Issue 1282 - Don't generate filters conflicting with existing exception rules

include.postload.js

Index: include.postload.js
===================================================================
--- a/include.postload.js
+++ b/include.postload.js
@@ -267,24 +267,6 @@
   return getURLsFromAttributes(element);
 }
 
-function isBlockable(element)
-{
-  if (element.id)
-    return true;
-  if (element.classList.length > 0)
-    return true;
-  if (getURLsFromElement(element).length > 0)
-    return true;
-
-  // We only generate filters based on the "style" attribute,
-  // if this is the only way we can generate a filter, and
-  // only if there are at least two CSS properties defined.
-  if (/:.+:/.test(getOriginalStyle(element)))
-    return true;
-
-  return false;
-}
-
 // Gets the absolute position of an element by walking up the DOM tree,
 // adding up offsets.
 // I hope there's a better way because it just seems absolutely stupid
@@ -301,14 +283,9 @@
 }
 
 // Adds an overlay to an element, which is probably a Flash object
-function addElementOverlay(elt) {
+function addElementOverlay(elt, callback) {
   // If this element is enclosed in an object tag, we prefer to block that instead
   if(!elt)
-    return null;
-
-  // If element doesn't have at least one of class name, ID or URL, give up
-  // because we don't know how to construct a filter rule for it
-  if(!isBlockable(elt))
     return;
 
   // If the element isn't rendered (since its or one of its ancestor's
@@ -316,23 +293,30 @@
   if (!elt.offsetParent)
     return;
 
-  var thisStyle = getComputedStyle(elt, null);
-  var overlay = document.createElement('div');
-  overlay.prisoner = elt;
-  overlay.className = "__adblockplus__overlay";
-  overlay.setAttribute('style', 'opacity:0.4; background-color:#ffffff; display:inline-box; ' + 'width:' + thisStyle.width + '; height:' + thisStyle.height + '; position:absolute; overflow:hidden; -webkit-box-sizing:border-box;');
-  var pos = getAbsolutePosition(elt);
-  overlay.style.left = pos[0] + "px";
-  overlay.style.top = pos[1] + "px";
+  generateFilters(elt, function(filters)
+  {
+    if (filters.length == 0)
+      return;
 
-  if (thisStyle.position != "static")
-    overlay.style.zIndex = thisStyle.zIndex;
-  else
-    overlay.style.zIndex = getComputedStyle(elt.offsetParent).zIndex;
+    var thisStyle = getComputedStyle(elt, null);
+    var overlay = document.createElement('div');
+    overlay.prisoner = elt;
+    overlay.className = "__adblockplus__overlay";
+    overlay.setAttribute('style', 'opacity:0.4; background-color:#ffffff; display:inline-box; ' + 'width:' + thisStyle.width + '; height:' + thisStyle.height + '; position:absolute; overflow:hidden; -webkit-box-sizing:border-box;');
+    var pos = getAbsolutePosition(elt);
+    overlay.style.left = pos[0] + "px";
+    overlay.style.top = pos[1] + "px";
 
-  // elt.parentNode.appendChild(overlay, elt);
-  document.body.appendChild(overlay);
-  return overlay;
+    if (thisStyle.position != "static")
+      overlay.style.zIndex = thisStyle.zIndex;
+    else
+      overlay.style.zIndex = getComputedStyle(elt.offsetParent).zIndex;
+
+    document.body.appendChild(overlay);
+
+    if (callback)
+      callback(overlay);
+  });
 }
 
 // Show dialog asking user whether she wants to add the proposed filters derived
@@ -443,31 +427,50 @@
   clickHide_mouseClick(ev);
 }
 
+function getBlockableElementOrAncestor(element, callback)
+{
+  if (element && element != document.documentElement
+              && element != document.body)
+  {
+    generateFilters(element, function(filters)
+    {
+      if (filters.length > 0)
+        callback(element);
+      else
+        getBlockableElementOrAncestor(element.parentElement, callback);
+    });
+  }
+  else
+  {
+    callback(null);
+  }
+}
+
 // Hovering over an element so highlight it
 function clickHide_mouseOver(e)
 {
   if (clickHide_activated == false)
     return;
 
-  var target = e.target;
-  while (target.parentNode && !isBlockable(target))
-    target = target.parentNode;
-  if (target == document.documentElement || target == document.body)
-    target = null;
+  getBlockableElementOrAncestor(e.target, function(element)
+  {
+    if (currentElement)
+      unhighlightElement(currentElement);
 
-  if (target && target instanceof HTMLElement)
-  {
-    currentElement = target;
+    if (element)
+    {
+      highlightElement(element, "#d6d84b", "#f8fa47");
+      element.addEventListener("contextmenu", clickHide_elementClickHandler, true);
+    }
 
-    highlightElement(target, "#d6d84b", "#f8fa47");
-    target.addEventListener("contextmenu", clickHide_elementClickHandler, true);
-  }
+    currentElement = element;
+  });
 }
 
 // No longer hovering over this element so unhighlight it
 function clickHide_mouseOut(e)
 {
-  if (!clickHide_activated || !currentElement)
+  if (!clickHide_activated || currentElement != e.target)
     return;
 
   unhighlightElement(currentElement);
@@ -494,6 +497,108 @@
   }
 }
 
+function generateFilters(element, callback)
+{
+  function addStyleAttributeFilter(filters, selectors)
+  {
+    var style = getOriginalStyle(element);
+    if (style && filters.length == 0)
+    {
+      ext.backgroundPage.sendMessage(
+        {
+          type: "get-filters-from-selectors",
+          selectors: [escapeCSS(element.localName) + '[style=' + quote(style) + ']']
+        },
+
+        function(response)
+        {
+          callback(filters.concat(response.filters), selectors.concat(response.selectors));
+        }
+      );
+    }
+    else
+      callback(filters, selectors);
+  }
+
+  function addElemHideFilter(filters, selectors)
+  {
+    if (selectors.length > 0)
+    {
+      ext.backgroundPage.sendMessage(
+        {
+          type: "get-filters-from-selectors",
+          selectors: selectors
+        },
+
+        function(response)
+        {
+          addStyleAttributeFilter(filters.concat(response.filters), response.selectors);
+        }
+      );
+    }
+    else
+      addStyleAttributeFilter(filters, selectors);
+  }
+
+  var filters = [];
+  var selectors = [];
+
+  if (element.id)
+    selectors.push("#" + escapeCSS(element.id));
+
+  if (element.classList.length > 0)
+  {
+    var selector = "";
+
+    for (var i = 0; i < element.classList.length; i++)
+      selector += "." + escapeCSS(element.classList[i]);
+
+    selectors.push(selector);
+  }
+
+  var urls = getURLsFromElement(element);
+  if (urls.length > 0)
+  {
+    ext.backgroundPage.sendMessage(
+      {
+        type: "check-whitelisted-urls",
+        mediatype: typeMap[element.localName],
+        urls: urls
+      },
+
+      function(whitelisted)
+      {
+        for (var i = 0; i < urls.length; i++)
+        {
+          var url = urls[i];
+
+          if (!whitelisted[url] && /^https?:/i.test(url))
+          {
+            var filter = url.replace(/^[\w\-]+:\/+(?:www\.)?/, "||");
+
+            if (filters.indexOf(filter) == -1)
+              filters.push(filter);
+
+            continue;
+          }
+
+          if (url == element.src)
+          {
+            var selector = escapeCSS(element.localName) + '[src=' + quote(element.getAttribute("src")) + ']';
+
+            if (selectors.indexOf(selector) == -1)
+              selectors.push(selector);
+          }
+        }
+
+        addElemHideFilter(filters, selectors);
+      }
+    );
+  }
+  else
+    addElemHideFilter(filters, selectors);
+}
+
 // When the user clicks, the currentElement is the one we want.
 // We should have ABP rules ready for when the
 // popup asks for them.
@@ -506,66 +611,17 @@
   if (currentElement.classList.contains("__adblockplus__overlay"))
     elt = currentElement.prisoner;
 
-  clickHideFilters = new Array();
-  selectorList = new Array();
+  generateFilters(elt, function(filters, selectors)
+  {
+    clickHide_showDialog(e.clientX, e.clientY, filters);
 
-  var addSelector = function(selector)
-  {
-    if (selectorList.indexOf(selector) != -1)
-      return;
+    // Highlight the elements specified by selector in yellow
+    if (selectors.length > 0)
+      highlightElements(selectors.join(","));
 
-    clickHideFilters.push(document.domain + "##" + selector);
-    selectorList.push(selector);
-  };
-
-  if (elt.id)
-    addSelector("#" + escapeCSS(elt.id));
-
-  if (elt.classList.length > 0)
-  {
-    var selector = "";
-
-    for (var i = 0; i < elt.classList.length; i++)
-      selector += "." + escapeCSS(elt.classList[i]);
-
-    addSelector(selector);
-  }
-
-  var urls = getURLsFromElement(elt);
-  for (var i = 0; i < urls.length; i++)
-  {
-    var url = urls[i];
-
-    if (/^https?:/i.test(url))
-    {
-      var filter = url.replace(/^[\w\-]+:\/+(?:www\.)?/, "||");
-
-      if (clickHideFilters.indexOf(filter) == -1)
-        clickHideFilters.push(filter);
-
-      continue;
-    }
-
-    if (url == elt.src)
-      addSelector(escapeCSS(elt.localName) + '[src=' + quote(elt.getAttribute("src")) + ']');
-  }
-
-  // as last resort, create a filter based on inline styles
-  if (clickHideFilters.length == 0)
-  {
-    var style = getOriginalStyle(elt);
-    if (style)
-      addSelector(escapeCSS(elt.localName) + '[style=' + quote(style) + ']');
-  }
-
-  // Show popup
-  clickHide_showDialog(e.clientX, e.clientY, clickHideFilters);
-
-  // Highlight the elements specified by selector in yellow
-  if (selectorList.length > 0)
-    highlightElements(selectorList.join(","));
-  // Now, actually highlight the element the user clicked on in red
-  highlightElement(currentElement, "#fd1708", "#f6a1b5");
+    // Now, actually highlight the element the user clicked on in red
+    highlightElement(currentElement, "#fd1708", "#f6a1b5");
+  });
 
   // Make sure the browser doesn't handle this click
   e.preventDefault();
@@ -692,9 +748,14 @@
       case "clickhide-new-filter":
         if(lastRightClickEvent)
         {
-          clickHide_activated = true;
-          currentElement = addElementOverlay(lastRightClickEvent.target);
-          clickHide_mouseClick(lastRightClickEvent);
+          var event = lastRightClickEvent;
+
+          addElementOverlay(event.target, function(overlay)
+          {
+            clickHide_activated = true;
+            currentElement = overlay;
+            clickHide_mouseClick(event);
+          });
         }
         break;
       case "clickhide-init":