/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



#ifndef _UNOTOOLS_STREAMSECTION_HXX_
#define _UNOTOOLS_STREAMSECTION_HXX_

#include <com/sun/star/io/XMarkableStream.hpp>
#include <com/sun/star/io/XDataInputStream.hpp>
#include <com/sun/star/io/XDataOutputStream.hpp>

namespace utl
{

	namespace stario	= ::com::sun::star::io;
	namespace staruno	= ::com::sun::star::uno;

/** implements handling for compatibly reading/writing data from/into an input/output stream.
	data written in a block secured by this class should be readable by older versions which
	use the same mechanism.

	@author	Frank Schoenheit
	@since	00/26/05
*/

class OStreamSection
{
	staruno::Reference< stario::XMarkableStream >		m_xMarkStream;
	staruno::Reference< stario::XDataInputStream >		m_xInStream;
	staruno::Reference< stario::XDataOutputStream >		m_xOutStream;

	sal_Int32	m_nBlockStart;
	sal_Int32	m_nBlockLen;

public:
	/**	starts reading of a "skippable" section of data within the given input stream<BR>
		@param		_rxInput	the stream to read from. Must support the
								<type scope="com::sun::star::io">XMarkableStream</type> interface
	*/
	OStreamSection(const staruno::Reference< stario::XDataInputStream >& _rxInput);

	/**	starts writing of a "skippable" section of data into the given output stream
		@param		_rxOutput			the stream the stream to write to. Must support the
										<type scope="com::sun::star::io">XMarkableStream</type> interface
		@param		_nPresumedLength	estimation for the length of the upcoming section. If greater 0, this
										value will be written as section length and corrected (in the dtor) only if
										needed. If you know how much bytes you are about to write, you may
										want to use this param, saving some stream operations this way.
	*/
	OStreamSection(const staruno::Reference< stario::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength = 0);

	/** dtor. <BR>If constructed for writing, the section "opened" by this object will be "closed".<BR>
		If constructed for reading, any remaining bytes 'til the end of the section will be skipped.
	*/
	~OStreamSection();
};

}	// namespace utl

#endif // _UNOTOOLS_STREAMSECTION_HXX_