itkFEMLightObject.cxx

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/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkFEMLightObject.cxx,v $
  Language:  C++
  Date:      $Date: 2009-01-29 21:55:14 $
  Version:   $Revision: 1.19 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/

// disable debug warnings in MS compiler
#ifdef _MSC_VER
#pragma warning(disable: 4786)
#endif

#include "itkFEMLightObject.h"
#include "itkNumericTraits.h"

namespace itk {
namespace fem {

void FEMLightObject::Read( std::istream& f, void* )
{
  int n;

  this->SkipWhiteSpace(f); f>>n; if(!f) { goto out; }
  this->GN=n;

  out:

  if( !f )
    {
    throw FEMExceptionIO(__FILE__,__LINE__,"FEMLightObject::Read","Error reading FEM object!");
    }
}

void FEMLightObject::Write( std::ostream& f ) const
{
  // first write the class name
  f<<'<'<<FEMObjectFactory<Self>::ID2ClassName(this->ClassID())<<">\n";

  // then the global object number
  f<<"\t"<<GN<<"\t% Global object number\n";

  // check for errors
  if (!f)
    {
    throw FEMExceptionIO(__FILE__,__LINE__,"FEMLightObject::Write","Error writing FEM object!");
    }
}

FEMLightObject::Pointer
FEMLightObject::
CreateFromStream( std::istream& f, void *info )
{

// local variables
  std::streampos l(0);
  char buf[256];
  std::string s;
  std::string::size_type b,e;
  int clID;
  FEMLightObject::Pointer a=0;
  std::string errorMessage;

start:
#ifndef __sgi
  l=f.tellg();    // remember the stream position
#endif
  SkipWhiteSpace(f);      // skip comments and whitespaces
  if ( f.eof() ) return 0; // end of stream. all was good

  char c;
  if ( (c = f.get()) != '<' )
    {
    std::string rest;
    std::getline(f,rest);
    errorMessage = "Expected < token not found. Instead found '";
    errorMessage += c;
    errorMessage += "'.\nRest of line is '";
    errorMessage += rest;
    errorMessage += "'.\n";
    goto out; // we expect a token
    }
  f.getline(buf,256,'>');  // read up to 256 characters until '>' is reached. we read and discard the '>'
  s=std::string(buf);

  // get rid of the whitespaces in front of and the back of token
  b=s.find_first_not_of(whitespaces); // end of whitespaces in the beginning 
  if ( (e=s.find_first_of(whitespaces,b)) == std::string::npos )  // beginning of whitespaces at the end
    {
    e=s.size();
    }
  s=s.substr(b,e-b);

  if ( s=="END" )
    {
    /*
     * We can ignore this token. Start again by reading the next object.
     */
    goto start;
    }
  clID=FEMOF::ClassName2ID(s);  // obtain the class ID from FEMObjectFactory
  if (clID<0)
    {
    errorMessage = "Could not obtain class ID from FEMObjectFactory for '";
    errorMessage += s;
    errorMessage += "'.";
    goto out;  // class not found
    }
  // create a new object of the correct class
  a=FEMOF::Create(clID);
  if (!a)
    {
    errorMessage = "Error creating new object of the derived class";
    goto out;    // error creating new object of the derived class
    }
  /*
   * Now we have to read additional data, which is
   * specific to the class of object we just created
   */
  try
    {
    a->Read(f,info);
    }
  catch (...)
    {
#ifndef FEM_USE_SMART_POINTERS
    delete a;  // if something went wrong, we need to destroy the already created object
#endif
    a=0;
    throw;     // rethrow the same exception
    }

  if (a) { return a; }

  out:

#ifndef __sgi
  f.seekg(l);
#endif
  
  /*
   * Throw an IO exception
   */
  throw FEMExceptionIO(__FILE__,__LINE__,"FEMLightObject::ReadAnyObjectFromStream()",errorMessage);

}

// Helper function to skip all whitespaces and comments in input stream
void
FEMLightObject::
SkipWhiteSpace(std::istream& f)
{
  std::string skip;
  while(f && !f.eof() && (std::ws(f).peek()) == '%' )
    {
    std::getline(f,skip);
    }
}

// string containing all whitespace characters
const std::string
FEMLightObject
::whitespaces=" \t\n\r";

}} // end namespace itk::fem