Issue 1983 - Dispatch onLoading event for prerendered pages

chrome/ext/background.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
@@ skipping 84 matching lines @@
       {
         callback(tabs.map(function(tab)
         {
           return new Page(tab);
         }));
       });
     },
     onLoading: new ext._EventTarget()
   };
 
+  chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab)
+  {
+    if (changeInfo.status == "loading")
+      ext.pages.onLoading._dispatch(new Page(tab));
+  });
+
   chrome.webNavigation.onBeforeNavigate.addListener(function(details)
   {
     if (details.frameId == 0)
     {
       ext._removeFromAllPageMaps(details.tabId);
 
       chrome.tabs.get(details.tabId, function()
       {
+        // If the tab is prerendered, chrome.tabs.get() sets
+        // chrome.runtime.lastError and we have to dispatch the onLoading event,
+        // since the onUpdated event isn't dispatched for prerendered tabs.
+        // However, we have to keep relying on the unUpdated event for tabs that
+        // are already visible. Otherwise browser action changes get overridden
+        // when Chrome automatically resets them on navigation.
         if (chrome.runtime.lastError)
         {
-          // If the tab is prerendered, chrome.tabs.get() sets
-          // chrome.runtime.lastError and we have to immediately dispatch the
-          // "onLoading" event, since "onUpdated" events aren't dispatched for
-          // prerendered tabs. The browserAction object (see above) then take
-          // care to delay changes until the tab becomes visible.
           ext.pages.onLoading._dispatch(
             new Page({
               id: details.tabId,
               url: details.url
             })
           );
-        }
-        else
-        {
-          // If the tab is already visible, we have to delay the "onLoading"
-          // event until the tab actually switches to "loading" status.
-          // Otherwise browser action changes get overridden when Chrome
-          // automatically resets them for the new page.
-          function onUpdated(tabId, changeInfo, tab)
-          {
-            if (tabId == details.tabId && changeInfo.status == "loading")
-            {
-              chrome.tabs.onUpdated.removeListener(onUpdated);
-              chrome.tabs.onRemoved.removeListener(onRemoved);
-
-              ext.pages.onLoading._dispatch(new Page(tab));
-            }
-          }
-          chrome.tabs.onUpdated.addListener(onUpdated);
-
-          // Make sure to not leak any callbacks, in case the tab
-          // is removed before its status changes to "loading".
-          function onRemoved(tabId)
-          {
-            if (tabId == details.tabId)
-            {
-              chrome.tabs.onUpdated.removeListener(onUpdated);
-              chrome.tabs.onRemoved.removeListener(onRemoved);
-            }
-          }
-          chrome.tabs.onRemoved.addListener(onRemoved);
         }
       });
     }
   });
 
   function forgetTab(tabId)
   {
     ext._removeFromAllPageMaps(tabId);
     delete framesOfTabs[tabId];
   }
@@ skipping 370 matching lines @@
             callback(new Page(tab));
         }
         else
         {
           ext.pages.open(optionsUrl, callback);
         }
       });
     });
   };
 })();