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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.imaging.formats.png.chunks;
18  
19  import java.io.ByteArrayInputStream;
20  
21  import org.apache.commons.imaging.common.BinaryFileParser;
22  
23  public class PngChunk extends BinaryFileParser {
24      public final int length;
25      public final int chunkType;
26      public final int crc;
27      private final byte[] bytes;
28  
29      private final boolean[] propertyBits;
30      public final boolean ancillary;
31      public final boolean isPrivate;
32      public final boolean reserved;
33      public final boolean safeToCopy;
34  
35      public PngChunk(final int length, final int chunkType, final int crc, final byte[] bytes) {
36          this.length = length;
37          this.chunkType = chunkType;
38          this.crc = crc;
39          this.bytes = bytes; // TODO clone?
40  
41          propertyBits = new boolean[4];
42          int shift = 24;
43          for (int i = 0; i < 4; i++) {
44              final int theByte = 0xff & (chunkType >> shift);
45              shift -= 8;
46              final int theMask = 1 << 5;
47              propertyBits[i] = ((theByte & theMask) > 0);
48          }
49  
50          ancillary = propertyBits[0];
51          isPrivate = propertyBits[1];
52          reserved = propertyBits[2];
53          safeToCopy = propertyBits[3];
54      }
55  
56      public byte[] getBytes() {
57          return bytes; // TODO clone?
58      }
59  
60      public boolean[] getPropertyBits() {
61          return propertyBits.clone();
62      }
63  
64      protected ByteArrayInputStream getDataStream() {
65          return new ByteArrayInputStream(getBytes());
66      }
67  
68  }