1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/canvas/src/ImageEncoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,95 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef ImageEncoder_h
1.10 +#define ImageEncoder_h
1.11 +
1.12 +#include "imgIEncoder.h"
1.13 +#include "nsDOMFile.h"
1.14 +#include "nsError.h"
1.15 +#include "mozilla/dom/HTMLCanvasElementBinding.h"
1.16 +#include "nsLayoutUtils.h"
1.17 +#include "nsNetUtil.h"
1.18 +#include "nsSize.h"
1.19 +
1.20 +class nsICanvasRenderingContextInternal;
1.21 +
1.22 +namespace mozilla {
1.23 +namespace dom {
1.24 +
1.25 +class EncodingRunnable;
1.26 +
1.27 +class ImageEncoder
1.28 +{
1.29 +public:
1.30 + // Extracts data synchronously and gives you a stream containing the image
1.31 + // represented by aContext. aType may change to "image/png" if we had to fall
1.32 + // back to a PNG encoder. A return value of NS_OK implies successful data
1.33 + // extraction. If there are any unrecognized custom parse options in
1.34 + // aOptions, NS_ERROR_INVALID_ARG will be returned. When encountering this
1.35 + // error it is usual to call this function again without any options at all.
1.36 + static nsresult ExtractData(nsAString& aType,
1.37 + const nsAString& aOptions,
1.38 + const nsIntSize aSize,
1.39 + bool aUsePlaceholder,
1.40 + nsICanvasRenderingContextInternal* aContext,
1.41 + nsIInputStream** aStream);
1.42 +
1.43 + // Extracts data asynchronously. aType may change to "image/png" if we had to
1.44 + // fall back to a PNG encoder. aOptions are the options to be passed to the
1.45 + // encoder and aUsingCustomOptions specifies whether custom parse options were
1.46 + // used (i.e. by using -moz-parse-options). If there are any unrecognized
1.47 + // custom parse options, we fall back to the default values for the encoder
1.48 + // without any options at all. A return value of NS_OK only implies
1.49 + // successful dispatching of the extraction step to the encoding thread.
1.50 + static nsresult ExtractDataAsync(nsAString& aType,
1.51 + const nsAString& aOptions,
1.52 + bool aUsingCustomOptions,
1.53 + uint8_t* aImageBuffer,
1.54 + int32_t aFormat,
1.55 + const nsIntSize aSize,
1.56 + bool aUsePlaceholder,
1.57 + nsICanvasRenderingContextInternal* aContext,
1.58 + nsIScriptContext* aScriptContext,
1.59 + FileCallback& aCallback);
1.60 +
1.61 + // Gives you a stream containing the image represented by aImageBuffer.
1.62 + // The format is given in aFormat, for example
1.63 + // imgIEncoder::INPUT_FORMAT_HOSTARGB.
1.64 + static nsresult GetInputStream(int32_t aWidth,
1.65 + int32_t aHeight,
1.66 + uint8_t* aImageBuffer,
1.67 + int32_t aFormat,
1.68 + imgIEncoder* aEncoder,
1.69 + const char16_t* aEncoderOptions,
1.70 + nsIInputStream** aStream);
1.71 +
1.72 +private:
1.73 + // When called asynchronously, aContext is null.
1.74 + static nsresult
1.75 + ExtractDataInternal(const nsAString& aType,
1.76 + const nsAString& aOptions,
1.77 + uint8_t* aImageBuffer,
1.78 + int32_t aFormat,
1.79 + const nsIntSize aSize,
1.80 + bool aUsePlaceholder,
1.81 + nsICanvasRenderingContextInternal* aContext,
1.82 + nsIInputStream** aStream,
1.83 + imgIEncoder* aEncoder);
1.84 +
1.85 + // Creates and returns an encoder instance of the type specified in aType.
1.86 + // aType may change to "image/png" if no instance of the original type could
1.87 + // be created and we had to fall back to a PNG encoder. A null return value
1.88 + // should be interpreted as NS_IMAGELIB_ERROR_NO_ENCODER and aType is
1.89 + // undefined in this case.
1.90 + static already_AddRefed<imgIEncoder> GetImageEncoder(nsAString& aType);
1.91 +
1.92 + friend class EncodingRunnable;
1.93 +};
1.94 +
1.95 +} // namespace dom
1.96 +} // namespace mozilla
1.97 +
1.98 +#endif // ImageEncoder_h
