image/decoders/nsIconDecoder.h
author Mike Hommey <mh+mozilla@glandium.org>
Tue, 26 Mar 2019 16:29:17 +0000
changeset 466239 12b301ea0f924424f0a5057f1ebccc7cd8098e8e
parent 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1537641 - Make MIDL use clang-cl as a preprocessor. r=dmajor Using clang-cl as a preprocessor fails with: ``` In file included from z:\build\build\src\accessible\ipc\win\handler\HandlerData.idl:8: z:\build\build\src\accessible\ipc\win\handler/AccessibleHandler.h(27,8): error: pasting formed 'Accessible2_3.', an invalid preprocessing token [-Winvalid-token-paste] import NEWEST_IA2_IDL; ^ z:\build\build\src\accessible\ipc\win\handler/AccessibleHandler.h(15,24): note: expanded from macro 'NEWEST_IA2_IDL' ^ z:\build\build\src\accessible\ipc\win\handler/AccessibleHandler.h(14,22): note: expanded from macro 'IDLFOR' ^ z:\build\build\src\accessible\ipc\win\handler/AccessibleHandler.h(13,36): note: expanded from macro '__GENIDL' ^ 1 error generated. midl : command line error MIDL1003 : error returned by the C preprocessor (1) ``` There's only one place using the NEWEST_IA2_IDL and accompanying macros, we can just avoid the issue altogether by expanding it manually (and it's not like the macro buys much, the other arm of the __midl ifdef has a #include "Accessible2_3.h" that doesn't use the macro either, presumably for the same reason). Differential Revision: https://phabricator.services.mozilla.com/D24868

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 mozilla_image_decoders_nsIconDecoder_h
#define mozilla_image_decoders_nsIconDecoder_h

#include "Decoder.h"
#include "StreamingLexer.h"
#include "SurfacePipe.h"

namespace mozilla {
namespace image {

class RasterImage;

////////////////////////////////////////////////////////////////////////////////
// The icon decoder is a decoder specifically tailored for loading icons
// from the OS. We've defined our own little format to represent these icons
// and this decoder takes that format and converts it into 24-bit RGB with
// alpha channel support. It was modeled a bit off the PPM decoder.
//
// The format of the incoming data is as follows:
//
// The first two bytes contain the width and the height of the icon.
// The remaining bytes contain the icon data, 4 bytes per pixel, in
// ARGB order (platform endianness, A in highest bits, B in lowest
// bits), row-primary, top-to-bottom, left-to-right, with
// premultiplied alpha.
//
////////////////////////////////////////////////////////////////////////////////

class nsIconDecoder : public Decoder {
 public:
  virtual ~nsIconDecoder();

  DecoderType GetType() const override { return DecoderType::ICON; }

  LexerResult DoDecode(SourceBufferIterator& aIterator,
                       IResumable* aOnResume) override;

 private:
  friend class DecoderFactory;

  // Decoders should only be instantiated via DecoderFactory.
  explicit nsIconDecoder(RasterImage* aImage);

  enum class State { HEADER, ROW_OF_PIXELS, FINISH };

  LexerTransition<State> ReadHeader(const char* aData);
  LexerTransition<State> ReadRowOfPixels(const char* aData, size_t aLength);
  LexerTransition<State> Finish();

  StreamingLexer<State> mLexer;
  SurfacePipe mPipe;
  uint32_t mBytesPerRow;
};

}  // namespace image
}  // namespace mozilla

#endif  // mozilla_image_decoders_nsIconDecoder_h