gecko-dev/image/ImageOps.h

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5.4 KiB
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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_ImageOps_h
#define mozilla_image_ImageOps_h
#include "nsCOMPtr.h"
#include "nsRect.h"
#include "ImageMetadata.h"
class gfxDrawable;
class imgIContainer;
class nsIInputStream;
namespace mozilla {
namespace gfx {
class SourceSurface;
}
namespace image {
class Image;
struct Orientation;
class SourceBuffer;
class ImageOps
{
public:
class ImageBuffer {
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ImageOps::ImageBuffer);
protected:
friend class ImageOps;
ImageBuffer() { }
virtual ~ImageBuffer() { }
virtual already_AddRefed<SourceBuffer> GetSourceBuffer() const = 0;
};
/**
* Creates a version of an existing image which does not animate and is frozen
* at the first frame.
*
* @param aImage The existing image.
*/
static already_AddRefed<Image> Freeze(Image* aImage);
static already_AddRefed<imgIContainer> Freeze(imgIContainer* aImage);
/**
* Creates a clipped version of an existing image. Animation is unaffected.
*
* @param aImage The existing image.
* @param aClip The rectangle to clip the image against.
* @param aSVGViewportSize The specific viewort size of aImage. Unless aImage
* is a vector image without intrinsic size, this
* argument should be pass as Nothing().
*/
static already_AddRefed<Image> Clip(Image* aImage, nsIntRect aClip,
const Maybe<nsSize>& aSVGViewportSize =
Nothing());
static already_AddRefed<imgIContainer> Clip(imgIContainer* aImage,
nsIntRect aClip,
const Maybe<nsSize>& aSVGViewportSize =
Nothing());
/**
* Creates a version of an existing image which is rotated and/or flipped to
* the specified orientation.
*
* @param aImage The existing image.
* @param aOrientation The desired orientation.
*/
static already_AddRefed<Image> Orient(Image* aImage,
Orientation aOrientation);
static already_AddRefed<imgIContainer> Orient(imgIContainer* aImage,
Orientation aOrientation);
/**
* Creates an image from a gfxDrawable.
*
* @param aDrawable The gfxDrawable.
*/
static already_AddRefed<imgIContainer>
CreateFromDrawable(gfxDrawable* aDrawable);
/**
* Create a buffer to be used with DecodeMetadata and DecodeToSurface. Reusing
* an ImageBuffer representing the given input stream is more efficient if one
* has multiple Decode* calls to make on that stream.
*
* @param aInputStream An input stream containing an encoded image. The
* ownership is taken.
* @return An image buffer derived from the input stream.
*/
static already_AddRefed<ImageBuffer>
CreateImageBuffer(already_AddRefed<nsIInputStream> aInputStream);
/**
* Decodes an image's metadata from an nsIInputStream into the given
* structure. This function may be called off-main-thread.
*
* @param aInputStream An input stream containing an encoded image. Ownership
* is taken.
* @param aMimeType The MIME type of the image.
* @param aMetadata Where the image metadata is stored upon success.
* @return The status of the operation.
*/
static nsresult
DecodeMetadata(already_AddRefed<nsIInputStream> aInputStream,
const nsACString& aMimeType,
ImageMetadata& aMetadata);
/**
* Same as above but takes an ImageBuffer instead of nsIInputStream.
*/
static nsresult
DecodeMetadata(ImageBuffer* aBuffer,
const nsACString& aMimeType,
ImageMetadata& aMetadata);
/**
* Decodes an image from an nsIInputStream directly into a SourceSurface,
* without ever creating an Image or imgIContainer (which are mostly
* main-thread-only). That means that this function may be called
* off-main-thread.
*
* @param aInputStream An input stream containing an encoded image. The
* ownership is taken.
* @param aMimeType The MIME type of the image.
* @param aFlags Flags of the imgIContainer::FLAG_DECODE_* variety.
* @return A SourceSurface containing the first frame of the image at its
* intrinsic size, or nullptr if the image cannot be decoded.
*/
static already_AddRefed<gfx::SourceSurface>
DecodeToSurface(already_AddRefed<nsIInputStream> aInputStream,
const nsACString& aMimeType,
uint32_t aFlags,
const Maybe<gfx::IntSize>& aSize = Nothing());
/**
* Same as above but takes an ImageBuffer instead of nsIInputStream.
*/
static already_AddRefed<gfx::SourceSurface>
DecodeToSurface(ImageBuffer* aBuffer,
const nsACString& aMimeType,
uint32_t aFlags,
const Maybe<gfx::IntSize>& aSize = Nothing());
private:
class ImageBufferImpl;
// This is a static utility class, so disallow instantiation.
virtual ~ImageOps() = 0;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_ImageOps_h