com.nwalsh.saxon

Class CalloutEmitter


public class CalloutEmitter
extends CopyEmitter

Saxon extension to decorate a result tree fragment with callouts.

$Id: CalloutEmitter.java 5907 2006-04-27 08:26:47Z xmldoc $

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:

See Also:
Verbatim

Field Summary

protected int
defaultColumn
The default column for callouts that specify only a line.
protected 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 String
foURI
The FO namespace name.
protected Stack
tempStack
A stack for holding information about temporarily closed elements.
protected static String
xhURI
The XHTML namespace name.

Fields inherited from class com.nwalsh.saxon.CopyEmitter

namePool, rtf, rtfEmitter

Constructor Summary

CalloutEmitter(Controller controller, NamePool namePool, int defaultColumn, boolean foStylesheet, FormatCallout fCallout)
Constructor for the CalloutEmitter.

Method Summary

protected void
addCallout(int coNum, 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.

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(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

characters, comment, endDocument, endElement, getResultTreeFragment, processingInstruction, setDocumentLocator, setEscaping, setNamePool, setUnparsedEntity, setWriter, startDocument, startElement

Field Details

defaultColumn

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

elementStack

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

firstElement

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

foStylesheet

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

foURI

protected static String foURI
The FO namespace name.

tempStack

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

xhURI

protected static String xhURI
The XHTML namespace name.

Constructor Details

CalloutEmitter

public CalloutEmitter(Controller controller,
                      NamePool namePool,
                      int defaultColumn,
                      boolean foStylesheet,
                      FormatCallout fCallout)
Constructor for the CalloutEmitter.
Parameters:
controller -
namePool - The name pool to use for constructing elements and attributes.
defaultColumn - The default column for callouts.
foStylesheet - Is this an FO stylesheet?
fCallout -

Method Details

addCallout

protected void addCallout(int coNum,
                          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.

characters

public void characters(char[] chars,
                       int start,
                       int len)
            throws TransformerException
Process characters.
Overrides:
characters in interface CopyEmitter

endElement

public void endElement(int nameCode)
            throws TransformerException
Process end element events.
Overrides:
endElement in interface CopyEmitter

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.

setupCallouts

public void setupCallouts(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.

Parameters:
areaspecNodeList - The source document <areaspec> element.

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.

startElement

public void startElement(int nameCode,
                         org.xml.sax.Attributes attributes,
                         int[] namespaces,
                         int nscount)
            throws TransformerException
Process start element events.
Overrides:
startElement in interface CopyEmitter