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-rw-r--r--dom/base/ImageEncoder.h138
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diff --git a/dom/base/ImageEncoder.h b/dom/base/ImageEncoder.h
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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 "nsLayoutUtils.h"
+#include "nsSize.h"
+
+class nsICanvasRenderingContextInternal;
+class nsIThreadPool;
+
+namespace mozilla {
+
+namespace layers {
+class AsyncCanvasRenderer;
+class Image;
+} // namespace layers
+
+namespace dom {
+
+class EncodeCompleteCallback;
+class EncodingRunnable;
+
+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,
+ nsICanvasRenderingContextInternal* aContext,
+ layers::AsyncCanvasRenderer* aRenderer,
+ 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,
+ 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,
+ 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 char16_t* 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,
+ layers::Image* aImage,
+ nsICanvasRenderingContextInternal* aContext,
+ layers::AsyncCanvasRenderer* aRenderer,
+ 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);
+
+ static nsresult EnsureThreadPool();
+
+ // Thread pool for dispatching EncodingRunnable.
+ static StaticRefPtr<nsIThreadPool> sThreadPool;
+
+ friend class EncodingRunnable;
+ friend class EncoderThreadPoolTerminator;
+};
+
+/**
+ * The callback interface of ExtractDataAsync and ExtractDataFromLayersImageAsync.
+ * ReceiveBlob() is called on main thread when encoding is complete.
+ */
+class EncodeCompleteCallback
+{
+public:
+ NS_INLINE_DECL_THREADSAFE_REFCOUNTING(EncodeCompleteCallback)
+
+ virtual nsresult ReceiveBlob(already_AddRefed<Blob> aBlob) = 0;
+
+protected:
+ virtual ~EncodeCompleteCallback() {}
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // ImageEncoder_h