[adblockpluschrome] Issue 3596 - Added support for CSS property filters to devtools panel

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * 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
@@ skipping 174 matching lines @@
   try
   {
     return element.contentDocument;
   }
   catch (e)
   {
     return null;
   }
 }
 
-function ElementHidingTracer(selectors)
+function ElementHidingTracer()
 {
-  this.selectors = selectors;
+  this.filters = [];
 
   this.changedNodes = [];
   this.timeout = null;
+  this.started = false;
 
   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)
+  start: function()
   {
-    var matchedSelectors = [];
+    let _start = () => {
+      this.trace();
+      this.started = true;
+    };
 
-    // Find all selectors that match any hidden element inside the given nodes.
-    for (var i = 0; i < this.selectors.length; i++)
+    if (document.readyState == "loading")
+      document.addEventListener("DOMContentLoaded", _start);
+    else
+      _start();
+  },
+
+ addFilters: function(filters)
+  {
+    if (this.started)
+      window.setTimeout(() => {
+        this.checkNodes([document], filters);
+      }, 0);
+
+    Array.prototype.push.apply(this.filters, filters);
+  },
+
+  checkNodes: function(nodes, filters)
+  {
+    let matchedFilters = [];
+
+    for (let [filter, selector] of filters)
     {
-      var selector = this.selectors[i];
+      nodes: for (let node of nodes)
+      {
+        let elements = node.querySelectorAll(selector);
 
-      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++)
+        for (let element of elements)
         {
           // 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")
+          if (getComputedStyle(element).display == "none")
           {
-            matchedSelectors.push(selector);
-            matched = true;
-            break;
+            matchedFilters.push(filter.replace(/^.*?##/, ""));
+            break nodes;
           }
         }
-
-        if (matched)
-          break;
       }
     }
 
-    if (matchedSelectors.length > 0)
+    if (matchedFilters.length > 0)
       ext.backgroundPage.sendMessage({
         type: "devtools.traceElemHide",
-        selectors: matchedSelectors
+        selectors: matchedFilters
       });
   },
 
   onTimeout: function()
   {
-    this.checkNodes(this.changedNodes);
+    this.checkNodes(this.changedNodes, this.filters);
     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 (!document.contains(this.changedNodes[i]))
@@ skipping 42 matching lines @@
 
     // 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([document]);
+    this.checkNodes([document], this.filters);
 
     this.observer.observe(
       document,
       {
         childList: true,
         attributes: true,
         subtree: true
       }
     );
   },
@@ skipping 157 matching lines @@
             var shadow = shadowRoot(this);
             return shadow == ourShadowRoot ? null : shadow;
           }
         });
       }, null);
     }
 
     return shadow;
   },
 
-  addSelectors: function(selectors)
+  addSelectors: function(selectors, filters)
   {
-    if (selectors.length == 0)
+    if (!selectors.length)
       return;
 
+    if (this.tracer)
+    {
+      let tracedFilters = [];
+      for (let i = 0; i < selectors.length; i++)
+        tracedFilters.push([filters ? filters[i] : selectors[i], selectors[i]]);
+      this.tracer.addFilters(tracedFilters);
+    }
+
     if (!this.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.
       this.style = document.createElement("style");
       (this.shadow || document.head
                    || document.documentElement).appendChild(this.style);
 
@@ skipping 29 matching lines @@
     {
       var selector = selectors.slice(i, i + this.selectorGroupSize).join(", ");
       this.style.sheet.insertRule(selector + "{display: none !important;}",
                                   this.style.sheet.cssRules.length);
     }
   },
 
   apply: function()
   {
     var selectors = null;
-    var elemHideEmulationLoaded = false;
 
     var checkLoaded = function()
     {
-      if (!selectors || !elemHideEmulationLoaded)
-        return;
-
       if (this.tracer)
         this.tracer.disconnect();
       this.tracer = null;
 
+      if (selectors.trace)
+        this.tracer = new ElementHidingTracer();
+
       if (this.style && this.style.parentElement)
         this.style.parentElement.removeChild(this.style);
       this.style = null;
 
-      this.addSelectors(selectors.selectors);
+      if (selectors.selectors)
+        this.addSelectors(selectors.selectors);
+
       this.elemHideEmulation.apply();
 
-      if (selectors.trace)
-        this.tracer = new ElementHidingTracer(selectors.selectors);
+      if (this.tracer)
+        this.tracer.start();
     }.bind(this);
 
-    ext.backgroundPage.sendMessage({type: "get-selectors"}, function(response)
+    ext.backgroundPage.sendMessage({type: "get-selectors"}, response =>
     {
       selectors = response;
-      checkLoaded();
-    });
-
-    this.elemHideEmulation.load(function()
-    {
-      elemHideEmulationLoaded = true;
-      checkLoaded();
+      this.elemHideEmulation.load(checkLoaded);
     });
   }
 };
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   wrapWebSocket();
 
   var elemhide = new ElemHide();
   elemhide.apply();
 
   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);
   }, true);
 }