nsICODecoder.h - mozsearch

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/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=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_nsICODecoder_h

#define mozilla_image_decoders_nsICODecoder_h

#include "StreamingLexer.h"

#include "Decoder.h"

#include "Downscaler.h"

#include "imgFrame.h"

#include "mozilla/gfx/2D.h"

#include "nsBMPDecoder.h"

#include "nsPNGDecoder.h"

#include "ICOFileHeaders.h"

namespace mozilla {

namespace image {

class RasterImage;

enum class ICOState {

  HEADER,

  DIR_ENTRY,

  FINISHED_DIR_ENTRY,

  ITERATE_UNSIZED_DIR_ENTRY,

  SKIP_TO_RESOURCE,

  FOUND_RESOURCE,

  SNIFF_RESOURCE,

  READ_RESOURCE,

  PREPARE_FOR_MASK,

  READ_MASK_ROW,

  FINISH_MASK,

  SKIP_MASK,

  FINISHED_RESOURCE

};

class nsICODecoder : public Decoder {

 public:

  virtual ~nsICODecoder() {}

  /// @return The offset from the beginning of the ICO to the first resource.

  size_t FirstResourceOffset() const;

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

  LexerResult DoDecode(SourceBufferIterator& aIterator,

                       IResumable* aOnResume) override;

  nsresult FinishInternal() override;

  nsresult FinishWithErrorInternal() override;

 private:

  friend class DecoderFactory;

  // Decoders should only be instantiated via DecoderFactory.

  explicit nsICODecoder(RasterImage* aImage);

  // Flushes the contained decoder to read all available data and sets the

  // appropriate errors. Returns true if there are no errors.

  bool FlushContainedDecoder();

  // Gets decoder state from the contained decoder so it's visible externally.

  nsresult GetFinalStateFromContainedDecoder();

  // Obtains the number of colors from the BPP, mBPP must be filled in

  uint16_t GetNumColors();

  LexerTransition<ICOState> ReadHeader(const char* aData);

  LexerTransition<ICOState> ReadDirEntry(const char* aData);

  LexerTransition<ICOState> IterateUnsizedDirEntry();

  LexerTransition<ICOState> FinishDirEntry();

  LexerTransition<ICOState> SniffResource(const char* aData);

  LexerTransition<ICOState> ReadResource();

  LexerTransition<ICOState> ReadBIH(const char* aData);

  LexerTransition<ICOState> PrepareForMask();

  LexerTransition<ICOState> ReadMaskRow(const char* aData);

  LexerTransition<ICOState> FinishMask();

  LexerTransition<ICOState> FinishResource();

  struct IconDirEntryEx : public IconDirEntry {

    OrientedIntSize mSize;

};

  StreamingLexer<ICOState, 32> mLexer;  // The lexer.

  Maybe<Downscaler> mDownscaler;        // The downscaler used for the mask.

  RefPtr<Decoder> mContainedDecoder;    // Either a BMP or PNG decoder.

  Maybe<SourceBufferIterator>

      mReturnIterator;               // Iterator to save return point.

  UniquePtr<uint8_t[]> mMaskBuffer;  // A temporary buffer for the alpha mask.

  nsTArray<IconDirEntryEx> mDirEntries;  // Valid dir entries with a size.

  nsTArray<IconDirEntryEx> mUnsizedDirEntries;  // Dir entries without a size.

  IconDirEntryEx* mDirEntry;  // The dir entry for the selected resource.

  uint16_t mNumIcons;         // Stores the number of icons in the ICO file.

  uint16_t mCurrIcon;  // Stores the current dir entry index we are processing.

  uint16_t mBPP;       // The BPP of the resource we're decoding.

  uint32_t

      mMaskRowSize;  // The size in bytes of each row in the BMP alpha mask.

  uint32_t mCurrMaskLine;  // The line of the BMP alpha mask we're processing.

  bool mIsCursor;          // Is this ICO a cursor?

  bool mHasMaskAlpha;      // Did the BMP alpha mask have any transparency?

};

}  // namespace image

}  // namespace mozilla

#endif  // mozilla_image_decoders_nsICODecoder_h