/* * $Id: Png.java,v 1.34 2002/08/23 08:59:33 blowagie Exp $ * $Name:  $ * * Copyright 1999, 2000, 2001, 2002 by Bruno Lowagie and Paulo Soares. * * The contents of this file are subject to the Mozilla Public License Version 1.1 * (the "License"); you may not use this file except in compliance with the License. * You may obtain a copy of the License at http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the License. * * The Original Code is 'iText, a free JAVA-PDF library'. * * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie. * All Rights Reserved. * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved. * * Contributor(s): all the names of the contributors are added in the source code * where applicable. * * Alternatively, the contents of this file may be used under the terms of the * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the * provisions of LGPL are applicable instead of those above.  If you wish to * allow use of your version of this file only under the terms of the LGPL * License and not to allow others to use your version of this file under * the MPL, indicate your decision by deleting the provisions above and * replace them with the notice and other provisions required by the LGPL. * If you do not delete the provisions above, a recipient may use your version * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE. * * This library is free software; you can redistribute it and/or modify it * under the terms of the MPL as stated above or under the terms of the GNU * Library General Public License as published by the Free Software Foundation; * either version 2 of the License, or any later version. * * This library is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more * details. * * If you didn't download this code from the following link, you should check if * you aren't using an obsolete version: * http://www.lowagie.com/iText/ */package com.lowagie.text;import java.io.InputStream;import java.io.IOException;import java.net.MalformedURLException;import java.net.URL;/** * An <CODE>Png</CODE> is the representation of a graphic element (PNG) * that has to be inserted into the document * * @see		Element * @see		Image * @see		Gif * @see		Jpeg */public class Png extends Image implements Element {        // public static final membervariables    /** Some PNG specific values. */    public static final int[] PNGID = {137, 80, 78, 71, 13, 10, 26, 10};    /** A PNG marker. */    public static final String IHDR = "IHDR";    /** A PNG marker. */    public static final String PLTE = "PLTE";    /** A PNG marker. */    public static final String IDAT = "IDAT";    /** A PNG marker. */    public static final String IEND = "IEND";    /** A PNG marker. */    public static final String tRNS = "tRNS";    /** A PNG marker. */    public static final String pHYs = "pHYs";        // Constructors    Png(Image image) {        super(image);    }    /** * Constructs a <CODE>Png</CODE>-object, using an <VAR>url</VAR>. * * @param		url			the <CODE>URL</CODE> where the image can be found. */        public Png(URL url) throws BadElementException, IOException {        super(url);        processParameters();    }    /** * Constructs a <CODE>Png</CODE>-object, using an <VAR>url</VAR>. * * @param		url			the <CODE>URL</CODE> where the image can be found. * @deprecated	use Image.getInstance(...) to create an Image */        public Png(URL url, float width, float height) throws BadElementException, IOException {        this(url);        scaledWidth = width;        scaledHeight = height;    }    /** * Constructs a <CODE>Png</CODE>-object, using a <VAR>filename</VAR>. * * @param		filename	a <CODE>String</CODE>-representation of the file that contains the Image. * @deprecated	use Image.getInstance(...) to create an Image */        public Png(String filename) throws MalformedURLException, BadElementException, IOException {        this(Image.toURL(filename));    }    /** * Constructs a <CODE>Png</CODE>-object, using a <VAR>filename</VAR>. * * @param		filename	a <CODE>String</CODE>-representation of the file that contains the Image. * @deprecated	use Image.getInstance(...) to create an Image */        public Png(String filename, float width, float height) throws MalformedURLException, BadElementException, IOException {        this(Image.toURL(filename), width, height);    }    /** * Constructs a <CODE>Png</CODE>-object from memory. * * @param		img			the memory image. */        public Png(byte[] img) throws BadElementException, IOException {        super((URL)null);        rawData = img;        processParameters();    }    /** * Constructs a <CODE>Png</CODE>-object from memory. * * @param		img			the memory image. */        public Png(byte[] img, float width, float height) throws BadElementException, IOException {        this(img);        scaledWidth = width;        scaledHeight = height;    }        // private methods    /** * Gets an <CODE>int</CODE> from an <CODE>InputStream</CODE>. * * @param		is      an <CODE>InputStream</CODE> * @return		the value of an <CODE>int</CODE> */        public static final int getInt(InputStream is) throws IOException {        return (is.read() << 24) + (is.read() << 16) + (is.read() << 8) + is.read();    }    /** * Gets a <CODE>word</CODE> from an <CODE>InputStream</CODE>. * * @param		is      an <CODE>InputStream</CODE> * @return		the value of an <CODE>int</CODE> */        public static final int getWord(InputStream is) throws IOException {        return (is.read() << 8) + is.read();    }    /** * Gets a <CODE>String</CODE> from an <CODE>InputStream</CODE>. * * @param		is      an <CODE>InputStream</CODE> * @return		the value of an <CODE>int</CODE> */        public static final String getString(InputStream is) throws IOException {        StringBuffer buf = new StringBuffer();        for (int i = 0; i < 4; i++) {            buf.append((char)is.read());        }        return buf.toString();    }        // private methods    /** * This method checks if the image is a valid PNG and processes some parameters. */        private void processParameters() throws BadElementException, IOException {        type = PNG;        InputStream is = null;        try {            String errorID;            if (rawData == null){                is = url.openStream();                errorID = url.toString();            }            else{                is = new java.io.ByteArrayInputStream(rawData);                errorID = "Byte array";            }            for (int i = 0; i < PNGID.length; i++) {                if (PNGID[i] != is.read())	{                    throw new BadElementException(errorID + " is not a valid PNG-file.");                }            }            while(true) {                int len = getInt(is);                String id = getString(is);                if (IHDR.equals(id)) {                    scaledWidth = getInt(is);                    setRight(scaledWidth);                    scaledHeight = getInt(is);                    setTop(scaledHeight);                    skip(is, len + 4 - 8);                    continue;                }                if (pHYs.equals(id)) {                    int dx = getInt(is);                    int dy = getInt(is);                    int unit = is.read();                    if (unit == 1) {                        dpiX = (int)((float)dx * 0.0254f + 0.5f);                        dpiY = (int)((float)dy * 0.0254f + 0.5f);                    }                    skip(is, len + 4 - 9);                    continue;                }                if (IDAT.equals(id) || IEND.equals(id)) {                    break;                }                skip(is, len + 4);            }        }        finally {            if (is != null) {                is.close();            }            plainWidth = width();            plainHeight = height();        }    }}