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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 ImageEncoder_h
#define ImageEncoder_h
#include "imgIEncoder.h"
#include "nsError.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/HTMLCanvasElementBinding.h"
#include "mozilla/UniquePtr.h"
#include "nsSize.h"
class nsICanvasRenderingContextInternal;
namespace mozilla {
namespace layers {
class Image;
} // namespace layers
namespace dom {
class EncodeCompleteCallback;
class EncodingRunnable;
class OffscreenCanvasDisplayHelper;
class ImageEncoder {
public:
// Extracts data synchronously and gives you a stream containing the image
// represented by aContext. aType may change to "image/png" if we had to fall
// back to a PNG encoder. A return value of NS_OK implies successful data
// extraction. If there are any unrecognized custom parse options in
// aOptions, NS_ERROR_INVALID_ARG will be returned. When encountering this
// error it is usual to call this function again without any options at all.
static nsresult ExtractData(nsAString& aType, const nsAString& aOptions,
const nsIntSize aSize, bool aUsePlaceholder,
nsICanvasRenderingContextInternal* aContext,
OffscreenCanvasDisplayHelper* aOffscreenDisplay,
nsIInputStream** aStream);
// Extracts data asynchronously. aType may change to "image/png" if we had to
// fall back to a PNG encoder. aOptions are the options to be passed to the
// encoder and aUsingCustomOptions specifies whether custom parse options were
// used (i.e. by using -moz-parse-options). If there are any unrecognized
// custom parse options, we fall back to the default values for the encoder
// without any options at all. A return value of NS_OK only implies
// successful dispatching of the extraction step to the encoding thread.
// aEncodeCallback will be called on main thread when encoding process is
// success.
// Note: The callback has to set a valid parent for content for the generated
// Blob object.
static nsresult ExtractDataAsync(nsAString& aType, const nsAString& aOptions,
bool aUsingCustomOptions,
UniquePtr<uint8_t[]> aImageBuffer,
int32_t aFormat, const nsIntSize aSize,
bool aUsePlaceholder,
EncodeCompleteCallback* aEncodeCallback);
// Extract an Image asynchronously. Its function is same as ExtractDataAsync
// except for the parameters. aImage is the uncompressed data. aEncodeCallback
// will be called on main thread when encoding process is success.
// Note: The callback has to set a valid parent for content for the generated
// Blob object.
static nsresult ExtractDataFromLayersImageAsync(
nsAString& aType, const nsAString& aOptions, bool aUsingCustomOptions,
layers::Image* aImage, bool aUsePlaceholder,
EncodeCompleteCallback* aEncodeCallback);
// Gives you a stream containing the image represented by aImageBuffer.
// The format is given in aFormat, for example
// imgIEncoder::INPUT_FORMAT_HOSTARGB.
static nsresult GetInputStream(int32_t aWidth, int32_t aHeight,
uint8_t* aImageBuffer, int32_t aFormat,
imgIEncoder* aEncoder,
const nsAString& aEncoderOptions,
nsIInputStream** aStream);
private:
// When called asynchronously, aContext and aRenderer are null.
static nsresult ExtractDataInternal(
const nsAString& aType, const nsAString& aOptions, uint8_t* aImageBuffer,
int32_t aFormat, const nsIntSize aSize, bool aUsePlaceholder,
layers::Image* aImage, nsICanvasRenderingContextInternal* aContext,
OffscreenCanvasDisplayHelper* aOffscreenDisplay, nsIInputStream** aStream,
imgIEncoder* aEncoder);
// Creates and returns an encoder instance of the type specified in aType.
// aType may change to "image/png" if no instance of the original type could
// be created and we had to fall back to a PNG encoder. A null return value
// should be interpreted as NS_IMAGELIB_ERROR_NO_ENCODER and aType is
// undefined in this case.
static already_AddRefed<imgIEncoder> GetImageEncoder(nsAString& aType);
friend class EncodingRunnable;
friend class EncoderThreadPoolTerminator;
};
/**
* The callback interface of ExtractDataAsync and
* ExtractDataFromLayersImageAsync. ReceiveBlobImpl() is called on main thread
* when encoding is complete.
*/
class EncodeCompleteCallback {
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(EncodeCompleteCallback)
MOZ_CAN_RUN_SCRIPT
virtual nsresult ReceiveBlobImpl(already_AddRefed<BlobImpl> aBlobImpl) = 0;
// CanBeDeletedOnAnyThread is pure virtual, so that whoever extends this class
// needs to think how to handle cases like the owning DOM worker thread
// shutting down.
virtual bool CanBeDeletedOnAnyThread() = 0;
protected:
virtual ~EncodeCompleteCallback() = default;
};
} // namespace dom
} // namespace mozilla
#endif // ImageEncoder_h
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