, false);
     if (!Prefs[collapser.dataset.option])
       document.getElementById(collapser.dataset.collapsable).classList.add("collapsed");
   }
 }
-window.addEventListener("DOMContentLoaded", init, false);
+
+function onUnload()
+{
+  ext.onMessage.removeListener(onMessage);
+}
+
+function onMessage(message, sender, callback)
+{
+  if (message.type == "report-html-page"
+      && backgroundPage.htmlPages.has(page))

[Sebastian Noack, 2016/01/09 00:01:50]

This check is redundant. Or if you want to keep it for consistence, please move
that logic including the DOM manipulation below to a function that is called
here as well when checking initially.

[Thomas Greiner, 2016/01/12 11:35:17]

Unfortunately, it's not redundant. Any page could've sent this message so there
needs to be an extra check to ensure that it concerns the page the popup is
associated with.

Generally, I'd like to avoid creating a function for one line of code,
especially since I can't use `document.body.classList.toggle("nohtml",
!backgroundPage.htmlPages.has(page))` due to Safari 6.1. Therefore I'm checking
the origin of the page because comparing `sender.page == page` doesn't work and
implementing it doesn't appear to be worth it.

[Sebastian Noack, 2016/01/12 16:09:16]

Acknowledged.
I don't think that I agree. But it's probably not too important. LGTM

+    document.body.classList.remove("nohtml");
+}
 
 function toggleEnabled()
 {
   var disabled = document.body.classList.toggle("disabled");
   if (disabled)
   {
     var host = getDecodedHostname(page.url).replace(/^www\./, "");
     var filter = Filter.fromText("@@||" + host + "^$document");
     if (filter.subscriptions.length && filter.disabled)
       filter.disabled = false;
@@ skipping 36 matching lines @@
   document.body.classList.remove("clickhide-active");
   page.sendMessage({type: "clickhide-deactivate"});
 }
 
 function toggleCollapse(event)
 {
   var collapser = event.currentTarget;
   Prefs[collapser.dataset.option] = !Prefs[collapser.dataset.option];
   collapser.parentNode.classList.toggle("collapsed");
 }
+
+document.addEventListener("DOMContentLoaded", onLoad, false);
+window.addEventListener("unload", onUnload, false);