Set width and height attributes for <img> if image is loaded from srcset

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 22 matching lines @@
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameSerializer.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.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/loader/DocumentLoader.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"
@@ skipping 31 matching lines @@
       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:
+  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) {
   // 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
@@ skipping 82 matching lines @@
              WebFrameSerializerCacheControlPolicy::
                  SkipAnyFrameOrResourceMarkedNoStore &&
          hasCacheControlNoStoreHeader ==
              FrameSerializer::HasCacheControlNoStoreHeader;
 }
 
 Vector<Attribute> MHTMLFrameSerializerDelegate::getCustomAttributes(
     const Element& element) {
   Vector<Attribute> attributes;
 
-  // Disable all form elements in MTHML to tell the user that the form cannot be
-  // worked on. MHTML is loaded in full sandboxing mode which disable the form
-  // submission and script execution.
-  if (element.isFormControlElement() &&
-      !element.fastHasAttribute(HTMLNames::disabledAttr)) {
-    Attribute disabledAttribute(HTMLNames::disabledAttr, "");
-    attributes.push_back(disabledAttribute);
+  if (isHTMLImageElement(element)) {
+    getCustomAttributesForImageElement(toHTMLImageElement(element),
+                                       &attributes);
+  } else if (element.isFormControlElement()) {
+    getCustomAttributesForFormControlElement(element, &attributes);
   }
 
   return attributes;
 }
 
+void MHTMLFrameSerializerDelegate::getCustomAttributesForImageElement(
+    const HTMLImageElement& element,
+    Vector<Attribute>* attributes) {
+  // Currently only the value of src is pulled into the archive and the srcset
+  // attribute is ignored (see shouldIgnoreAttribute() above). If the device
+  // has a higher DPR, a different image from srcsrt could be loaded instead.

[tkent, 2017/01/11 02:15:32]

srcsrt -> srcset

[jianli, 2017/01/11 23:12:30]

Done.

+  // When this occurs, we should provide the rendering width and height for
+  // <img> element if not set.
+
+  // The image should be loaded and participate the layout.
+  ImageResourceContent* image = element.cachedImage();
+  if (!image || !image->hasImage() || image->errorOccurred() ||
+      !element.layoutObject()) {
+    return;
+  }
+
+  // The width and height attributes should not be set.
+  if (element.fastHasAttribute(HTMLNames::widthAttr) ||
+      element.fastHasAttribute(HTMLNames::heightAttr)) {
+    return;
+  }
+
+  // Check if different image is loaded. naturalWidth/naturalHeight will return
+  // the image size adjusted with current DPR.
+  if (((int)element.naturalWidth()) == image->getImage()->width() &&
+      ((int)element.naturalHeight()) == image->getImage()->height()) {
+    return;
+  }
+
+  Attribute widthAttribute(HTMLNames::widthAttr,
+                           AtomicString::number(element.layoutBoxWidth()));
+  attributes->push_back(widthAttribute);
+  Attribute heightAttribute(HTMLNames::heightAttr,
+                            AtomicString::number(element.layoutBoxHeight()));
+  attributes->push_back(heightAttribute);
+}
+
+void MHTMLFrameSerializerDelegate::getCustomAttributesForFormControlElement(
+    const Element& element,
+    Vector<Attribute>* attributes) {
+  // Disable all form elements in MTHML to tell the user that the form cannot be
+  // worked on. MHTML is loaded in full sandboxing mode which disable the form
+  // submission and script execution.
+  if (element.fastHasAttribute(HTMLNames::disabledAttr))
+    return;
+  Attribute disabledAttribute(HTMLNames::disabledAttr, "");
+  attributes->push_back(disabledAttribute);
+}
+
 bool cacheControlNoStoreHeaderPresent(
     const WebLocalFrameImpl& webLocalFrameImpl) {
   const ResourceResponse& response =
       webLocalFrameImpl.dataSource()->response().toResourceResponse();
   if (response.cacheControlContainsNoStore())
     return true;
 
   const ResourceRequest& request =
       webLocalFrameImpl.dataSource()->getRequest().toResourceRequest();
   return request.cacheControlContainsNoStore();
@@ skipping 145 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