1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/image/decoders/nsIconDecoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,62 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + *
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef nsIconDecoder_h__
1.11 +#define nsIconDecoder_h__
1.12 +
1.13 +#include "Decoder.h"
1.14 +
1.15 +#include "nsCOMPtr.h"
1.16 +
1.17 +namespace mozilla {
1.18 +namespace image {
1.19 +class RasterImage;
1.20 +
1.21 +//////////////////////////////////////////////////////////////////////////////////////////////
1.22 +// The icon decoder is a decoder specifically tailored for loading icons
1.23 +// from the OS. We've defined our own little format to represent these icons
1.24 +// and this decoder takes that format and converts it into 24-bit RGB with alpha channel
1.25 +// support. It was modeled a bit off the PPM decoder.
1.26 +//
1.27 +// Assumptions about the decoder:
1.28 +// (1) We receive ALL of the data from the icon channel in one OnDataAvailable call. We don't
1.29 +// support multiple ODA calls yet.
1.30 +// (2) the format of the incoming data is as follows:
1.31 +// The first two bytes contain the width and the height of the icon.
1.32 +// The remaining bytes contain the icon data, 4 bytes per pixel, in
1.33 +// ARGB order (platform endianness, A in highest bits, B in lowest
1.34 +// bits), row-primary, top-to-bottom, left-to-right, with
1.35 +// premultiplied alpha.
1.36 +//
1.37 +//
1.38 +//////////////////////////////////////////////////////////////////////////////////////////////
1.39 +
1.40 +class nsIconDecoder : public Decoder
1.41 +{
1.42 +public:
1.43 +
1.44 + nsIconDecoder(RasterImage &aImage);
1.45 + virtual ~nsIconDecoder();
1.46 +
1.47 + virtual void WriteInternal(const char* aBuffer, uint32_t aCount, DecodeStrategy aStrategy);
1.48 +
1.49 + uint8_t mWidth;
1.50 + uint8_t mHeight;
1.51 + uint32_t mPixBytesRead;
1.52 + uint32_t mState;
1.53 +};
1.54 +
1.55 +enum {
1.56 + iconStateStart = 0,
1.57 + iconStateHaveHeight = 1,
1.58 + iconStateReadPixels = 2,
1.59 + iconStateFinished = 3
1.60 +};
1.61 +
1.62 +} // namespace image
1.63 +} // namespace mozilla
1.64 +
1.65 +#endif // nsIconDecoder_h__
