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.transparencyfilters;
18
19 import java.io.IOException;
20
21 import org.apache.commons.imaging.ImagingException;
22 import org.apache.commons.imaging.common.BinaryFileParser;
23
24 public abstract class AbstractTransparencyFilter extends BinaryFileParser {
25
26 private final byte[] bytes;
27
28 /**
29 * Constructs a new instance.
30 *
31 * @param bytes bytes.
32 */
33 public AbstractTransparencyFilter(final byte[] bytes) {
34 this.bytes = bytes.clone();
35 }
36
37 public abstract int filter(int rgb, int index) throws ImagingException, IOException;
38
39 /**
40 * Gets the byte at the given offset.
41 *
42 * @param offset offset.
43 * @return a byte.
44 */
45 public byte getByte(final int offset) {
46 return bytes[offset];
47 }
48
49 /**
50 * Gets the length.
51 *
52 * @return the length
53 */
54 public int getLength() {
55 return bytes.length;
56 }
57 }