third_party/WebKit/Source/core/frame/FrameSerializer.h

/*
 * Copyright (C) 2011 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
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promo te products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FrameSerializer_h
#define FrameSerializer_h

#include "core/CoreExport.h"
#include "platform/heap/Handle.h"
#include "platform/weborigin/KURL.h"
#include "platform/weborigin/KURLHash.h"
#include "wtf/Forward.h"
#include "wtf/HashSet.h"
#include "wtf/Vector.h"

namespace blink {

class Attribute;
class CSSRule;
class CSSStyleSheet;
class CSSValue;
class Document;
class Element;
class FontResource;
class ImageResource;
class LocalFrame;
class Node;
class LayoutObject;
class Resource;
class SharedBuffer;
class StylePropertySet;

struct SerializedResource;

// This class is used to serialize frame's contents back to text (typically
// HTML).  It serializes frame's document and resources such as images and CSS
// stylesheets.
class CORE_EXPORT FrameSerializer final {
  STACK_ALLOCATED();

 public:
  class Delegate {
   public:
    // Controls whether HTML serialization should skip the given attribute.
    virtual bool shouldIgnoreAttribute(const Attribute&) { return false; }

    // Method allowing the Delegate control which URLs are written into the
    // generated html document.
    //
    // When URL of the element needs to be rewritten, this method should
    // return true and populate |rewrittenLink| with a desired value of the
    // html attribute value to be used in place of the original link.
    // (i.e. in place of img.src or iframe.src or object.data).
    //
    // If no link rewriting is desired, this method should return false.
    virtual bool rewriteLink(const Element&, String& rewrittenLink) {
      return false;
    }

    // Tells whether to skip serialization of a subresource or CSSStyleSheet
    // with a given URI. Used to deduplicate resources across multiple frames.
    virtual bool shouldSkipResourceWithURL(const KURL&) { return false; }

    // Tells whether to skip serialization of a subresource.
    virtual bool shouldSkipResource(const Resource&) { return false; }
  };

  // Constructs a serializer that will write output to the given vector of
  // SerializedResources and uses the Delegate for controlling some
  // serialization aspects.  Callers need to ensure that both arguments stay
  // alive until the FrameSerializer gets destroyed.
  FrameSerializer(Vector<SerializedResource>&, Delegate&);

  // Initiates the serialization of the frame. All serialized content and
  // retrieved resources are added to the Vector passed to the constructor.
  // The first resource in that vector is the frame's serialized content.
  // Subsequent resources are images, css, etc.
  void serializeFrame(const LocalFrame&);

  static String markOfTheWebDeclaration(const KURL&);

 private:
  // Serializes the stylesheet back to text and adds it to the resources if URL
  // is not-empty.  It also adds any resources included in that stylesheet
  // (including any imported stylesheets and their own resources).
  void serializeCSSStyleSheet(CSSStyleSheet&, const KURL&);

  // Serializes the css rule (including any imported stylesheets), adding
  // referenced resources.
  void serializeCSSRule(CSSRule*);

  bool shouldAddURL(const KURL&);

  void addToResources(const Resource&,
                      PassRefPtr<const SharedBuffer>,
                      const KURL&);
  void addImageToResources(ImageResource*, const KURL&);
  void addFontToResources(FontResource*);

  void retrieveResourcesForProperties(const StylePropertySet*, Document&);
  void retrieveResourcesForCSSValue(const CSSValue&, Document&);

  Vector<SerializedResource>* m_resources;
  HashSet<KURL> m_resourceURLs;

  bool m_isSerializingCss;

  Delegate& m_delegate;
};

}  // namespace blink

#endif  // FrameSerializer_h