chromium/ui/gfx/image/image_internal.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This holds internal declarations for the machinery of gfx::Image. These are
// only for the internal use of gfx::Image; do not use them elsewhere.

#ifndef UI_GFX_IMAGE_IMAGE_INTERNAL_H_
#define UI_GFX_IMAGE_IMAGE_INTERNAL_H_

#include <map>
#include <memory>

#include "base/memory/ref_counted.h"
#include "build/build_config.h"
#include "ui/gfx/image/image.h"

#if BUILDFLAG(IS_MAC)
#include <CoreGraphics/CoreGraphics.h>
#endif

namespace gfx::internal {

class ImageRepPNG;
class ImageRepSkia;
class ImageRepCocoa;
class ImageRepCocoaTouch;

// An ImageRep is the object that holds the backing memory for an Image. Each
// RepresentationType has an ImageRep subclass that is responsible for freeing
// the memory that the ImageRep holds. When an ImageRep is created, it expects
// to take ownership of the image, without having to retain it or increase its
// reference count.
class ImageRep { … };

// The Storage class acts similarly to the pixels in a SkBitmap: the Image
// class holds a refptr instance of Storage, which in turn holds all the
// ImageReps. This way, the Image can be cheaply copied.
//
// This class is deliberately not RefCountedThreadSafe. Making it so does not
// solve threading issues, as gfx::Image and its internal classes are
// themselves not threadsafe.
class ImageStorage : public base::RefCounted<ImageStorage> { … };

}  // namespace gfx::internal

#endif  // UI_GFX_IMAGE_IMAGE_INTERNAL_H_