зеркало из https://github.com/mozilla/gecko-dev.git
67 строки
2.0 KiB
C++
67 строки
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef nsIconDecoder_h__
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#define nsIconDecoder_h__
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#include "Decoder.h"
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#include "nsCOMPtr.h"
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#include "imgIDecoderObserver.h"
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namespace mozilla {
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namespace image {
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class RasterImage;
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//////////////////////////////////////////////////////////////////////////////////////////////
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// The icon decoder is a decoder specifically tailored for loading icons
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// from the OS. We've defined our own little format to represent these icons
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// and this decoder takes that format and converts it into 24-bit RGB with alpha channel
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// support. It was modeled a bit off the PPM decoder.
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//
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// Assumptions about the decoder:
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// (1) We receive ALL of the data from the icon channel in one OnDataAvailable call. We don't
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// support multiple ODA calls yet.
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// (2) the format of the incoming data is as follows:
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// The first two bytes contain the width and the height of the icon.
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// The remaining bytes contain the icon data, 4 bytes per pixel, in
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// ARGB order (platform endianness, A in highest bits, B in lowest
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// bits), row-primary, top-to-bottom, left-to-right, with
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// premultiplied alpha.
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//
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//
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//////////////////////////////////////////////////////////////////////////////////////////////
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class nsIconDecoder : public Decoder
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{
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public:
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nsIconDecoder(RasterImage &aImage, imgIDecoderObserver* aObserver);
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virtual ~nsIconDecoder();
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virtual void WriteInternal(const char* aBuffer, uint32_t aCount);
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uint8_t mWidth;
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uint8_t mHeight;
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uint32_t mPixBytesRead;
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uint32_t mPixBytesTotal;
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uint8_t* mImageData;
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uint32_t mState;
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};
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enum {
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iconStateStart = 0,
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iconStateHaveHeight = 1,
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iconStateReadPixels = 2,
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iconStateFinished = 3
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};
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} // namespace image
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} // namespace mozilla
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#endif // nsIconDecoder_h__
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