    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.chunks;
    018
    019import static org.apache.commons.imaging.common.BinaryFunctions.read4Bytes;
    020import static org.apache.commons.imaging.common.BinaryFunctions.readByte;
    021
    022import java.io.ByteArrayInputStream;
    023import java.io.IOException;
    024
    025import org.apache.commons.imaging.ImagingException;
    026import org.apache.commons.imaging.formats.png.InterlaceMethod;
    027import org.apache.commons.imaging.formats.png.PngColorType;
    028
    029public final class PngChunkIhdr extends PngChunk {
    030
    031    private final int width;
    032    private final int height;
    033    private final int bitDepth;
    034    private final PngColorType pngColorType;
    035    private final int compressionMethod;
    036    private final int filterMethod;
    037    private final InterlaceMethod interlaceMethod;
    038
    039    public PngChunkIhdr(final int length, final int chunkType, final int crc, final byte[] bytes) throws ImagingException, IOException {
    040        super(length, chunkType, crc, bytes);
    041
    042        final ByteArrayInputStream is = new ByteArrayInputStream(bytes);
    043        width = read4Bytes("Width", is, "Not a Valid PNG File: IHDR Corrupt", getByteOrder());
    044        height = read4Bytes("Height", is, "Not a Valid PNG File: IHDR Corrupt", getByteOrder());
    045        bitDepth = readByte("BitDepth", is, "Not a Valid PNG File: IHDR Corrupt");
    046        final int type = readByte("ColorType", is, "Not a Valid PNG File: IHDR Corrupt");
    047        pngColorType = PngColorType.getColorType(type);
    048        if (getPngColorType() == null) {
    049            throw new ImagingException("PNG: unknown color type: " + type);
    050        }
    051        compressionMethod = readByte("CompressionMethod", is, "Not a Valid PNG File: IHDR Corrupt");
    052        filterMethod = readByte("FilterMethod", is, "Not a Valid PNG File: IHDR Corrupt");
    053        final int method = readByte("InterlaceMethod", is, "Not a Valid PNG File: IHDR Corrupt");
    054        if (method < 0 || method >= InterlaceMethod.values().length) {
    055            throw new ImagingException("PNG: unknown interlace method: " + method);
    056        }
    057        interlaceMethod = InterlaceMethod.values()[method];
    058    }
    059
    060    public int getBitDepth() {
    061        return bitDepth;
    062    }
    063
    064    public int getCompressionMethod() {
    065        return compressionMethod;
    066    }
    067
    068    public int getFilterMethod() {
    069        return filterMethod;
    070    }
    071
    072    public int getHeight() {
    073        return height;
    074    }
    075
    076    public InterlaceMethod getInterlaceMethod() {
    077        return interlaceMethod;
    078    }
    079
    080    public PngColorType getPngColorType() {
    081        return pngColorType;
    082    }
    083
    084    public int getWidth() {
    085        return width;
    086    }
    087}