third_party/WebKit/Source/core/style/StyleFetchedImageSet.h

/*
 * Copyright (C) 2012 Apple 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 */

#ifndef StyleFetchedImageSet_h
#define StyleFetchedImageSet_h

#include "core/fetch/ResourceClient.h"
#include "core/style/StyleImage.h"
#include "platform/geometry/LayoutSize.h"
#include "platform/weborigin/KURL.h"

namespace blink {

class ImageResource;
class CSSImageSetValue;

// This class keeps one cached image and has access to a set of alternatives.

class StyleFetchedImageSet final : public StyleImage, private ResourceClient {
  USING_PRE_FINALIZER(StyleFetchedImageSet, dispose);
  USING_GARBAGE_COLLECTED_MIXIN(StyleFetchedImageSet);

 public:
  static StyleFetchedImageSet* create(ImageResource* image,
                                      float imageScaleFactor,
                                      CSSImageSetValue* value,
                                      const KURL& url) {
    return new StyleFetchedImageSet(image, imageScaleFactor, value, url);
  }
  ~StyleFetchedImageSet() override;

  CSSValue* cssValue() const override;
  CSSValue* computedCSSValue() const override;

  // FIXME: This is used by StyleImage for equals comparison, but this
  // implementation only looks at the image from the set that we have loaded.
  // I'm not sure if that is meaningful enough or not.
  WrappedImagePtr data() const override;

  bool canRender() const override;
  bool isLoaded() const override;
  bool errorOccurred() const override;
  LayoutSize imageSize(const LayoutObject&,
                       float multiplier,
                       const LayoutSize& defaultObjectSize) const override;
  bool imageHasRelativeSize() const override;
  bool usesImageContainerSize() const override;
  void addClient(LayoutObject*) override;
  void removeClient(LayoutObject*) override;
  PassRefPtr<Image> image(const LayoutObject&,
                          const IntSize&,
                          float) const override;
  float imageScaleFactor() const override { return m_imageScaleFactor; }
  bool knownToBeOpaque(const LayoutObject&) const override;
  ImageResource* cachedImage() const override;

  DECLARE_VIRTUAL_TRACE();

 private:
  StyleFetchedImageSet(ImageResource*,
                       float imageScaleFactor,
                       CSSImageSetValue*,
                       const KURL&);

  void dispose();

  String debugName() const override { return "StyleFetchedImageSet"; }

  Member<ImageResource> m_bestFitImage;
  float m_imageScaleFactor;

  Member<CSSImageSetValue> m_imageSetValue;  // Not retained; it owns us.
  const KURL m_url;
};

DEFINE_STYLE_IMAGE_TYPE_CASTS(StyleFetchedImageSet, isImageResourceSet());

}  // namespace blink

#endif  // StyleFetchedImageSet_h