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/* ====================================================================
   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.
==================================================================== */

package org.apache.poi.hdgf.streams;

import org.apache.poi.hdgf.chunks.ChunkFactory;
import org.apache.poi.hdgf.pointers.Pointer;
import org.apache.poi.hdgf.pointers.PointerFactory;
import org.apache.poi.util.LittleEndian;

/**
 * A stream that holds pointers, possibly in addition to some
 *  other data too.
 */
public class PointerContainingStream extends Stream { // TODO - instantiable superclass
	private Pointer[] childPointers;
	private Stream[] childStreams;

	private ChunkFactory chunkFactory;
	private PointerFactory pointerFactory;
	private int numPointersLocalOffset;

	protected PointerContainingStream(Pointer pointer, StreamStore store, ChunkFactory chunkFactory, PointerFactory pointerFactory) {
		super(pointer, store);
		this.chunkFactory = chunkFactory;
		this.pointerFactory = pointerFactory;

		// Find the offset to the number of child pointers we have
		// This ought to be the first thing stored in us
		numPointersLocalOffset = (int)LittleEndian.getUInt(
				store.getContents(), 0
		);

		// Generate the objects for the pointers we contain
		int numPointers = (int)LittleEndian.getUInt(
				store.getContents(), numPointersLocalOffset
		);
		childPointers = new Pointer[numPointers];

		// After the number of pointers is another (unknown)
		//  4 byte value
		int pos = numPointersLocalOffset + 4 + 4;

		// Now create the pointer objects
		for(int i=0; i