001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.imaging.formats.png.transparencyfilters; 018 019import java.io.IOException; 020 021import org.apache.commons.imaging.ImagingException; 022import org.apache.commons.imaging.common.BinaryFileParser; 023 024public abstract class AbstractTransparencyFilter extends BinaryFileParser { 025 026 private final byte[] bytes; 027 028 /** 029 * Constructs a new instance. 030 * 031 * @param bytes bytes. 032 */ 033 public AbstractTransparencyFilter(final byte[] bytes) { 034 this.bytes = bytes.clone(); 035 } 036 037 public abstract int filter(int rgb, int index) throws ImagingException, IOException; 038 039 /** 040 * Gets the byte at the given offset. 041 * 042 * @param offset offset. 043 * @return a byte. 044 */ 045 public byte getByte(final int offset) { 046 return bytes[offset]; 047 } 048 049 /** 050 * Gets the length. 051 * 052 * @return the length 053 */ 054 public int getLength() { 055 return bytes.length; 056 } 057}