com.nwalsh.saxon
Class CalloutEmitter

java.lang.Object
  extended bycom.icl.saxon.output.Emitter
      extended bycom.nwalsh.saxon.CopyEmitter
          extended bycom.nwalsh.saxon.CalloutEmitter
All Implemented Interfaces:
javax.xml.transform.Result

public class CalloutEmitter
extends CopyEmitter

Saxon extension to decorate a result tree fragment with callouts.

$Id: CalloutEmitter.java,v 1.2 2002/03/21 13:27:51 nwalsh Exp $

Copyright (C) 2000 Norman Walsh.

This class provides the guts of a Saxon 6.* implementation of callouts for verbatim environments. (It is used by the Verbatim class.)

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.

Change Log:

1.0

Initial release.

Version:
$Id: CalloutEmitter.java,v 1.2 2002/03/21 13:27:51 nwalsh Exp $
Author:
Norman Walsh ndw@nwalsh.com
See Also:
Verbatim

Field Summary
protected  int defaultColumn
          The default column for callouts that specify only a line.
protected  java.util.Stack elementStack
          A stack for the preserving information about open elements.
protected  boolean firstElement
          Is the next element absolutely the first element in the fragment?
protected  boolean foStylesheet
          Is the stylesheet currently running an FO stylesheet?
protected static java.lang.String foURI
          The FO namespace name.
protected  java.util.Stack tempStack
          A stack for holding information about temporarily closed elements.
protected static java.lang.String xhURI
          The XHTML namespace name.
 
Fields inherited from class com.nwalsh.saxon.CopyEmitter
namePool, rtf, rtfEmitter
 
Fields inherited from class com.icl.saxon.output.Emitter
locator, outputProperties, outputStream, systemId, writer
 
Fields inherited from interface javax.xml.transform.Result
PI_DISABLE_OUTPUT_ESCAPING, PI_ENABLE_OUTPUT_ESCAPING
 
Constructor Summary
CalloutEmitter(Controller controller, NamePool namePool, int defaultColumn, boolean foStylesheet, FormatCallout fCallout)
          Constructor for the CalloutEmitter.
 
Method Summary
protected  void addCallout(int coNum, org.w3c.dom.Node node, int defaultColumn)
          Add a callout to the global callout array
 void characters(char[] chars, int start, int len)
          Process characters.
 void endElement(int nameCode)
          Process end element events.
protected  void formatPad(int numBlanks)
          Add blanks to the result tree fragment.
 void setupCallouts(org.w3c.dom.NodeList areaspecNodeList)
          Examine the areaspec and determine the number and position of callouts.
protected  boolean skipThisElement(int nameCode)
          Protect the outer-most block wrapper.
 void startElement(int nameCode, org.xml.sax.Attributes attributes, int[] namespaces, int nscount)
          Process start element events.
 
Methods inherited from class com.nwalsh.saxon.CopyEmitter
comment, endDocument, getResultTreeFragment, processingInstruction, setDocumentLocator, setEscaping, setNamePool, setUnparsedEntity, setWriter, startDocument
 
Methods inherited from class com.icl.saxon.output.Emitter
getNamePool, getOutputProperties, getOutputStream, getSystemId, getWriter, makeEmitter, setOutputProperties, setOutputStream, setSystemId, usesWriter
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

elementStack

protected java.util.Stack elementStack
A stack for the preserving information about open elements.


tempStack

protected java.util.Stack tempStack
A stack for holding information about temporarily closed elements.


firstElement

protected boolean firstElement
Is the next element absolutely the first element in the fragment?


foURI

protected static java.lang.String foURI
The FO namespace name.


xhURI

protected static java.lang.String xhURI
The XHTML namespace name.


defaultColumn

protected int defaultColumn
The default column for callouts that specify only a line.


foStylesheet

protected boolean foStylesheet
Is the stylesheet currently running an FO stylesheet?

Constructor Detail

CalloutEmitter

public CalloutEmitter(Controller controller,
                      NamePool namePool,
                      int defaultColumn,
                      boolean foStylesheet,
                      FormatCallout fCallout)

Constructor for the CalloutEmitter.

Parameters:
namePool - The name pool to use for constructing elements and attributes.
defaultColumn - The default column for callouts.
foStylesheet - Is this an FO stylesheet?
Method Detail

setupCallouts

public void setupCallouts(org.w3c.dom.NodeList areaspecNodeList)

Examine the areaspec and determine the number and position of callouts.

The areaspecNodeSet is examined and a sorted list of the callouts is constructed.

This data structure is used to augment the result tree fragment with callout bullets.


characters

public void characters(char[] chars,
                       int start,
                       int len)
                throws javax.xml.transform.TransformerException
Process characters.

Overrides:
characters in class CopyEmitter
Throws:
javax.xml.transform.TransformerException

formatPad

protected void formatPad(int numBlanks)

Add blanks to the result tree fragment.

This method adds numBlanks to the result tree fragment. It's used to pad lines when callouts occur after the last existing characater in a line.

Parameters:
numBlanks - The number of blanks to add.

addCallout

protected void addCallout(int coNum,
                          org.w3c.dom.Node node,
                          int defaultColumn)

Add a callout to the global callout array

This method examines a callout area and adds it to the global callout array if it can be interpreted.

Only the linecolumn and linerange units are supported. If no unit is specifed, linecolumn is assumed. If only a line is specified, the callout decoration appears in the defaultColumn.

Parameters:
coNum - The callout number.
node - The area.
defaultColumn - The default column for callouts.

endElement

public void endElement(int nameCode)
                throws javax.xml.transform.TransformerException
Process end element events.

Overrides:
endElement in class CopyEmitter
Throws:
javax.xml.transform.TransformerException

startElement

public void startElement(int nameCode,
                         org.xml.sax.Attributes attributes,
                         int[] namespaces,
                         int nscount)
                  throws javax.xml.transform.TransformerException
Process start element events.

Overrides:
startElement in class CopyEmitter
Throws:
javax.xml.transform.TransformerException

skipThisElement

protected boolean skipThisElement(int nameCode)

Protect the outer-most block wrapper.

Open elements in the result tree fragment are closed and reopened around callouts (so that callouts don't appear inside links or other environments). But if the result tree fragment is a single block (a div or pre in HTML, an fo:block in FO), that outer-most block is treated specially.

This method returns true if the element in question is that outermost block.

Parameters:
nameCode - The name code for the element
Returns:
True if the element is the outer-most block, false otherwise.