Java tutorial
/* * $Id: DocWriter.java 3937 2009-05-27 12:56:48Z blowagie $ * * Copyright 1999, 2000, 2001, 2002 by Bruno Lowagie. * * 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.BufferedOutputStream; import java.io.IOException; import java.io.OutputStream; import java.util.Iterator; import java.util.Properties; import com.lowagie.text.pdf.OutputStreamCounter; /** * An abstract <CODE>Writer</CODE> class for documents. * <P> * <CODE>DocWriter</CODE> is the abstract class of several writers such * as <CODE>PdfWriter</CODE> and <CODE>HtmlWriter</CODE>. * A <CODE>DocWriter</CODE> can be added as a <CODE>DocListener</CODE> * to a certain <CODE>Document</CODE> by getting an instance (see method * <CODE>getInstance()</CODE> in the specific writer-classes). * Every <CODE>Element</CODE> added to the original <CODE>Document</CODE> * will be written to the <CODE>OutputStream</CODE> of the listening * <CODE>DocWriter</CODE>. * * @see Document * @see DocListener */ public abstract class DocWriter implements DocListener { /** This is some byte that is often used. */ public static final byte NEWLINE = (byte) '\n'; /** This is some byte that is often used. */ public static final byte TAB = (byte) '\t'; /** This is some byte that is often used. */ public static final byte LT = (byte) '<'; /** This is some byte that is often used. */ public static final byte SPACE = (byte) ' '; /** This is some byte that is often used. */ public static final byte EQUALS = (byte) '='; /** This is some byte that is often used. */ public static final byte QUOTE = (byte) '\"'; /** This is some byte that is often used. */ public static final byte GT = (byte) '>'; /** This is some byte that is often used. */ public static final byte FORWARD = (byte) '/'; // membervariables /** The pageSize. */ protected Rectangle pageSize; /** This is the document that has to be written. */ protected Document document; /** The outputstream of this writer. */ protected OutputStreamCounter os; /** Is the writer open for writing? */ protected boolean open = false; /** Do we have to pause all writing actions? */ protected boolean pause = false; /** Closes the stream on document close */ protected boolean closeStream = true; // constructor protected DocWriter() { } /** * Constructs a <CODE>DocWriter</CODE>. * * @param document The <CODE>Document</CODE> that has to be written * @param os The <CODE>OutputStream</CODE> the writer has to write to. */ protected DocWriter(Document document, OutputStream os) { this.document = document; this.os = new OutputStreamCounter(new BufferedOutputStream(os)); } // implementation of the DocListener methods /** * Signals that an <CODE>Element</CODE> was added to the <CODE>Document</CODE>. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class. * * @param element A high level object to add * @return <CODE>false</CODE> * @throws DocumentException when a document isn't open yet, or has been closed */ public boolean add(Element element) throws DocumentException { return false; } /** * Signals that the <CODE>Document</CODE> was opened. */ public void open() { open = true; } /** * Sets the pagesize. * * @param pageSize the new pagesize * @return a <CODE>boolean</CODE> */ public boolean setPageSize(Rectangle pageSize) { this.pageSize = pageSize; return true; } /** * Sets the margins. * <P> * This does nothing. Has to be overridden if needed. * * @param marginLeft the margin on the left * @param marginRight the margin on the right * @param marginTop the margin on the top * @param marginBottom the margin on the bottom * @return <CODE>false</CODE> */ public boolean setMargins(float marginLeft, float marginRight, float marginTop, float marginBottom) { return false; } /** * Signals that an new page has to be started. * <P> * This does nothing. Has to be overridden if needed. * * @return <CODE>true</CODE> if the page was added, <CODE>false</CODE> if not. */ public boolean newPage() { if (!open) { return false; } return true; } /** * Changes the header of this document. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * headers. * * @param header the new header */ public void setHeader(HeaderFooter header) { } /** * Resets the header of this document. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * headers. */ public void resetHeader() { } /** * Changes the footer of this document. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * footers. * * @param footer the new footer */ public void setFooter(HeaderFooter footer) { } /** * Resets the footer of this document. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * footers. */ public void resetFooter() { } /** * Sets the page number to 0. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * pagenumbers. */ public void resetPageCount() { } /** * Sets the page number. * <P> * This method should be overridden in the specific <CODE>DocWriter<CODE> classes * derived from this abstract class if they actually support the use of * pagenumbers. * * @param pageN the new page number */ public void setPageCount(int pageN) { } /** * Signals that the <CODE>Document</CODE> was closed and that no other * <CODE>Elements</CODE> will be added. */ public void close() { open = false; try { os.flush(); if (closeStream) os.close(); } catch (IOException ioe) { throw new ExceptionConverter(ioe); } } // methods /** Converts a <CODE>String</CODE> into a <CODE>Byte</CODE> array * according to the ISO-8859-1 codepage. * @param text the text to be converted * @return the conversion result */ public static final byte[] getISOBytes(String text) { if (text == null) return null; int len = text.length(); byte b[] = new byte[len]; for (int k = 0; k < len; ++k) b[k] = (byte) text.charAt(k); return b; } /** * Let the writer know that all writing has to be paused. */ public void pause() { pause = true; } /** * Checks if writing is paused. * * @return <CODE>true</CODE> if writing temporarily has to be paused, <CODE>false</CODE> otherwise. */ public boolean isPaused() { return pause; } /** * Let the writer know that writing may be resumed. */ public void resume() { pause = false; } /** * Flushes the <CODE>BufferedOutputStream</CODE>. */ public void flush() { try { os.flush(); } catch (IOException ioe) { throw new ExceptionConverter(ioe); } } /** * Writes a <CODE>String</CODE> to the <CODE>OutputStream</CODE>. * * @param string the <CODE>String</CODE> to write * @throws IOException */ protected void write(String string) throws IOException { os.write(getISOBytes(string)); } /** * Writes a number of tabs. * * @param indent the number of tabs to add * @throws IOException */ protected void addTabs(int indent) throws IOException { os.write(NEWLINE); for (int i = 0; i < indent; i++) { os.write(TAB); } } /** * Writes a key-value pair to the outputstream. * * @param key the name of an attribute * @param value the value of an attribute * @throws IOException */ protected void write(String key, String value) throws IOException { os.write(SPACE); write(key); os.write(EQUALS); os.write(QUOTE); write(value); os.write(QUOTE); } /** * Writes a starttag to the outputstream. * * @param tag the name of the tag * @throws IOException */ protected void writeStart(String tag) throws IOException { os.write(LT); write(tag); } /** * Writes an endtag to the outputstream. * * @param tag the name of the tag * @throws IOException */ protected void writeEnd(String tag) throws IOException { os.write(LT); os.write(FORWARD); write(tag); os.write(GT); } /** * Writes an endtag to the outputstream. * @throws IOException */ protected void writeEnd() throws IOException { os.write(SPACE); os.write(FORWARD); os.write(GT); } /** * Writes the markup attributes of the specified <CODE>MarkupAttributes</CODE> * object to the <CODE>OutputStream</CODE>. * @param markup a <CODE>Properties</CODE> collection to write. * @return true, if writing the markup attributes succeeded * @throws IOException */ protected boolean writeMarkupAttributes(Properties markup) throws IOException { if (markup == null) return false; Iterator attributeIterator = markup.keySet().iterator(); String name; while (attributeIterator.hasNext()) { name = String.valueOf(attributeIterator.next()); write(name, markup.getProperty(name)); } markup.clear(); return true; } /** Checks if the stream is to be closed on document close * @return true if the stream is closed on document close * */ public boolean isCloseStream() { return closeStream; } /** Sets the close state of the stream after document close * @param closeStream true if the stream is closed on document close * */ public void setCloseStream(boolean closeStream) { this.closeStream = closeStream; } /** * @see com.lowagie.text.DocListener#setMarginMirroring(boolean) */ public boolean setMarginMirroring(boolean MarginMirroring) { return false; } /** * @see com.lowagie.text.DocListener#setMarginMirroring(boolean) * @since 2.1.6 */ public boolean setMarginMirroringTopBottom(boolean MarginMirroring) { return false; } }