png_decoder.h

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// Copyright 2016 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
#ifndef CORE_FXCODEC_PNG_PNG_DECODER_H_
#define CORE_FXCODEC_PNG_PNG_DECODER_H_
 
#include <memory>
 
#include "core/fxcodec/progressive_decoder_iface.h"
#include "core/fxcrt/retain_ptr.h"
 
#ifndef PDF_ENABLE_XFA_PNG
#error "PNG must be enabled"
#endif
 
namespace fxcodec {
 
class CFX_DIBAttribute;
 
class PngDecoder {
 public:
  class Delegate {
   public:
    virtual bool PngReadHeader(int width,
                               int height,
                               int bpc,
                               int pass,
                               int* color_type,
                               double* gamma) = 0;
 
    // Returns true on success. |pSrcBuf| will be set if this succeeds.
    // |pSrcBuf| does not take ownership of the buffer.
    virtual bool PngAskScanlineBuf(int line, uint8_t** pSrcBuf) = 0;
 
    virtual void PngFillScanlineBufCompleted(int pass, int line) = 0;
  };
 
  static std::unique_ptr<ProgressiveDecoderIface::Context> StartDecode(
      Delegate* pDelegate);
 
  static bool ContinueDecode(ProgressiveDecoderIface::Context* pContext,
                             RetainPtr<CFX_CodecMemory> codec_memory,
                             CFX_DIBAttribute* pAttribute);
 
  PngDecoder() = delete;
  PngDecoder(const PngDecoder&) = delete;
  PngDecoder& operator=(const PngDecoder&) = delete;
};
 
}  // namespace fxcodec
 
using PngDecoder = fxcodec::PngDecoder;
 
#endif  // CORE_FXCODEC_PNG_PNG_DECODER_H_