calloutemitter.java

jboss规则引擎

package com.nwalsh.saxon;

import java.util.Stack;
import java.util.StringTokenizer;
import org.xml.sax.*;
import org.w3c.dom.*;
import javax.xml.transform.TransformerException;
import com.icl.saxon.Controller;
import com.icl.saxon.om.NamePool;
import com.icl.saxon.output.Emitter;
import com.icl.saxon.tree.AttributeCollection;

/**
 * <p>Saxon extension to decorate a result tree fragment with callouts.</p>
 *
 * <p>$Id: CalloutEmitter.java 5907 2006-04-27 08:26:47Z xmldoc $</p>
 *
 * <p>Copyright (C) 2000 Norman Walsh.</p>
 *
 * <p>This class provides the guts of a
 * <a href="http://saxon.sourceforge.net/">Saxon 6.*</a>
 * implementation of callouts for verbatim environments. (It is used
 * by the Verbatim class.)</p>
 *
 * <p>The general design is this: the stylesheets construct a result tree
 * fragment for some verbatim environment. The Verbatim class initializes
 * a CalloutEmitter with information about the callouts that should be applied
 * to the verbatim environment in question. Then the result tree fragment
 * is "replayed" through the CalloutEmitter; the CalloutEmitter builds a
 * new result tree fragment from this event stream, decorated with callouts,
 * and that is returned.</p>
 *
 * <p><b>Change Log:</b></p>
 * <dl>
 * <dt>1.0</dt>
 * <dd><p>Initial release.</p></dd>
 * </dl>
 *
 * @see Verbatim
 *
 * @author Norman Walsh
 * <a href="mailto:[e-mail]">[e-mail]</a>
 *
 * @version $Id: CalloutEmitter.java 5907 2006-04-27 08:26:47Z xmldoc $
 *
 */
public class CalloutEmitter extends CopyEmitter {
  /** A stack for the preserving information about open elements. */
  protected Stack elementStack = null;

  /** A stack for holding information about temporarily closed elements. */
  protected Stack tempStack = null;

  /** Is the next element absolutely the first element in the fragment? */
  protected boolean firstElement = false;

  /** The FO namespace name. */
  protected static String foURI = "http://www.w3.org/1999/XSL/Format";

  /** The XHTML namespace name. */
  protected static String xhURI = "http://www.w3.org/1999/xhtml";

  /** The default column for callouts that specify only a line. */
  protected int defaultColumn = 60;

  /** Is the stylesheet currently running an FO stylesheet? */
  protected boolean foStylesheet = false;

  /** The current line number. */
  private static int lineNumber = 0;

  /** The current column number. */
  private static int colNumber = 0;

  /** The (sorted) array of callouts obtained from the areaspec. */
  private static Callout callout[] = null;

  /** The number of callouts in the callout array. */
  private static int calloutCount = 0;

  /** A pointer used to keep track of our position in the callout array. */
  private static int calloutPos = 0;

  /** The FormatCallout object to use for formatting callouts. */
  private static FormatCallout fCallout = null;

  /** <p>Constructor for the CalloutEmitter.</p>
   *
   * @param controller
   * @param namePool The name pool to use for constructing elements and attributes.
   * @param defaultColumn The default column for callouts.
   * @param foStylesheet Is this an FO stylesheet?
   * @param fCallout
   */
  public CalloutEmitter(Controller controller,
			NamePool namePool,
			int defaultColumn,
			boolean foStylesheet,
			FormatCallout fCallout) {
    super(controller, namePool);
    elementStack = new Stack();
    firstElement = true;

    this.defaultColumn = defaultColumn;
    this.foStylesheet = foStylesheet;
    this.fCallout = fCallout;
  }

  /**
   * <p>Examine the areaspec and determine the number and position of 
   * callouts.</p>
   *
   * <p>The <code><a href="http://docbook.org/tdg/html/areaspec.html">areaspecNodeSet</a></code>
   * is examined and a sorted list of the callouts is constructed.</p>
   *
   * <p>This data structure is used to augment the result tree fragment
   * with callout bullets.</p>
   *
   * @param areaspecNodeList The source document &lt;areaspec&gt; element.
   */
  public void setupCallouts (NodeList areaspecNodeList) {
    callout = new Callout[10];
    calloutCount = 0;
    calloutPos = 0;
    lineNumber = 1;
    colNumber = 1;

    // First we walk through the areaspec to calculate the position
    // of the callouts
    //  <areaspec>
    //  <areaset id="ex.plco.const" coords="">
    //    <area id="ex.plco.c1" coords="4"/>
    //    <area id="ex.plco.c2" coords="8"/>
    //  </areaset>
    //  <area id="ex.plco.ret" coords="12"/>
    //  <area id="ex.plco.dest" coords="12"/>
    //  </areaspec>
    int pos = 0;
    int coNum = 0;
    boolean inAreaSet = false;
    Node areaspec = areaspecNodeList.item(0);
    NodeList children = areaspec.getChildNodes();

    for (int count = 0; count < children.getLength(); count++) {
      Node node = children.item(count);
      if (node.getNodeType() == Node.ELEMENT_NODE) {
	if (node.getNodeName().equalsIgnoreCase("areaset")) {
	  coNum++;
	  NodeList areas = node.getChildNodes();
	  for (int acount = 0; acount < areas.getLength(); acount++) {
	    Node area = areas.item(acount);
	    if (area.getNodeType() == Node.ELEMENT_NODE) {
	      if (area.getNodeName().equalsIgnoreCase("area")) {
		addCallout(coNum, area, defaultColumn);
	      } else {
		System.out.println("Unexpected element in areaset: "
				   + area.getNodeName());
	      }
	    }
	  }
	} else if (node.getNodeName().equalsIgnoreCase("area")) {
	  coNum++;
	  addCallout(coNum, node, defaultColumn);
	} else {
	  System.out.println("Unexpected element in areaspec: "
			     + node.getNodeName());
	}
      }
    }

    // Now sort them
    java.util.Arrays.sort(callout, 0, calloutCount);
  }

  /** Process characters. */
  public void characters(char[] chars, int start, int len)
    throws TransformerException {

    // If we hit characters, then there's no first element...
    firstElement = false;

    if (lineNumber == 0) {
      // if there are any text nodes, there's at least one line
      lineNumber++;
      colNumber = 1;
    }

    // Walk through the text node looking for callout positions
    char[] newChars = new char[len];
    int pos = 0;
    for (int count = start; count < start+len; count++) {
      if (calloutPos < calloutCount
	  && callout[calloutPos].getLine() == lineNumber
	  && callout[calloutPos].getColumn() == colNumber) {
	if (pos > 0) {
	  rtfEmitter.characters(newChars, 0, pos);
	  pos = 0;
	}

	closeOpenElements(rtfEmitter);

	while (calloutPos < calloutCount
	       && callout[calloutPos].getLine() == lineNumber
	       && callout[calloutPos].getColumn() == colNumber) {
	  fCallout.formatCallout(rtfEmitter, callout[calloutPos]);
	  calloutPos++;
	}

	openClosedElements(rtfEmitter);
      }

      if (chars[count] == '\n') {
	// What if we need to pad this line?
	if (calloutPos < calloutCount
	    && callout[calloutPos].getLine() == lineNumber
	    && callout[calloutPos].getColumn() > colNumber) {

	  if (pos > 0) {
	    rtfEmitter.characters(newChars, 0, pos);
	    pos = 0;
	  }

	  closeOpenElements(rtfEmitter);

	  while (calloutPos < calloutCount
		 && callout[calloutPos].getLine() == lineNumber
		 && callout[calloutPos].getColumn() > colNumber) {
	    formatPad(callout[calloutPos].getColumn() - colNumber);
	    colNumber = callout[calloutPos].getColumn();
	    while (calloutPos < calloutCount
		   && callout[calloutPos].getLine() == lineNumber
		   && callout[calloutPos].getColumn() == colNumber) {
	      fCallout.formatCallout(rtfEmitter, callout[calloutPos]);
	      calloutPos++;
	    }
	  }

	  openClosedElements(rtfEmitter);
	}

	lineNumber++;
	colNumber = 1;
      } else {
	colNumber++;
      }
      newChars[pos++] = chars[count];
    }

    if (pos > 0) {
      rtfEmitter.characters(newChars, 0, pos);
    }
  }

  /**
   * <p>Add blanks to the result tree fragment.</p>
   *
   * <p>This method adds <tt>numBlanks</tt> to the result tree fragment.
   * It's used to pad lines when callouts occur after the last existing
   * characater in a line.</p>
   *
   * @param numBlanks The number of blanks to add.
   */
  protected void formatPad(int numBlanks) {
    char chars[] = new char[numBlanks];
    for (int count = 0; count < numBlanks; count++) {
      chars[count] = ' ';
    }