verbatim.java

Java的面向对象数据库系统的源代码

// Verbatim.java - Xalan extensions supporting DocBook verbatim environments

package com.nwalsh.xalan;

import java.util.Stack;
import java.util.StringTokenizer;

import org.xml.sax.*;
import org.xml.sax.helpers.AttributesImpl;
import org.w3c.dom.*;
import org.w3c.dom.traversal.NodeIterator;
import org.apache.xerces.dom.*;

import org.apache.xpath.objects.XObject;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.NodeSet;
import org.apache.xpath.DOMHelper;
import org.apache.xalan.extensions.XSLProcessorContext;
import org.apache.xalan.extensions.ExpressionContext;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xalan.templates.StylesheetRoot;
import org.apache.xalan.templates.ElemExtensionCall;
import org.apache.xalan.templates.OutputProperties;
import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xml.utils.DOMBuilder;
import org.apache.xml.utils.AttList;
import org.apache.xml.utils.QName;

import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.TransformerException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import com.nwalsh.xalan.Callout;
import com.nwalsh.xalan.Params;

/**
 * <p>Xalan extensions supporting DocBook verbatim environments</p>
 *
 * <p>$Id: Verbatim.java,v 1.4 2001/07/15 20:07:49 nwalsh Exp $</p>
 *
 * <p>Copyright (C) 2001 Norman Walsh.</p>
 *
 * <p>This class provides a
 * <a href="http://xml.apache.org/xalan">Xalan</a>
 * implementation of two features that would be impractical to
 * implement directly in XSLT: line numbering and callouts.</p>
 *
 * <p><b>Line Numbering</b></p>
 * <p>The <tt>numberLines</tt> family of functions takes a result tree
 * fragment (assumed to contain the contents of a formatted verbatim
 * element in DocBook: programlisting, screen, address, literallayout,
 * or synopsis) and returns a result tree fragment decorated with
 * line numbers.</p>
 *
 * <p><b>Callouts</b></p>
 * <p>The <tt>insertCallouts</tt> family of functions takes an
 * <tt>areaspec</tt> and a result tree fragment
 * (assumed to contain the contents of a formatted verbatim
 * element in DocBook: programlisting, screen, address, literallayout,
 * or synopsis) and returns a result tree fragment decorated with
 * callouts.</p>
 *
 * <p><b>Change Log:</b></p>
 * <dl>
 * <dt>1.0</dt>
 * <dd><p>Initial release.</p></dd>
 * </dl>
 *
 * @author Norman Walsh
 * <a href="mailto:[e-mail]">[e-mail]</a>
 *
 * @version $Id: Verbatim.java,v 1.4 2001/07/15 20:07:49 nwalsh Exp $
 *
 */
public class Verbatim {
  /** A stack to hold the open elements while walking through a RTF. */
  private Stack elementStack = null;
  /** A stack to hold the temporarily closed elements. */
  private Stack tempStack = null;
  /** The current line number. */
  private int lineNumber = 0;
  /** The current column number. */
  private int colNumber = 0;
  /** The modulus for line numbering (every 'modulus' line is numbered). */
  private int modulus = 0;
  /** The width (in characters) of line numbers (for padding). */
  private int width = 0;
  /** The separator between the line number and the verbatim text. */
  private String separator = "";
  /** The (sorted) array of callouts obtained from the areaspec. */
  private Callout callout[] = null;
  /** The number of callouts in the callout array. */
  private int calloutCount = 0;
  /** A pointer used to keep track of our position in the callout array. */
  private int calloutPos = 0;
  /** The path to use for graphical callout decorations. */
  private String graphicsPath = null;
  /** The extension to use for graphical callout decorations. */
  private String graphicsExt = null;
  /** The largest callout number that can be represented graphically. */
  private int graphicsMax = 10;
  /** Should graphic callouts use fo:external-graphics or imgs. */
  private boolean graphicsFO = false;

  private static final String foURI = "http://www.w3.org/1999/XSL/Format";
  private static final String xhURI = "http://www.w3.org/1999/xhtml";

  /**
   * <p>Constructor for Verbatim</p>
   *
   * <p>All of the methods are static, so the constructor does nothing.</p>
   */
  public Verbatim() {
  }

  /**
   * <p>Number lines in a verbatim environment.</p>
   *
   * <p>This method adds line numbers to a result tree fragment. Each
   * newline that occurs in a text node is assumed to start a new line.
   * The first line is always numbered, every subsequent xalanMod line
   * is numbered (so if xalanMod=5, lines 1, 5, 10, 15, etc. will be
   * numbered. If there are fewer than xalanMod lines in the environment,
   * every line is numbered.</p>
   *
   * <p>xalanMod is taken from the $linenumbering.everyNth parameter.</p>
   *
   * <p>Every line number will be right justified in a string xalanWidth
   * characters long. If the line number of the last line in the
   * environment is too long to fit in the specified width, the width
   * is automatically increased to the smallest value that can hold the
   * number of the last line. (In other words, if you specify the value 2
   * and attempt to enumerate the lines of an environment that is 100 lines
   * long, the value 3 will automatically be used for every line in the
   * environment.)</p>
   *
   * <p>xalanWidth is taken from the $linenumbering.width parameter.</p>
   *
   * <p>The xalanSep string is inserted between the line
   * number and the original program listing. Lines that aren't numbered
   * are preceded by a xalanWidth blank string and the separator.</p>
   *
   * <p>xalanSep is taken from the $linenumbering.separator parameter.</p>
   *
   * <p>If inline markup extends across line breaks, markup changes are
   * required. All the open elements are closed before the line break and
   * "reopened" afterwards. The reopened elements will have the same
   * attributes as the originals, except that 'name' and 'id' attributes
   * are not duplicated.</p>
   *
   * @param xalanRTF The result tree fragment of the verbatim environment.
   *
   * @return The modified result tree fragment.
   */
  public DocumentFragment numberLines (ExpressionContext context,
				       NodeIterator xalanNI) {

    int xalanMod = Params.getInt(context, "linenumbering.everyNth");
    int xalanWidth = Params.getInt(context, "linenumbering.width");
    String xalanSep = Params.getString(context, "linenumbering.separator");

    DocumentFragment xalanRTF = (DocumentFragment) xalanNI.nextNode();
    int numLines = countLineBreaks(xalanRTF) + 1;

    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder docBuilder = null;

    try {
      docBuilder = docFactory.newDocumentBuilder();
    } catch (ParserConfigurationException e) {
      System.out.println("PCE!");
      return xalanRTF;
    }
    Document doc = docBuilder.newDocument();
    DocumentFragment df = doc.createDocumentFragment();
    DOMBuilder db = new DOMBuilder(doc, df);

    elementStack = new Stack();
    lineNumber = 0;
    modulus = numLines < xalanMod ? 1 : xalanMod;
    width = xalanWidth;
    separator = xalanSep;

    double log10numLines = Math.log(numLines) / Math.log(10);

    if (width < log10numLines + 1) {
      width = (int) Math.floor(log10numLines + 1);
    }

    lineNumberFragment(db, xalanRTF);
    return df;
  }

  /**
   * <p>Count the number of lines in a verbatim environment.</p>
   *
   * <p>This method walks over the nodes of a DocumentFragment and
   * returns the number of lines breaks that it contains.</p>
   *
   * @param node The root of the tree walk over.
   */
  private int countLineBreaks(Node node) {
    int numLines = 0;

    if (node.getNodeType() == Node.DOCUMENT_FRAGMENT_NODE
	|| node.getNodeType() == Node.DOCUMENT_NODE
	|| node.getNodeType() == Node.ELEMENT_NODE) {
      Node child = node.getFirstChild();
      while (child != null) {
	numLines += countLineBreaks(child);
	child = child.getNextSibling();
      }
    } else if (node.getNodeType() == Node.TEXT_NODE) {
      String text = node.getNodeValue();

      // Walk through the text node looking for newlines
      int pos = 0;
      for (int count = 0; count < text.length(); count++) {
	if (text.charAt(count) == '\n') {
	  numLines++;
	}
      }
    } else {
      // nop
    }

    return numLines;
  }

  /**
   * <p>Build a DocumentFragment with numbered lines.</p>
   *
   * <p>This is the method that actually does the work of numbering
   * lines in a verbatim environment. It recursively walks through a
   * tree of nodes, copying the structure into the rtf. Text nodes
   * are examined for new lines and modified as requested by the
   * global line numbering parameters.</p>
   *
   * <p>When called, rtf should be an empty DocumentFragment and node
   * should be the first child of the result tree fragment that contains
   * the existing, formatted verbatim text.</p>
   *
   * @param rtf The resulting verbatim environment with numbered lines.
   * @param node The root of the tree to copy.
   */
  private void lineNumberFragment(DOMBuilder rtf,
				  Node node) {
    try {
      if (node.getNodeType() == Node.DOCUMENT_FRAGMENT_NODE
	  || node.getNodeType() == Node.DOCUMENT_NODE) {
	Node child = node.getFirstChild();
	while (child != null) {
	  lineNumberFragment(rtf, child);
	  child = child.getNextSibling();
	}
      } else if (node.getNodeType() == Node.ELEMENT_NODE) {
	String ns = node.getNamespaceURI();
	String localName = node.getLocalName();
	String name = ((Element) node).getTagName();

	rtf.startElement(ns, localName, name,
			 copyAttributes((Element) node));

	elementStack.push(node);

	Node child = node.getFirstChild();
	while (child != null) {
	  lineNumberFragment(rtf, child);
	  child = child.getNextSibling();
	}
      } else if (node.getNodeType() == Node.TEXT_NODE) {
	String text = node.getNodeValue();

	if (lineNumber == 0) {
	  // The first line is always numbered
	  formatLineNumber(rtf, ++lineNumber);
	}

	// Walk through the text node looking for newlines
	char chars[] = text.toCharArray();
	int pos = 0;
	for (int count = 0; count < text.length(); count++) {
	  if (text.charAt(count) == '\n') {
	    // This is the tricky bit; if we find a newline, make sure
	    // it doesn't occur inside any markup.

	    if (pos > 0) {
	      rtf.characters(chars, 0, pos);
	      pos = 0;
	    }

	    closeOpenElements(rtf);

	    // Copy the newline to the output
	    chars[pos++] = text.charAt(count);
	    rtf.characters(chars, 0, pos);
	    pos = 0;

	    // Add the line number
	    formatLineNumber(rtf, ++lineNumber);

	    openClosedElements(rtf);
	  } else {
	    chars[pos++] = text.charAt(count);
	  }
	}