Issue 2082 - Detect existing tabs when loading extension on Safari

safari/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 215 matching lines @@
     for (var id in tab._pages)
     {
       if (id != page._id)
         forgetPage(id);
     }
 
     if (isPageActive(page))
       updateToolbarItemForPage(page, tab.browserWindow);
   };
 
   var addPage = function(tab, url, prerendered)

[Sebastian Noack, 2015/03/03 19:51:34]

This function is new.

   {
     var pageId = ++pageCounter;
 
     if (!('_pages' in tab))
       tab._pages = Object.create(null);
 
     var page = new Page(pageId, tab, url);
     pages[pageId] = tab._pages[pageId] = page;
 

[kzar, 2015/03/04 10:46:57]

Seems a shame you stripped out the useful comment when splitting this off into a
separate function.

[Sebastian Noack, 2015/03/04 11:04:35]

I've re-added that comment. Also added some more comments explaining what the
new code does.

+    // When a new page is shown, forget the previous page associated
+    // with its tab, and reset the toolbar item if necessary.
+    // Note that it wouldn't be sufficient to do that when the old
+    // page is unloading, because Safari dispatches window.onunload
+    // only when reloading the page or following links, but not when
+    // you enter a new URL in the address bar.
     if (!prerendered)
       replacePage(page);
 
     return pageId;
   };
 
   ext.pages = {
     open: function(url, callback)
     {
       var tab = safari.application.activeBrowserWindow.openTab();
@@ skipping 43 matching lines @@
       return;
 
     // when a tab is closed, forget the previous page associated with that
     // tab. Note that it wouldn't be sufficient do that when the old page
     // is unloading, because Safari dispatches window.onunload only when
     // reloading the page or following links, but not when closing the tab.
     for (var id in event.target._pages)
       forgetPage(id);
   }, true);
 
+  // We generally rely on content scripts to report new pages,
+  // since Safari's extension API doesn't consider pre-rendered
+  // pages. However, when the extension initializes we have to
+  // use  Safari's extension API to detect existing tabs.
   safari.application.browserWindows.forEach(function(win)

[Sebastian Noack, 2015/03/03 19:51:34]

This is where we detect existing tabs now.

   {
     for (var i = 0; i < win.tabs.length; i++)
     {
       var tab = win.tabs[i];
       var url = tab.url;
 
+      // For the new tab page the url property is undefined.
       if (url)
         addPage(tab, url, false);
     }
   });
 
 
   /* Web requests */
 
   ext.webRequest = {
     onBeforeRequest: new ext._EventTarget(),
@@ skipping 352 matching lines @@
         tab.activate();
         if (callback)
           callback(page);
         return;
       }
     }
 
     ext.pages.open(optionsUrl, callback);
   };
 })();