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/*
 * XSEC
 *
 * TXFMChain := List class that holds and manipulates a chain of TXFM 
 *              objects.
 *
 * Author(s): Berin Lautenbach
 *
 * $Id: TXFMChain.cpp,v 1.1 2003/02/21 11:53:08 blautenb Exp $
 *
 */

#include <xsec/transformers/TXFMBase.hpp>
#include <xsec/transformers/TXFMChain.hpp>


// -----------------------------------------------------------------------
//  deleteTransformChain = easy way to delete an entire chain of transforms
// -----------------------------------------------------------------------


void TXFMChain::deleteTXFMChain(TXFMBase * toDelete) {

	if (toDelete != NULL) {
		deleteTXFMChain(toDelete->input);
		delete toDelete;
	}

}

// --------------------------------------------------------------------------------
//           Constructors/Destructors
// --------------------------------------------------------------------------------

TXFMChain::TXFMChain(TXFMBase * baseTxfm, bool deleteChainWhenDone) :
mp_currentTxfm(baseTxfm),
m_deleteChainWhenDone(deleteChainWhenDone) {
}

TXFMChain::~TXFMChain() {

	if (m_deleteChainWhenDone)
		deleteTXFMChain(mp_currentTxfm);

}

// --------------------------------------------------------------------------------
//           Read hash
// --------------------------------------------------------------------------------

void TXFMChain::appendTxfm(TXFMBase * txfm) {

	TXFMBase * oldTxfm = mp_currentTxfm;
	mp_currentTxfm = txfm;

	// This may throw an exception, but if it does each TXFM type 
	// Guarantees that it will have made the input part of the 
	// chain before such an exception.  So the caller can clear out
	// the entire chain - including the new txfm - by deleting
	// *this.

	txfm->setInput(oldTxfm);

}