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
@@ -193,24 +193,6 @@
   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(element.getAttribute("style")))
-    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
@@ -321,13 +303,17 @@
     clickHide_deactivate();
 
   // Add overlays for blockable elements that don't emit mouse events that they can still be selected
-  var elts = document.querySelectorAll('object,embed,iframe');
-  for(var i=0; i<elts.length; i++)
-  {
-    var element = elts[i];
-    if (isBlockable(element))
-      addElementOverlay(element);
-  }
+  [].forEach.call(
+    document.querySelectorAll('object,embed,iframe'),
+    function(element)
+    {
+      getFiltersForElement(element, function(filters)
+      {
+        if (filters.length > 0)
+          addElementOverlay(element);
+      });
+    }
+  );
 
   clickHide_activated = true;
   document.addEventListener("mouseover", clickHide_mouseOver, true);
@@ -388,31 +374,57 @@
   clickHide_mouseClick(ev);
 }
 
+function getBlockableElementOrAncestor(element, callback)
+{
+  if (element && element != document.documentElement &&
+                 element != document.body)
+  {
+    if (element instanceof HTMLElement)
+    {
+      getFiltersForElement(element, function(filters)
+      {
+        if (filters.length > 0)
+          callback(element);
+        else
+          getBlockableElementOrAncestor(element.parentElement, callback);
+      });
+    }
+    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);
@@ -450,6 +462,7 @@
       style: element.getAttribute("style"),
       classes: [].slice.call(element.classList),
       urls: getURLsFromElement(element),
+      mediatype: typeMap[element.localName],
       baseURL: document.location.href
     },
     function(response)