/*
 * 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.sanselan.formats.png.chunks;

import java.io.ByteArrayInputStream;

import org.apache.sanselan.common.BinaryFileParser;

public class PNGChunk extends BinaryFileParser
{
	public final int length;
	public final int chunkType;
	public final int crc;
	public final byte bytes[];

	public final boolean propertyBits[];
	public final boolean ancillary, isPrivate, reserved, safeToCopy;

	public PNGChunk(int Length, int ChunkType, int CRC, byte bytes[])
	{
		this.length = Length;
		this.chunkType = ChunkType;
		this.crc = CRC;
		this.bytes = bytes;

		propertyBits = new boolean[4];
		int shift = 24;
		for (int i = 0; i < 4; i++)
		{
			int theByte = 0xff & (ChunkType >> shift);
			shift -= 8;
			int theMask = 1 << 5;
			propertyBits[i] = ((theByte & theMask) > 0);
		}

		ancillary = propertyBits[0];
		isPrivate = propertyBits[1];
		reserved = propertyBits[2];
		safeToCopy = propertyBits[3];
	}

	protected ByteArrayInputStream getDataStream()
	{
		ByteArrayInputStream is = new ByteArrayInputStream(bytes);
		return is;
	}

}