third_party/blink/renderer/core/style/style_image.h - chromium/src - Git at Google

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 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 THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_STYLE_IMAGE_H_
 #define THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_STYLE_IMAGE_H_

 #include "third_party/blink/renderer/core/core_export.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
 #include "third_party/blink/renderer/platform/wtf/forward.h"

 namespace blink {

 class CSSValue;
 class FloatSize;
 class Image;
 class ImageResourceContent;
 class LayoutSize;
 class SVGImage;
 class Document;
 class ComputedStyle;
 class ImageResourceObserver;

 typedef void* WrappedImagePtr;

 // This class represents a CSS <image> value in ComputedStyle. The underlying
 // object can be an image, a gradient or anything else defined as an <image>
 // value.
 class CORE_EXPORT StyleImage : public GarbageCollectedFinalized<StyleImage> {
  public:
   virtual ~StyleImage() = default;

   bool operator==(const StyleImage& other) const {
     return Data() == other.Data();
   }

   // Returns a CSSValue representing the origin <image> value. May not be the
   // actual CSSValue from which this StyleImage was originally created if the
   // CSSValue can be recreated easily (like for StyleFetchedImage) and does not
   // contain per-client state (like for StyleGeneratedImage.)
   virtual CSSValue* CssValue() const = 0;

   // Returns a CSSValue suitable for using as part of a computed style
   // value. This often means that any URLs have been made absolute, and similar
   // actions described by a "Computed value" in the relevant specification.
   virtual CSSValue* ComputedCSSValue() const = 0;

   // An Image can be provided for rendering by GetImage.
   virtual bool CanRender() const { return true; }

   // All underlying resources this <image> references has finished loading.
   virtual bool IsLoaded() const { return true; }

   // Any underlying resources this <image> references failed to load.
   virtual bool ErrorOccurred() const { return false; }

   // Determine the concrete object size of this <image>, scaled by multiplier,
   // using the specified default object size. Return value as a FloatSize
   // because we want integer sizes to remain integers when zoomed and then
   // unzoomed. That is, (size * multiplier) / multiplier == size.
   //
   // The default object size is context dependent, see for instance the
   // "Examples of CSS Object Sizing" section of the CSS images specification.
   // https://drafts.csswg.org/css-images/#sizing.
   //
   // The |default_object_size| is assumed to be in the effective zoom level
   // given by multiplier, i.e. if multiplier is 1 the |default_object_size| is
   // not zoomed. Note that the |default_object_size| has already been snapped
   // to LayoutUnit resolution because it represents the target painted size of
   // a container.
   virtual FloatSize ImageSize(const Document&,
                               float multiplier,
                               const LayoutSize& default_object_size) const = 0;

   // The <image> does not have any intrinsic dimensions.
   virtual bool ImageHasRelativeSize() const = 0;

   // The <image> may depend on dimensions from the context the image is used in
   // (the "container".)
   virtual bool UsesImageContainerSize() const = 0;

   virtual void AddClient(ImageResourceObserver*) = 0;
   virtual void RemoveClient(ImageResourceObserver*) = 0;

   // Retrieve an Image representation for painting this <image>, at a particular
   // target size. Most often, the target size is a concrete object size
   // into which the image will be painted. But for background images the
   // target size is the area to be filled with a single copy of the image,
   // and can have a variety of relationships to the container's size. Hence
   // it requires float resolution.
   //
   // Note that the |target_size| is in the effective zoom level of the
   // computed style, i.e if the style has an effective zoom level of 1.0 the
   // |target_size| is not zoomed.
   virtual scoped_refptr<Image> GetImage(const ImageResourceObserver&,
                                         const Document&,
                                         const ComputedStyle&,
                                         const FloatSize& target_size) const = 0;

   // Opaque handle representing the underlying value of this <image>.
   virtual WrappedImagePtr Data() const = 0;

   // A scale factor indicating how many physical pixels in an image represent a
   // logical (CSS) pixel.
   virtual float ImageScaleFactor() const { return 1; }

   // Returns true if it can be determined that this <image> will always provide
   // an opaque Image.
   virtual bool KnownToBeOpaque(const Document&, const ComputedStyle&) const = 0;

   // If this <image> is intrinsically an image resource, this returns its
   // underlying ImageResourceContent, or otherwise nullptr.
   virtual ImageResourceContent* CachedImage() const { return nullptr; }

   ALWAYS_INLINE bool IsImageResource() const { return is_image_resource_; }
   ALWAYS_INLINE bool IsPendingImage() const { return is_pending_image_; }
   ALWAYS_INLINE bool IsGeneratedImage() const { return is_generated_image_; }
   ALWAYS_INLINE bool IsImageResourceSet() const {
     return is_image_resource_set_;
   }
   ALWAYS_INLINE bool IsPaintImage() const { return is_paint_image_; }

   virtual void Trace(blink::Visitor* visitor) {}

  protected:
   StyleImage()
       : is_image_resource_(false),
         is_pending_image_(false),
         is_generated_image_(false),
         is_image_resource_set_(false),
         is_paint_image_(false) {}
   bool is_image_resource_ : 1;
   bool is_pending_image_ : 1;
   bool is_generated_image_ : 1;
   bool is_image_resource_set_ : 1;
   bool is_paint_image_ : 1;

   FloatSize ApplyZoom(const FloatSize&, float multiplier) const;
   FloatSize ImageSizeForSVGImage(SVGImage*,
                                  float multiplier,
                                  const LayoutSize& default_object_size) const;
 };

 #define DEFINE_STYLE_IMAGE_TYPE_CASTS(thisType, function)                   \
   DEFINE_TYPE_CASTS(thisType, StyleImage, styleImage, styleImage->function, \
                     styleImage.function);                                   \
   inline thisType* To##thisType(const Member<StyleImage>& styleImage) {     \
     return To##thisType(styleImage.Get());                                  \
   }                                                                         \
   typedef int NeedsSemiColonAfterDefineStyleImageTypeCasts

 }  // namespace blink
 #endif
	/*
	* Copyright (C) 2000 Lars Knoll (knoll@kde.org)
	* (C) 2000 Antti Koivisto (koivisto@kde.org)
	* (C) 2000 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2003, 2005, 2006, 2007, 2008 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 THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_STYLE_IMAGE_H_
	#define THIRD_PARTY_BLINK_RENDERER_CORE_STYLE_STYLE_IMAGE_H_

	#include "third_party/blink/renderer/core/core_export.h"
	#include "third_party/blink/renderer/platform/heap/handle.h"
	#include "third_party/blink/renderer/platform/wtf/forward.h"

	namespace blink {

	class CSSValue;
	class FloatSize;
	class Image;
	class ImageResourceContent;
	class LayoutSize;
	class SVGImage;
	class Document;
	class ComputedStyle;
	class ImageResourceObserver;

	typedef void* WrappedImagePtr;

	// This class represents a CSS <image> value in ComputedStyle. The underlying
	// object can be an image, a gradient or anything else defined as an <image>
	// value.
	class CORE_EXPORT StyleImage : public GarbageCollectedFinalized<StyleImage> {
	public:
	virtual ~StyleImage() = default;

	bool operator==(const StyleImage& other) const {
	return Data() == other.Data();
	}

	// Returns a CSSValue representing the origin <image> value. May not be the
	// actual CSSValue from which this StyleImage was originally created if the
	// CSSValue can be recreated easily (like for StyleFetchedImage) and does not
	// contain per-client state (like for StyleGeneratedImage.)
	virtual CSSValue* CssValue() const = 0;

	// Returns a CSSValue suitable for using as part of a computed style
	// value. This often means that any URLs have been made absolute, and similar
	// actions described by a "Computed value" in the relevant specification.
	virtual CSSValue* ComputedCSSValue() const = 0;

	// An Image can be provided for rendering by GetImage.
	virtual bool CanRender() const { return true; }

	// All underlying resources this <image> references has finished loading.
	virtual bool IsLoaded() const { return true; }

	// Any underlying resources this <image> references failed to load.
	virtual bool ErrorOccurred() const { return false; }

	// Determine the concrete object size of this <image>, scaled by multiplier,
	// using the specified default object size. Return value as a FloatSize
	// because we want integer sizes to remain integers when zoomed and then
	// unzoomed. That is, (size * multiplier) / multiplier == size.
	//
	// The default object size is context dependent, see for instance the
	// "Examples of CSS Object Sizing" section of the CSS images specification.
	// https://drafts.csswg.org/css-images/#sizing.
	//
	// The \|default_object_size\| is assumed to be in the effective zoom level
	// given by multiplier, i.e. if multiplier is 1 the \|default_object_size\| is
	// not zoomed. Note that the \|default_object_size\| has already been snapped
	// to LayoutUnit resolution because it represents the target painted size of
	// a container.
	virtual FloatSize ImageSize(const Document&,
	float multiplier,
	const LayoutSize& default_object_size) const = 0;

	// The <image> does not have any intrinsic dimensions.
	virtual bool ImageHasRelativeSize() const = 0;

	// The <image> may depend on dimensions from the context the image is used in
	// (the "container".)
	virtual bool UsesImageContainerSize() const = 0;

	virtual void AddClient(ImageResourceObserver*) = 0;
	virtual void RemoveClient(ImageResourceObserver*) = 0;

	// Retrieve an Image representation for painting this <image>, at a particular
	// target size. Most often, the target size is a concrete object size
	// into which the image will be painted. But for background images the
	// target size is the area to be filled with a single copy of the image,
	// and can have a variety of relationships to the container's size. Hence
	// it requires float resolution.
	//
	// Note that the \|target_size\| is in the effective zoom level of the
	// computed style, i.e if the style has an effective zoom level of 1.0 the
	// \|target_size\| is not zoomed.
	virtual scoped_refptr<Image> GetImage(const ImageResourceObserver&,
	const Document&,
	const ComputedStyle&,
	const FloatSize& target_size) const = 0;

	// Opaque handle representing the underlying value of this <image>.
	virtual WrappedImagePtr Data() const = 0;

	// A scale factor indicating how many physical pixels in an image represent a
	// logical (CSS) pixel.
	virtual float ImageScaleFactor() const { return 1; }

	// Returns true if it can be determined that this <image> will always provide
	// an opaque Image.
	virtual bool KnownToBeOpaque(const Document&, const ComputedStyle&) const = 0;

	// If this <image> is intrinsically an image resource, this returns its
	// underlying ImageResourceContent, or otherwise nullptr.
	virtual ImageResourceContent* CachedImage() const { return nullptr; }

	ALWAYS_INLINE bool IsImageResource() const { return is_image_resource_; }
	ALWAYS_INLINE bool IsPendingImage() const { return is_pending_image_; }
	ALWAYS_INLINE bool IsGeneratedImage() const { return is_generated_image_; }
	ALWAYS_INLINE bool IsImageResourceSet() const {
	return is_image_resource_set_;
	}
	ALWAYS_INLINE bool IsPaintImage() const { return is_paint_image_; }

	virtual void Trace(blink::Visitor* visitor) {}

	protected:
	StyleImage()
	: is_image_resource_(false),
	is_pending_image_(false),
	is_generated_image_(false),
	is_image_resource_set_(false),
	is_paint_image_(false) {}
	bool is_image_resource_ : 1;
	bool is_pending_image_ : 1;
	bool is_generated_image_ : 1;
	bool is_image_resource_set_ : 1;
	bool is_paint_image_ : 1;

	FloatSize ApplyZoom(const FloatSize&, float multiplier) const;
	FloatSize ImageSizeForSVGImage(SVGImage*,
	float multiplier,
	const LayoutSize& default_object_size) const;
	};

	#define DEFINE_STYLE_IMAGE_TYPE_CASTS(thisType, function) \
	DEFINE_TYPE_CASTS(thisType, StyleImage, styleImage, styleImage->function, \
	styleImage.function); \
	inline thisType* To##thisType(const Member<StyleImage>& styleImage) { \
	return To##thisType(styleImage.Get()); \
	} \
	typedef int NeedsSemiColonAfterDefineStyleImageTypeCasts

	} // namespace blink
	#endif