third_party/WebKit/Source/core/fetch/ImageResource.h

/*
    Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
    Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
    Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
    Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#ifndef ImageResource_h
#define ImageResource_h

#include "core/CoreExport.h"
#include "core/fetch/MultipartImageResourceParser.h"
#include "core/fetch/Resource.h"
#include "platform/geometry/IntRect.h"
#include "platform/geometry/IntSizeHash.h"
#include "platform/geometry/LayoutSize.h"
#include "platform/graphics/ImageObserver.h"
#include "platform/graphics/ImageOrientation.h"
#include "wtf/HashMap.h"
#include <memory>

namespace blink {

class FetchRequest;
class FloatSize;
class ImageResourceObserver;
class MemoryCache;
class ResourceClient;
class ResourceFetcher;
class SecurityOrigin;

// ImageResource class represents an image type resource.
//
// As for the lifetimes of m_image and m_data, see this document:
// https://docs.google.com/document/d/1v0yTAZ6wkqX2U_M6BNIGUJpM1s0TIw1VsqpxoL7aciY/edit?usp=sharing
class CORE_EXPORT ImageResource final
    : public Resource,
      public ImageObserver,
      public MultipartImageResourceParser::Client {
  friend class MemoryCache;
  USING_GARBAGE_COLLECTED_MIXIN(ImageResource);

 public:
  using ClientType = ResourceClient;

  static ImageResource* fetch(FetchRequest&, ResourceFetcher*);

  static ImageResource* create(blink::Image* image) {
    return new ImageResource(image, ResourceLoaderOptions());
  }

  static ImageResource* create(const ResourceRequest& request) {
    return new ImageResource(request, ResourceLoaderOptions());
  }

  ~ImageResource() override;

  blink::Image*
  getImage();  // Returns the nullImage() if the image is not available yet.
  bool hasImage() const { return m_image.get(); }

  static std::pair<blink::Image*, float> brokenImage(
      float deviceScaleFactor);  // Returns an image and the image's resolution
                                 // scale factor.
  bool willPaintBrokenImage() const;

  bool usesImageContainerSize() const;
  bool imageHasRelativeSize() const;
  // The device pixel ratio we got from the server for this image, or 1.0.
  float devicePixelRatioHeaderValue() const {
    return m_devicePixelRatioHeaderValue;
  }
  bool hasDevicePixelRatioHeaderValue() const {
    return m_hasDevicePixelRatioHeaderValue;
  }

  enum SizeType {
    // Report the intrinsic size.
    IntrinsicSize,

    // Report the intrinsic size corrected to account for image density.
    IntrinsicCorrectedToDPR,
  };

  // This method takes a zoom multiplier that can be used to increase the
  // natural size of the image by the zoom.
  LayoutSize imageSize(
      RespectImageOrientationEnum shouldRespectImageOrientation,
      float multiplier,
      SizeType = IntrinsicSize);

  bool isAccessAllowed(SecurityOrigin*);

  void updateImageAnimationPolicy();

  // If this ImageResource has the Lo-Fi response headers, reload it with the
  // Lo-Fi state set to off and bypassing the cache.
  void reloadIfLoFi(ResourceFetcher*);

  void didAddClient(ResourceClient*) override;

  void addObserver(ImageResourceObserver*);
  void removeObserver(ImageResourceObserver*);

  ResourcePriority priorityFromObservers() override;

  void allClientsAndObserversRemoved() override;

  PassRefPtr<const SharedBuffer> resourceBuffer() const override;
  void appendData(const char*, size_t) override;
  void error(const ResourceError&) override;
  void responseReceived(const ResourceResponse&,
                        std::unique_ptr<WebDataConsumerHandle>) override;
  void finish(double finishTime = 0.0) override;

  void onMemoryDump(WebMemoryDumpLevelOfDetail,
                    WebProcessMemoryDump*) const override;

  // For compatibility, images keep loading even if there are HTTP errors.
  bool shouldIgnoreHTTPStatusCodeErrors() const override { return true; }

  bool isImage() const override { return true; }

  // ImageObserver
  void decodedSizeChangedTo(const blink::Image*, size_t newSize) override;
  void didDraw(const blink::Image*) override;

  bool shouldPauseAnimation(const blink::Image*) override;
  void animationAdvanced(const blink::Image*) override;
  void changedInRect(const blink::Image*, const IntRect&) override;

  // MultipartImageResourceParser::Client
  void onePartInMultipartReceived(const ResourceResponse&) final;
  void multipartDataReceived(const char*, size_t) final;

  DECLARE_VIRTUAL_TRACE();

 private:
  explicit ImageResource(blink::Image*, const ResourceLoaderOptions&);

  enum class MultipartParsingState : uint8_t {
    WaitingForFirstPart,
    ParsingFirstPart,
    FinishedParsingFirstPart,
  };

  class ImageResourceFactory : public ResourceFactory {
   public:
    ImageResourceFactory() : ResourceFactory(Resource::Image) {}

    Resource* create(const ResourceRequest& request,
                     const ResourceLoaderOptions& options,
                     const String&) const override {
      return new ImageResource(request, options);
    }
  };
  ImageResource(const ResourceRequest&, const ResourceLoaderOptions&);

  bool hasClientsOrObservers() const override {
    return Resource::hasClientsOrObservers() || !m_observers.isEmpty() ||
           !m_finishedObservers.isEmpty();
  }
  void clear();

  void createImage();
  void updateImage(bool allDataReceived);
  void updateImageAndClearBuffer();
  void clearImage();
  // If not null, changeRect is the changed part of the image.
  void notifyObservers(const IntRect* changeRect = nullptr);

  void ensureImage();

  void checkNotify() override;
  void notifyObserversInternal(MarkFinishedOption);
  void markObserverFinished(ImageResourceObserver*);

  void doResetAnimation();

  void destroyDecodedDataIfPossible() override;
  void destroyDecodedDataForFailedRevalidation() override;

  float m_devicePixelRatioHeaderValue;

  Member<MultipartImageResourceParser> m_multipartParser;
  RefPtr<blink::Image> m_image;
  MultipartParsingState m_multipartParsingState =
      MultipartParsingState::WaitingForFirstPart;
  bool m_hasDevicePixelRatioHeaderValue;
  HashCountedSet<ImageResourceObserver*> m_observers;
  HashCountedSet<ImageResourceObserver*> m_finishedObservers;
};

DEFINE_RESOURCE_TYPE_CASTS(Image);

}  // namespace blink

#endif