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// =================================================================================================
// ADOBE SYSTEMS INCORPORATED
// Copyright 2006 Adobe Systems Incorporated
// All Rights Reserved
//
// NOTICE: Adobe permits you to use, modify, and distribute this file in accordance with the terms
// of the Adobe license agreement accompanying it.
// =================================================================================================
#include "public/include/XMP_Environment.h" // ! XMP_Environment.h must be the first included header.
#include "public/include/XMP_Const.h"
#include "XMPFiles/source/FileHandlers/PNG_Handler.hpp"
#include "XMPFiles/source/FormatSupport/PNG_Support.hpp"
#include "source/XIO.hpp"
using namespace std;
// =================================================================================================
/// \file PNG_Handler.hpp
/// \brief File format handler for PNG.
///
/// This handler ...
///
// =================================================================================================
// =================================================================================================
// PNG_MetaHandlerCTor
// ====================
XMPFileHandler * PNG_MetaHandlerCTor ( XMPFiles * parent )
{
return new PNG_MetaHandler ( parent );
} // PNG_MetaHandlerCTor
// =================================================================================================
// PNG_CheckFormat
// ===============
bool PNG_CheckFormat ( XMP_FileFormat format,
XMP_StringPtr filePath,
XMP_IO* fileRef,
XMPFiles * parent )
{
IgnoreParam(format); IgnoreParam(fileRef); IgnoreParam(parent);
XMP_Assert ( format == kXMP_PNGFile );
if ( fileRef->Length() < PNG_SIGNATURE_LEN ) return false;
XMP_Uns8 buffer [PNG_SIGNATURE_LEN];
fileRef->Rewind();
fileRef->Read ( buffer, PNG_SIGNATURE_LEN );
if ( ! CheckBytes ( buffer, PNG_SIGNATURE_DATA, PNG_SIGNATURE_LEN ) ) return false;
return true;
} // PNG_CheckFormat
// =================================================================================================
// PNG_MetaHandler::PNG_MetaHandler
// ==================================
PNG_MetaHandler::PNG_MetaHandler ( XMPFiles * _parent )
{
this->parent = _parent;
this->handlerFlags = kPNG_HandlerFlags;
this->stdCharForm = kXMP_Char8Bit;
}
// =================================================================================================
// PNG_MetaHandler::~PNG_MetaHandler
// ===================================
PNG_MetaHandler::~PNG_MetaHandler()
{
}
// =================================================================================================
// PNG_MetaHandler::CacheFileData
// ===============================
void PNG_MetaHandler::CacheFileData()
{
this->containsXMP = false;
XMP_IO* fileRef ( this->parent->ioRef );
if ( fileRef == 0) return;
PNG_Support::ChunkState chunkState;
long numChunks = PNG_Support::OpenPNG ( fileRef, chunkState );
if ( numChunks == 0 ) return;
if (chunkState.xmpLen != 0)
{
// XMP present
this->xmpPacket.reserve(chunkState.xmpLen);
this->xmpPacket.assign(chunkState.xmpLen, ' ');
if (PNG_Support::ReadBuffer ( fileRef, chunkState.xmpPos, chunkState.xmpLen, const_cast<char *>(this->xmpPacket.data()) ))
{
this->packetInfo.offset = chunkState.xmpPos;
this->packetInfo.length = chunkState.xmpLen;
this->containsXMP = true;
}
}
else
{
// no XMP
}
} // PNG_MetaHandler::CacheFileData
// =================================================================================================
// PNG_MetaHandler::ProcessXMP
// ============================
//
// Process the raw XMP and legacy metadata that was previously cached.
void PNG_MetaHandler::ProcessXMP()
{
this->processedXMP = true; // Make sure we only come through here once.
// Process the XMP packet.
if ( ! this->xmpPacket.empty() ) {
XMP_Assert ( this->containsXMP );
XMP_StringPtr packetStr = this->xmpPacket.c_str();
XMP_StringLen packetLen = (XMP_StringLen)this->xmpPacket.size();
this->xmpObj.ParseFromBuffer ( packetStr, packetLen );
this->containsXMP = true;
}
} // PNG_MetaHandler::ProcessXMP
// =================================================================================================
// PNG_MetaHandler::UpdateFile
// ============================
void PNG_MetaHandler::UpdateFile ( bool doSafeUpdate )
{
bool updated = false;
if ( ! this->needsUpdate ) return;
if ( doSafeUpdate ) XMP_Throw ( "PNG_MetaHandler::UpdateFile: Safe update not supported", kXMPErr_Unavailable );
XMP_StringPtr packetStr = xmpPacket.c_str();
XMP_StringLen packetLen = (XMP_StringLen)xmpPacket.size();
if ( packetLen == 0 ) return;
XMP_IO* fileRef(this->parent->ioRef);
if ( fileRef == 0 ) return;
PNG_Support::ChunkState chunkState;
long numChunks = PNG_Support::OpenPNG ( fileRef, chunkState );
if ( numChunks == 0 ) return;
// write/update chunk
if (chunkState.xmpLen == 0)
{
// no current chunk -> inject
updated = SafeWriteFile();
}
else if (chunkState.xmpLen >= packetLen )
{
// current chunk size is sufficient -> write and update CRC (in place update)
updated = PNG_Support::WriteBuffer(fileRef, chunkState.xmpPos, packetLen, packetStr );
PNG_Support::UpdateChunkCRC(fileRef, chunkState.xmpChunk );
}
else if (chunkState.xmpLen < packetLen)
{
// XMP is too large for current chunk -> expand
updated = SafeWriteFile();
}
if ( ! updated )return; // If there's an error writing the chunk, bail.
this->needsUpdate = false;
} // PNG_MetaHandler::UpdateFile
// =================================================================================================
// PNG_MetaHandler::WriteTempFile
// ==============================
void PNG_MetaHandler::WriteTempFile ( XMP_IO* tempRef )
{
XMP_IO* originalRef = this->parent->ioRef;
PNG_Support::ChunkState chunkState;
long numChunks = PNG_Support::OpenPNG ( originalRef, chunkState );
if ( numChunks == 0 ) return;
tempRef->Truncate ( 0 );
tempRef->Write ( PNG_SIGNATURE_DATA, PNG_SIGNATURE_LEN );
PNG_Support::ChunkIterator curPos = chunkState.chunks.begin();
PNG_Support::ChunkIterator endPos = chunkState.chunks.end();
for (; (curPos != endPos); ++curPos)
{
PNG_Support::ChunkData chunk = *curPos;
// discard existing XMP chunk
if (chunk.xmp)
continue;
// copy any other chunk
PNG_Support::CopyChunk(originalRef, tempRef, chunk);
// place XMP chunk immediately after IHDR-chunk
if (PNG_Support::CheckIHDRChunkHeader(chunk))
{
XMP_StringPtr packetStr = xmpPacket.c_str();
XMP_StringLen packetLen = (XMP_StringLen)xmpPacket.size();
PNG_Support::WriteXMPChunk(tempRef, packetLen, packetStr );
}
}
} // PNG_MetaHandler::WriteTempFile
// =================================================================================================
// PNG_MetaHandler::SafeWriteFile
// ==============================
bool PNG_MetaHandler::SafeWriteFile()
{
XMP_IO* originalFile = this->parent->ioRef;
XMP_IO* tempFile = originalFile->DeriveTemp();
if ( tempFile == 0 ) XMP_Throw ( "Failure creating PNG temp file", kXMPErr_InternalFailure );
this->WriteTempFile ( tempFile );
originalFile->AbsorbTemp();
return true;
} // PNG_MetaHandler::SafeWriteFile
// =================================================================================================
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