gecko-dev/image/decoders/nsPNGDecoder.h

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3.4 KiB
C++

/* -*- 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 nsPNGDecoder_h__
#define nsPNGDecoder_h__
#include "Decoder.h"
#include "imgDecoderObserver.h"
#include "gfxASurface.h"
#include "nsCOMPtr.h"
#include "png.h"
#include "qcms.h"
namespace mozilla {
namespace image {
class RasterImage;
class nsPNGDecoder : public Decoder
{
public:
nsPNGDecoder(RasterImage &aImage, imgDecoderObserver* aObserver);
virtual ~nsPNGDecoder();
virtual void InitInternal();
virtual void WriteInternal(const char* aBuffer, uint32_t aCount);
virtual Telemetry::ID SpeedHistogram();
void CreateFrame(png_uint_32 x_offset, png_uint_32 y_offset,
int32_t width, int32_t height,
gfxASurface::gfxImageFormat format);
void SetAnimFrameInfo();
void EndImageFrame();
// Check if PNG is valid ICO (32bpp RGBA)
// http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
bool IsValidICO() const
{
// If there are errors in the call to png_get_IHDR, the error_callback in
// nsPNGDecoder.cpp is called. In this error callback we do a longjmp, so
// we need to save the jump buffer here. Oterwise we'll end up without a
// proper callstack.
if (setjmp(png_jmpbuf(mPNG))) {
// We got here from a longjmp call indirectly from png_get_IHDR
return false;
}
png_uint_32
png_width, // Unused
png_height; // Unused
int png_bit_depth,
png_color_type;
if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
&png_color_type, NULL, NULL, NULL)) {
return (png_color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
png_bit_depth == 8);
} else {
return false;
}
}
public:
png_structp mPNG;
png_infop mInfo;
nsIntRect mFrameRect;
uint8_t *mCMSLine;
uint8_t *interlacebuf;
uint8_t *mImageData;
qcms_profile *mInProfile;
qcms_transform *mTransform;
gfxASurface::gfxImageFormat format;
// For size decodes
uint8_t *mHeaderBuf;
uint32_t mHeaderBytesRead;
uint8_t mChannels;
bool mFrameHasNoAlpha;
bool mFrameIsHidden;
// whether CMS or premultiplied alpha are forced off
uint32_t mCMSMode;
bool mDisablePremultipliedAlpha;
/*
* libpng callbacks
*
* We put these in the class so that they can access protected members.
*/
static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr);
static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row,
png_uint_32 row_num, int pass);
#ifdef PNG_APNG_SUPPORTED
static void PNGAPI frame_info_callback(png_structp png_ptr,
png_uint_32 frame_num);
#endif
static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr);
static void PNGAPI error_callback(png_structp png_ptr,
png_const_charp error_msg);
static void PNGAPI warning_callback(png_structp png_ptr,
png_const_charp warning_msg);
// This is defined in the PNG spec as an invariant. We use it to
// do manual validation without libpng.
static const uint8_t pngSignatureBytes[];
};
} // namespace image
} // namespace mozilla
#endif // nsPNGDecoder_h__