Issue 154 - Added devtools panel showing blocked and blockable items

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
- * Copyright (C) 2006-2015 Eyeo GmbH
+ * Copyright (C) 2006-2016 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 SELECTOR_GROUP_SIZE = 20;
 
 var typeMap = {
   "img": "IMAGE",
   "input": "IMAGE",
+  "picture": "IMAGE",
   "audio": "MEDIA",
   "video": "MEDIA",
   "frame": "SUBDOCUMENT",
-  "iframe": "SUBDOCUMENT"
+  "iframe": "SUBDOCUMENT",
+  "object": "OBJECT",
+  "embed": "OBJECT"
 };
+
+function getURLsFromObjectElement(element)
+{
+  var url = element.getAttribute("data");
+  if (url)
+    return [url];
+
+  for (var i = 0; i < element.children.length; i++)
+  {
+    var child = element.children[i];
+    if (child.localName != "param")
+      continue;
+
+    var name = child.getAttribute("name");
+    if (name != "movie"  && // Adobe Flash
+        name != "source" && // Silverlight
+        name != "src"    && // Real Media + Quicktime
+        name != "FileName") // Windows Media
+      continue;
+
+    var value = child.getAttribute("value");
+    if (!value)
+      continue;
+
+    return [value];
+  }
+
+  return [];
+}
+
+function getURLsFromAttributes(element)
+{
+  var urls = [];
+
+  if (element.src)
+    urls.push(element.src);
+
+  if (element.srcset)
+  {
+    var candidates = element.srcset.split(",");
+    for (var i = 0; i < candidates.length; i++)
+    {
+      var url = candidates[i].trim().replace(/\s+\S+$/, "");
+      if (url)
+        urls.push(url);
+    }
+  }
+
+  return urls;
+}
+
+function getURLsFromMediaElement(element)
+{
+  var urls = getURLsFromAttributes(element);
+
+  for (var i = 0; i < element.children.length; i++)
+  {
+    var child = element.children[i];
+    if (child.localName == "source" || child.localName == "track")
+      urls.push.apply(urls, getURLsFromAttributes(child));
+  }
+
+  if (element.poster)
+    urls.push(element.poster);
+
+  return urls;
+}
+
+function getURLsFromElement(element)
+{
+  var urls;
+  switch (element.localName)
+  {
+    case "object":
+      urls = getURLsFromObjectElement(element);
+      break;
+
+    case "video":
+    case "audio":
+    case "picture":
+      urls = getURLsFromMediaElement(element);
+      break;
+
+    default:
+      urls = getURLsFromAttributes(element);
+      break;
+  }
+
+  for (var i = 0; i < urls.length; i++)
+  {
+    if (/^(?!https?:)[\w-]+:/i.test(urls[i]))
+      urls.splice(i--, 1);
+  }
+
+  return urls;
+}
 
 function checkCollapse(element)
 {
   var tag = element.localName;
   if (tag in typeMap)
   {
     // This element failed loading, did we block it?
-    var url = element.src;
-    if (!url || !/^https?:/i.test(url))
+    var urls = getURLsFromElement(element);
+    if (urls.length == 0)
       return;
 
     ext.backgroundPage.sendMessage(
       {
         type: "should-collapse",
-        url: url,
-        mediatype: typeMap[tag]
+        urls: urls,
+        mediatype: typeMap[tag],
+        baseURL: document.location.href
       },
 
       function(response)
       {
         if (response && element.parentNode)
         {
           var property = "display";
           var value = "none";
 
           // <frame> cannot be removed, doing that will mess up the frameset
           if (tag == "frame")
           {
             property = "visibility";
             value = "hidden";
           }
 
           // <input type="image"> elements try to load their image again
           // when the "display" CSS property is set. So we have to check
           // that it isn't already collapsed to avoid an infinite recursion.
           if (element.style.getPropertyValue(property) != value ||
               element.style.getPropertyPriority(property) != "important")
             element.style.setProperty(property, value, "important");
         }
       }
     );
   }
+
+  window.collapsing = true;
 }
 
 function checkSitekey()
 {
   var attr = document.documentElement.getAttribute("data-adblockkey");
   if (attr)
     ext.backgroundPage.sendMessage({type: "add-sitekey", token: attr});
 }
 
-function isInlineFrame(element)
-{
-  var contentDocument;
+function getContentDocument(element)
+{
   try
   {
-    contentDocument = element.contentDocument;
+    return element.contentDocument;
   }
   catch (e)
   {
-    return false;  // third-party
-  }
-
-  if (!contentDocument)
-    return false;  // not a frame
-
-  return contentDocument.location.protocol == "about:";
-}
-
-function resolveURL(url)
-{
-  var a = document.createElement("a");
-  a.href = url;
-  return a.href;
-}
-
-function traceHiddenElements(document, selectors)
-{
-  function check(element)
+    return null;
+  }
+}
+
+function ElementHidingTracer(document, selectors)
+{
+  this.document = document;
+  this.selectors = selectors;
+
+  this.changedNodes = [];
+  this.timeout = null;
+
+  this.observer = new MutationObserver(this.observe.bind(this));
+  this.trace = this.trace.bind(this);
+
+  if (document.readyState == "loading")
+    document.addEventListener("DOMContentLoaded", this.trace);
+  else
+    this.trace();
+}
+ElementHidingTracer.prototype = {
+  checkNodes: function(nodes)
   {
     var matchedSelectors = [];
 
-    for (var i = 0; i < selectors.length; i++)
-    {
-      var selector = selectors[i];
-      var elements = document.querySelectorAll(selector);
-
-      for (var j = 0; j < elements.length; j++)
-      {
-        if (getComputedStyle(elements[j]).display == "none")
+    // Find all selectors that match any hidden element inside the given nodes.
+    for (var i = 0; i < this.selectors.length; i++)
+    {
+      var selector = this.selectors[i];
+
+      for (var j = 0; j < nodes.length; j++)
+      {
+        var elements = nodes[j].querySelectorAll(selector);
+        var matched = false;
+
+        for (var k = 0; k < elements.length; k++)
         {
-          matchedSelectors.push(selector);
+          // Only consider selectors that actually have an effect on the
+          // computed styles, and aren't overridden by rules with higher
+          // priority, or haven't been circumvented in a different way.
+          if (getComputedStyle(elements[k]).display == "none")
+          {
+            matchedSelectors.push(selector);
+            matched = true;
+            break;
+          }
+        }
+
+        if (matched)
+          break;
+      }
+    }
+
+    if (matchedSelectors.length > 0)
+      ext.backgroundPage.sendMessage({
+        type: "trace-elemhide",
+        selectors: matchedSelectors
+      });
+  },
+
+  onTimeout: function()
+  {
+    this.checkNodes(this.changedNodes);
+    this.changedNodes = [];
+    this.timeout = null;
+  },
+
+  observe: function(mutations)
+  {
+    // Forget previously changed nodes that are no longer in the DOM.
+    for (var i = 0; i < this.changedNodes.length; i++)
+    {
+      if (!this.document.contains(this.changedNodes[i]))
+        this.changedNodes.splice(i--, 1);
+    }
+
+    for (var j = 0; j < mutations.length; j++)
+    {
+      var mutation = mutations[j];
+      var node = mutation.target;
+
+      // Ignore mutations of nodes that aren't in the DOM anymore.
+      if (!this.document.contains(node))
+        continue;
+
+      // Since querySelectorAll() doesn't consider the root itself
+      // and since CSS selectors can also match siblings, we have
+      // to consider the parent node for attribute mutations.
+      if (mutation.type == "attributes")
+        node = node.parentNode;
+
+      var addNode = true;
+      for (var k = 0; k < this.changedNodes.length; k++)
+      {
+        var previouslyChangedNode = this.changedNodes[k];
+
+        // If we are already going to check an ancestor of this node,
+        // we can ignore this node, since it will be considered anyway
+        // when checking one of its ancestors.
+        if (previouslyChangedNode.contains(node))
+        {
+          addNode = false;
           break;
         }
-      }
-    }
-
-    if (matchedSelectors.length > 0)
-      ext.backgroundPage.sendMessage({type: "trace-elemhide", selectors: matchedSelectors});
-  }
-
-  function trace()
-  {
-    check();
-
-    new MutationObserver(check).observe(
-      document,
+
+        // If this node is an ancestor of a node that previously changed,
+        // we can ignore that node, since it will be considered anyway
+        // when checking one of its ancestors.
+        if (node.contains(previouslyChangedNode))
+          this.changedNodes.splice(k--, 1);
+      }
+
+      if (addNode)
+        this.changedNodes.push(node);
+    }
+
+    // Check only nodes whose descendants have changed, and not more often
+    // than once a second. Otherwise large pages with a lot of DOM mutations
+    // (like YouTube) freeze when the devtools panel is active.
+    if (this.timeout == null)
+      this.timeout = setTimeout(this.onTimeout.bind(this), 1000);
+  },
+
+  trace: function()
+  {
+    this.checkNodes([this.document]);
+
+    this.observer.observe(
+      this.document,
       {
         childList: true,
         attributes: true,
         subtree: true
       }
     );
-  }
-
-  if (document.readyState == "loading")
-    document.addEventListener("DOMContentLoaded", trace);
-  else
-    trace();
-}
+  },
+
+  disconnect: function()
+  {
+    this.document.removeEventListener("DOMContentLoaded", this.trace);
+    this.observer.disconnect();
+    clearTimeout(this.timeout);
+  }
+};
 
 function reinjectRulesWhenRemoved(document, style)
 {
   var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
   if (!MutationObserver)
     return;
 
   var observer = new MutationObserver(function(mutations)
   {
     var isStyleRemoved = false;
@@ skipping 11 matching lines @@
     observer.disconnect();
 
     var n = document.styleSheets.length;
     if (n == 0)
       return;
 
     var stylesheet = document.styleSheets[n - 1];
     ext.backgroundPage.sendMessage(
       {type: "get-selectors"},
 
-      function(selectors)
-      {
+      function(response)
+      {
+        var selectors = response.selectors;
         while (selectors.length > 0)
         {
           var selector = selectors.splice(0, SELECTOR_GROUP_SIZE).join(", ");
 
           // Using non-standard addRule() here. This is the only way
           // to add rules at the end of a cross-origin stylesheet
           // because we don't know how many rules are already in there
           stylesheet.addRule(selector, "display: none !important;");
         }
       }
     );
   });
 
   observer.observe(style.parentNode, {childList: true});
+  return observer;
 }
 
 function convertSelectorsForShadowDOM(selectors)
 {
   var result = [];
   var prefix = "::content ";
 
   for (var i = 0; i < selectors.length; i++)
   {
     var selector = selectors[i];
+    if (selector.indexOf(",") == -1)
+    {
+      result.push(prefix + selector);
+      continue;
+    }
+
     var start = 0;
     var sep = "";
-
     for (var j = 0; j < selector.length; j++)
     {
       var chr = selector[j];
       if (chr == "\\")
         j++;
       else if (chr == sep)
         sep = "";
-      else if (chr == '"' || chr == "'")
-        sep = chr;
-      else if (chr == "," && sep == "")
-      {
-        result.push(prefix + selector.substring(start, j));
-        start = j + 1;
+      else if (sep == "")
+      {
+        if (chr == '"' || chr == "'")
+          sep = chr;
+        else if (chr == ",")
+        {
+          result.push(prefix + selector.substring(start, j));
+          start = j + 1;
+        }
       }
     }
 
     result.push(prefix + selector.substring(start));
   }
 
   return result;
 }
 
 function init(document)
 {
+  var shadow = null;
+  var style = null;
+  var observer = null;
+  var tracer = null;
+  var propertyFilters = new CSSPropertyFilters(window, addElemHideSelectors);
+
   // Use Shadow DOM if available to don't mess with web pages that rely on
   // the order of their own <style> tags (#309).
   //
   // However, creating a shadow root breaks running CSS transitions. So we
   // have to create the shadow root before transistions might start (#452).
   //
-  // Also, we can't use shadow DOM on Google Docs, since it breaks printing
-  // there (#1770).
-  var shadow = null;
-  if ("createShadowRoot" in document.documentElement && document.domain != "docs.google.com")
+  // Also, using shadow DOM causes issues on some Google websites,
+  // including Google Docs and Gmail (#1770, #2602).
+  if ("createShadowRoot" in document.documentElement && !/\.google\.com$/.test(document.domain))
   {
     shadow = document.documentElement.createShadowRoot();
     shadow.appendChild(document.createElement("shadow"));
   }
 
-  // Sets the currently used CSS rules for elemhide filters
-  var setElemhideCSSRules = function(response)
-  {
-    if (response.selectors.length == 0)
+  function addElemHideSelectors(selectors)
+  {
+    if (selectors.length == 0)
       return;
 
-    var style = document.createElement("style");
-    style.setAttribute("type", "text/css");
-
-    var selectors = response.selectors;
+    if (!style)
+    {
+      // Create <style> element lazily, only if we add styles. Add it to
+      // the shadow DOM if possible. Otherwise fallback to the <head> or
+      // <html> element. If we have injected a style element before that
+      // has been removed (the sheet property is null), create a new one.
+      style = document.createElement("style");
+      (shadow || document.head || document.documentElement).appendChild(style);
+
+      // It can happen that the frame already navigated to a different
+      // document while we were waiting for the background page to respond.
+      // In that case the sheet property will stay null, after addind the
+      // <style> element to the shadow DOM.
+      if (!style.sheet)
+        return;
+
+      observer = reinjectRulesWhenRemoved(document, style);
+    }
+
+    // If using shadow DOM, we have to add the ::content pseudo-element
+    // before each selector, in order to match elements within the
+    // insertion point.
     if (shadow)
-    {
-      shadow.appendChild(style);
       selectors = convertSelectorsForShadowDOM(selectors);
-    }
-    else
-    {
-      // Try to insert the style into the <head> tag, inserting directly under the
-      // document root breaks dev tools functionality:
-      // http://code.google.com/p/chromium/issues/detail?id=178109
-      (document.head || document.documentElement).appendChild(style);
-    }
-
-    var setRules = function()
-    {
-      // The sheet property might not exist yet if the
-      // <style> element was created for a sub frame
-      if (!style.sheet)
-      {
-        setTimeout(setRules, 0);
+
+    // WebKit (and Blink?) apparently chokes when the selector list in a
+    // CSS rule is huge. So we split the elemhide selectors into groups.
+    while (selectors.length > 0)
+    {
+      var selector = selectors.splice(0, SELECTOR_GROUP_SIZE).join(", ");
+      style.sheet.addRule(selector, "display: none !important;");
+    }
+  };
+
+  var updateStylesheet = function()
+  {
+    var selectors = null;
+    var CSSPropertyFiltersLoaded = false;
+
+    var checkLoaded = function()
+    {
+      if (!selectors || !CSSPropertyFiltersLoaded)
         return;
-      }
-
-      // WebKit apparently chokes when the selector list in a CSS rule is huge.
-      // So we split the elemhide selectors into groups.
-      for (var i = 0; selectors.length > 0; i++)
-      {
-        var selector = selectors.splice(0, SELECTOR_GROUP_SIZE).join(", ");
-        style.sheet.insertRule(selector + " { display: none !important; }", i);
-      }
-
-      if (response.trace)
-        traceHiddenElements(document, response.selectors);
+
+      if (observer)
+        observer.disconnect();
+      observer = null;
+
+      if (tracer)
+        tracer.disconnect();
+      tracer = null;
+
+      if (style && style.parentElement)
+        style.parentElement.removeChild(style);
+      style = null;
+
+      addElemHideSelectors(selectors.selectors);
+      propertyFilters.apply();
+
+      if (selectors.trace)
+        tracer = new ElementHidingTracer(document, selectors.selectors);
     };
 
-    setRules();
-    reinjectRulesWhenRemoved(document, style);
+    ext.backgroundPage.sendMessage({type: "get-selectors"}, function(response)
+    {
+      selectors = response;
+      checkLoaded();
+    });
+
+    propertyFilters.load(function()
+    {
+      CSSPropertyFiltersLoaded = true;
+      checkLoaded();
+    });
   };
+
+  updateStylesheet();
 
   document.addEventListener("error", function(event)
   {
     checkCollapse(event.target);
   }, true);
 
   document.addEventListener("load", function(event)
   {
     var element = event.target;
 
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
 
-    // prior to Chrome 37, content scripts cannot run on about:blank,
-    // about:srcdoc and javascript: URLs. Moreover, as of Chrome 40
-    // "load" and "error" events aren't dispatched there. So we have
-    // to apply element hiding and collapsing from the parent frame.
-    if (/\bChrome\//.test(navigator.userAgent) && isInlineFrame(element))
-    {
-      init(element.contentDocument);
-
-      for (var tagName in typeMap)
-        Array.prototype.forEach.call(element.contentDocument.getElementsByTagName(tagName), checkCollapse);
+    if (/\bChrome\//.test(navigator.userAgent))
+    {
+      var contentDocument = getContentDocument(element);
+      if (contentDocument)
+      {
+        var contentWindow = contentDocument.defaultView;
+        if (contentDocument instanceof contentWindow.HTMLDocument)
+        {
+          // Prior to Chrome 37, content scripts cannot run in
+          // dynamically created frames. Also on Chrome 37-40
+          // document_start content scripts (like this one) don't
+          // run either in those frames due to https://crbug.com/416907.
+          // So we have to apply element hiding from the parent frame.
+          if (!("init" in contentWindow))
+            init(contentDocument);
+
+          // Moreover, "load" and "error" events aren't dispatched for elements
+          // in dynamically created frames due to https://crbug.com/442107.
+          // So we also have to apply element collpasing from the parent frame.
+          if (!contentWindow.collapsing)
+            Array.prototype.forEach.call(
+              contentDocument.querySelectorAll(Object.keys(typeMap).join(",")),
+              checkCollapse
+            );
+        }
+      }
     }
   }, true);
 
-  ext.backgroundPage.sendMessage({type: "get-selectors"}, setElemhideCSSRules);
+  return updateStylesheet;
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
-  init(document);
-}
+  window.updateStylesheet = init(document);
+}