Remove popup overlay from MHTML when requested

third_party/WebKit/Source/web/WebFrameSerializer.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "public/web/WebFrameSerializer.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/frame/Frame.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameSerializer.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
+#include "core/frame/VisualViewport.h"
 #include "core/html/HTMLAllCollection.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLTableElement.h"
+#include "core/layout/LayoutBox.h"
 #include "core/loader/DocumentLoader.h"
+#include "core/page/Page.h"
 #include "platform/Histogram.h"
 #include "platform/SerializedResource.h"
 #include "platform/SharedBuffer.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "platform/mhtml/MHTMLArchive.h"
 #include "platform/mhtml/MHTMLParser.h"
 #include "platform/network/ResourceRequest.h"
 #include "platform/network/ResourceResponse.h"
 #include "platform/weborigin/KURL.h"
 #include "public/platform/WebString.h"
@@ skipping 13 matching lines @@
 #include "wtf/HashMap.h"
 #include "wtf/HashSet.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/Vector.h"
 #include "wtf/text/StringConcatenate.h"
 
 namespace blink {
 
 namespace {
 
+const int kPopupOverlayZIndexThreshold = 50;
+
 class MHTMLFrameSerializerDelegate final : public FrameSerializer::Delegate {
   WTF_MAKE_NONCOPYABLE(MHTMLFrameSerializerDelegate);
 
  public:
   explicit MHTMLFrameSerializerDelegate(
       WebFrameSerializer::MHTMLPartsGenerationDelegate&);
   bool shouldIgnoreElement(const Element&) override;
   bool shouldIgnoreAttribute(const Element&, const Attribute&) override;
   bool rewriteLink(const Element&, String& rewrittenLink) override;
   bool shouldSkipResourceWithURL(const KURL&) override;
   bool shouldSkipResource(
       FrameSerializer::ResourceHasCacheControlNoStoreHeader) override;
   Vector<Attribute> getCustomAttributes(const Element&) override;
 
  private:
+  bool shouldIgnoreHiddenElement(const Element&);
+  bool shouldIgnorePopupOverlayElement(const Element&);
   void getCustomAttributesForImageElement(const HTMLImageElement&,
                                           Vector<Attribute>*);
   void getCustomAttributesForFormControlElement(const Element&,
                                                 Vector<Attribute>*);
 
   WebFrameSerializer::MHTMLPartsGenerationDelegate& m_webDelegate;
 };
 
 MHTMLFrameSerializerDelegate::MHTMLFrameSerializerDelegate(
     WebFrameSerializer::MHTMLPartsGenerationDelegate& webDelegate)
     : m_webDelegate(webDelegate) {}
 
 bool MHTMLFrameSerializerDelegate::shouldIgnoreElement(const Element& element) {
+  if (shouldIgnoreHiddenElement(element))
+    return true;
+  if (m_webDelegate.removePopupOverlay() &&
+      shouldIgnorePopupOverlayElement(element)) {
+    return true;
+  }
+  return false;
+}
+
+bool MHTMLFrameSerializerDelegate::shouldIgnoreHiddenElement(
+    const Element& element) {
   // Do not include elements that are are set to hidden without affecting layout
   // by the page. For those elements that are hidden by default, they will not
   // be excluded:
   // 1) All elements that are head or part of head, including head, meta, style,
   //    link and etc.
   // 2) Some specific elements in body: meta, datalist, option and etc.
   if (element.layoutObject())
     return false;
   if (isHTMLHeadElement(element) || isHTMLMetaElement(element) ||
       isHTMLDataListElement(element) || isHTMLOptionElement(element)) {
     return false;
   }
   Element* parent = element.parentElement();
   return parent && !isHTMLHeadElement(parent);
 }
 
+bool MHTMLFrameSerializerDelegate::shouldIgnorePopupOverlayElement(
+    const Element& element) {
+  // The element should be visible.
+  LayoutBox* box = element.layoutBox();
+  if (!box || box->style()->display() == EDisplay::None)

[dcheng, 2017/01/19 18:24:55]

Note that an element styled with display:none won't have a LayoutObject (and
thus no LayoutBox), so the second part of the || is unnecessary.

[jianli, 2017/01/19 23:55:22]

Done.

+    return false;
+
+  // The bounding box of the element should contain center point of the

[Pete Williamson, 2017/01/19 18:08:28]

FYI - I have seen some popups in EM pages that do not cover the center of the
window. Would we be better without this check?

Example URLs with this behavior: 
http://www.ndtv.com/tv-schedule?pfrom=home-topnavigation2016
https://www.icicibank.com/

Although the dialog box does not cover the center, they grey out the rest of the
window, so if they do that with a transparent window, it might cover the center,
this might be a good test for your code.

[jianli, 2017/01/19 23:55:22]

The 1st one is covered while the 2nd one is not handled. Will investigate and
enhance the popup removal in future patch. For now, we're covering most common
and safe scenario: popup appearing at the center

+  // viewport.
+  LocalDOMWindow* window = element.document().domWindow();

[dcheng, 2017/01/19 18:24:55]

Nit: DCHECK instead of guarding with if, since we shouldn't be serializing
detached frames.

[jianli, 2017/01/19 23:55:22]

Done.

+  if (!window)
+    return false;
+  LayoutPoint centerPoint(window->innerWidth() / 2, window->innerHeight() / 2);
+  if (!box->frameRect().contains(centerPoint))
+    return false;
+
+  // The z-index should be greater than the threshold.
+  if (box->style()->zIndex() < kPopupOverlayZIndexThreshold)
+    return false;
+
+  return true;
+}
+
 bool MHTMLFrameSerializerDelegate::shouldIgnoreAttribute(
     const Element& element,
     const Attribute& attribute) {
   // TODO(fgorski): Presence of srcset attribute causes MHTML to not display
   // images, as only the value of src is pulled into the archive. Discarding
   // srcset prevents the problem. Long term we should make sure to MHTML plays
   // nicely with srcset.
   if (attribute.localName() == HTMLNames::srcsetAttr)
     return true;
 
@@ skipping 282 matching lines @@
     const WebString& baseTarget) {
   // TODO(yosin) We should call |FrameSerializer::baseTagDeclarationOf()|.
   if (baseTarget.isEmpty())
     return String("<base href=\".\">");
   String baseString = "<base href=\".\" target=\"" +
                       static_cast<const String&>(baseTarget) + "\">";
   return baseString;
 }
 
 }  // namespace blink