gecko-dev/image/decoders/nsICODecoder.h

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/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=4: */
/* 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 "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,
SKIP_TO_RESOURCE,
FOUND_RESOURCE,
SNIFF_RESOURCE,
READ_PNG,
READ_BIH,
READ_BMP,
PREPARE_FOR_MASK,
READ_MASK_ROW,
FINISH_MASK,
SKIP_MASK,
FINISHED_RESOURCE
};
class nsICODecoder : public Decoder
{
public:
virtual ~nsICODecoder() { }
/// @return the width of the icon directory entry @aEntry.
static uint32_t GetRealWidth(const IconDirEntry& aEntry)
{
return aEntry.mWidth == 0 ? 256 : aEntry.mWidth;
}
/// @return the width of the selected directory entry (mDirEntry).
uint32_t GetRealWidth() const { return GetRealWidth(mDirEntry); }
/// @return the height of the icon directory entry @aEntry.
static uint32_t GetRealHeight(const IconDirEntry& aEntry)
{
return aEntry.mHeight == 0 ? 256 : aEntry.mHeight;
}
/// @return the height of the selected directory entry (mDirEntry).
uint32_t GetRealHeight() const { return GetRealHeight(mDirEntry); }
/// @return the size of the selected directory entry (mDirEntry).
gfx::IntSize GetRealSize() const
{
return gfx::IntSize(GetRealWidth(), GetRealHeight());
}
/// @return The offset from the beginning of the ICO to the first resource.
size_t FirstResourceOffset() const;
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);
// Writes to the contained decoder and sets the appropriate errors
// Returns true if there are no errors.
bool WriteToContainedDecoder(const char* aBuffer, uint32_t aCount);
// Gets decoder state from the contained decoder so it's visible externally.
nsresult GetFinalStateFromContainedDecoder();
/**
* Verifies that the width and height values in @aBIH are valid and match the
* values we read from the ICO directory entry. If everything looks OK, the
* height value in @aBIH is updated to compensate for the AND mask, which the
* underlying BMP decoder doesn't know about.
*
* @return true if the width and height values in @aBIH are valid and correct.
*/
bool CheckAndFixBitmapSize(int8_t* aBIH);
// 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> SniffResource(const char* aData);
LexerTransition<ICOState> ReadPNG(const char* aData, uint32_t aLen);
LexerTransition<ICOState> ReadBIH(const char* aData);
LexerTransition<ICOState> ReadBMP(const char* aData, uint32_t aLen);
LexerTransition<ICOState> PrepareForMask();
LexerTransition<ICOState> ReadMaskRow(const char* aData);
LexerTransition<ICOState> FinishMask();
LexerTransition<ICOState> FinishResource();
StreamingLexer<ICOState, 32> mLexer; // The lexer.
RefPtr<Decoder> mContainedDecoder; // Either a BMP or PNG decoder.
RefPtr<SourceBuffer> mContainedSourceBuffer; // SourceBuffer for mContainedDecoder.
UniquePtr<uint8_t[]> mMaskBuffer; // A temporary buffer for the alpha mask.
char mBIHraw[bmp::InfoHeaderLength::WIN_ICO]; // The bitmap information header.
IconDirEntry mDirEntry; // The dir entry for the selected resource.
gfx::IntSize mBiggestResourceSize; // Used to select the intrinsic size.
gfx::IntSize mBiggestResourceHotSpot; // Used to select the intrinsic size.
uint16_t mBiggestResourceColorDepth; // Used to select the intrinsic size.
int32_t mBestResourceDelta; // Used to select the best resource.
uint16_t mBestResourceColorDepth; // Used to select the best 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