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 18 19package org.apache.harmony.x.imageio.plugins.png; 20 21import org.apache.harmony.x.imageio.plugins.jpeg.JPEGSpiConsts; 22 23import javax.imageio.spi.ImageReaderSpi; 24import javax.imageio.spi.ServiceRegistry; 25import javax.imageio.ImageReader; 26import javax.imageio.stream.ImageInputStream; 27import java.io.IOException; 28import java.util.Locale; 29 30public class PNGImageReaderSpi extends ImageReaderSpi { 31 static final String PNG_NAMES[] = new String[] {"png", "PNG"}; 32 static final String PNG_SUFFIXES[] = new String[] {"png"}; 33 static final String PNG_MIME_TYPES[] = new String[] {"image/png"}; 34 static final String PNG_READER_CLASS_NAME = "org.apache.harmony.x.imageio.plugins.png.PNGImageReader"; 35 static final String PNG_READER_SPI_NAMES[] = {"org.apache.harmony.x.imageio.plugins.png.PNGImageReaderSpi"}; 36 37 public PNGImageReaderSpi() { 38 super( 39 JPEGSpiConsts.vendorName, JPEGSpiConsts.version, 40 PNG_NAMES, PNG_SUFFIXES, 41 PNG_MIME_TYPES, PNG_READER_CLASS_NAME, 42 STANDARD_INPUT_TYPE, null, 43 false, null, 44 null, null, 45 null, false, 46 null, null, 47 null, null 48 ); 49 } 50 51 @Override 52 public boolean canDecodeInput(Object source) throws IOException { 53 ImageInputStream markable = (ImageInputStream) source; 54 markable.mark(); 55 56 byte[] signature = new byte[8]; 57 markable.seek(0); 58 59 int nBytes = markable.read(signature, 0, 8); 60 if(nBytes != 8) markable.read(signature, nBytes, 8-nBytes); 61 markable.reset(); 62 63 // PNG signature: 137 80 78 71 13 10 26 10 64 return (signature[0] & 0xFF) == 137 && 65 (signature[1] & 0xFF) == 80 && 66 (signature[2] & 0xFF) == 78 && 67 (signature[3] & 0xFF) == 71 && 68 (signature[4] & 0xFF) == 13 && 69 (signature[5] & 0xFF) == 10 && 70 (signature[6] & 0xFF) == 26 && 71 (signature[7] & 0xFF) == 10; 72 } 73 74 @Override 75 public ImageReader createReaderInstance(Object extension) throws IOException { 76 return new PNGImageReader(this); 77 } 78 79 @Override 80 public String getDescription(Locale locale) { 81 return "DRL PNG decoder"; 82 } 83 84 @Override 85 public void onRegistration(ServiceRegistry registry, Class<?> category) { 86 super.onRegistration(registry, category); 87 } 88} 89