// Verbatim.java - Saxon extensions supporting DocBook verbatim environments
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.expr.*;
import com.icl.saxon.om.*;
import com.icl.saxon.pattern.*;
import com.icl.saxon.Context;
import com.icl.saxon.tree.*;
import com.icl.saxon.functions.Extensions;
import com.nwalsh.saxon.NumberLinesEmitter;
import com.nwalsh.saxon.CalloutEmitter;
/**
* <p>Saxon extensions supporting DocBook verbatim environments</p>
*
* <p>$Id: Verbatim.java,v 1.2 2001/08/05 22:35:38 nwalsh Exp $</p>
*
* <p>Copyright (C) 2000 Norman Walsh.</p>
*
* <p>This class provides a
* <a href="http://users.iclway.co.uk/mhkay/saxon/">Saxon</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> method 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> method 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:ndw@nwalsh.com">ndw@nwalsh.com</a>
*
* @version $Id: Verbatim.java,v 1.2 2001/08/05 22:35:38 nwalsh Exp $
*
*/
public class Verbatim {
/** True if the stylesheet is producing formatting objects */
private static boolean foStylesheet = false;
/** The modulus for line numbering (every 'modulus' line is numbered). */
private static int modulus = 0;
/** The width (in characters) of line numbers (for padding). */
private static int width = 0;
/** The separator between the line number and the verbatim text. */
private static String separator = "";
/** True if callouts have been setup */
private static boolean calloutsSetup = false;
/** The default column for callouts that have only a line or line range */
private static int defaultColumn = 60;
/** The path to use for graphical callout decorations. */
private static String graphicsPath = null;
/** The extension to use for graphical callout decorations. */
private static String graphicsExt = null;
/** The largest callout number that can be represented graphically. */
private static int graphicsMax = 10;
/** The FormatCallout object to use for formatting callouts. */
private static FormatCallout fCallout = null;
/**
* <p>Constructor for Verbatim</p>
*
* <p>All of the methods are static, so the constructor does nothing.</p>
*/
public Verbatim() {
}
/**
* <p>Find the string value of a stylesheet variable or parameter</p>
*
* <p>Returns the string value of <code>varName</code> in the current
* <code>context</code>. Returns the empty string if the variable is
* not defined.</p>
*
* @param context The current stylesheet context
* @param varName The name of the variable (without the dollar sign)
*
* @return The string value of the variable
*/
protected static String getVariable(Context context, String varName) {
Value variable = null;
String varString = null;
try {
variable = Extensions.evaluate(context, "$" + varName);
varString = variable.asString();
return varString;
} catch (TransformerException te) {
System.out.println("Undefined variable: " + varName);
return "";
} catch (IllegalArgumentException iae) {
System.out.println("Undefined variable: " + varName);
return "";
}
}
/**
* <p>Setup the parameters associated with line numbering</p>
*
* <p>This method queries the stylesheet for the variables
* associated with line numbering. It is called automatically before
* lines are numbered. The context is used to retrieve the values,
* this allows templates to redefine these variables.</p>
*
* <p>The following variables are queried. If the variables do not
* exist, builtin defaults will be used (but you may also get a bunch
* of messages from the Java interpreter).</p>
*
* <dl>
* <dt><code>linenumbering.everyNth</code></dt>
* <dd>Specifies the lines that will be numbered. The first line is
* always numbered. (builtin default: 5).</dd>
* <dt><code>linenumbering.width</code></dt>
* <dd>Specifies the width of the numbers. If the specified width is too
* narrow for the largest number needed, it will automatically be made
* wider. (builtin default: 3).</dd>
* <dt><code>linenumbering.separator</code></dt>
* <dd>Specifies the string that separates line numbers from lines
* in the program listing. (builtin default: " ").</dd>
* <dt><code>stylesheet.result.type</code></dt>
* <dd>Specifies the stylesheet result type. The value is either 'fo'
* (for XSL Formatting Objects) or it isn't. (builtin default: html).</dd>
* </dl>
*
* @param context The current stylesheet context
*
*/
private static void setupLineNumbering(Context context) {
// Hardcoded defaults
modulus = 5;
width = 3;
separator = " ";
foStylesheet = false;
String varString = null;
// Get the modulus
varString = getVariable(context, "linenumbering.everyNth");
try {
modulus = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$linenumbering.everyNth is not a number: " + varString);
}
// Get the width
varString = getVariable(context, "linenumbering.width");
try {
width = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$linenumbering.width is not a number: " + varString);
}
// Get the separator
varString = getVariable(context, "linenumbering.separator");
separator = varString;
// Get the stylesheet type
varString = getVariable(context, "stylesheet.result.type");
foStylesheet = (varString.equals("fo"));
}
/**
* <p>Number lines in a verbatim environment</p>
*
* <p>The extension function expects the following variables to be
* available in the calling context: $linenumbering.everyNth,
* $linenumbering.width, $linenumbering.separator, and
* $stylesheet.result.type.</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 'everyNth' line
* is numbered (so if everyNth=5, lines 1, 5, 10, 15, etc. will be
* numbered. If there are fewer than everyNth lines in the environment,
* every line is numbered.</p>
*
* <p>Every line number will be right justified in a string 'width'
* 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>The 'separator' string is inserted between the line
* number and the original program listing. Lines that aren't numbered
* are preceded by a 'width' blank string and the separator.</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 if the stylesheet.result.type is "html" and
* 'id' attributes will not be duplicated if the result type is "fo".</p>
*
* @param rtf The result tree fragment of the verbatim environment.
*
* @return The modified result tree fragment.
*/
public static NodeSetValue numberLines (Context context,
NodeSetValue rtf_ns) {
FragmentValue rtf = (FragmentValue) rtf_ns;
setupLineNumbering(context);
try {
LineCountEmitter lcEmitter = new LineCountEmitter();
rtf.replay(lcEmitter);
int numLines = lcEmitter.lineCount();
int listingModulus = numLines < modulus ? 1 : modulus;
double log10numLines = Math.log(numLines) / Math.log(10);
int listingWidth = width < log10numLines+1
? (int) Math.floor(log10numLines + 1)
: width;
NamePool namePool = context.getController().getNamePool();
NumberLinesEmitter nlEmitter = new NumberLinesEmitter(namePool,
listingModulus,
listingWidth,
separator,
foStylesheet);
rtf.replay(nlEmitter);
return nlEmitter.getResultTreeFragment();
} catch (TransformerException e) {
// This "can't" happen.
System.out.println("Transformer Exception in numberLines");
return rtf;
}
}
/**
* <p>Setup the parameters associated with callouts</p>
*
* <p>This method queries the stylesheet for the variables
* associated with line numbering. It is called automatically before
* callouts are processed. The context is used to retrieve the values,
* this allows templates to redefine these variables.</p>
*
* <p>The following variables are queried. If the variables do not
* exist, builtin defaults will be used (but you may also get a bunch
* of messages from the Java interpreter).</p>
*
* <dl>
* <dt><code>callout.graphics</code></dt>
* <dd>Are we using callout graphics? A value of 0 or "" is false,
* any other value is true. If callout graphics are not used, the
* parameters related to graphis are not queried.</dd>
* <dt><code>callout.graphics.path</code></dt>
* <dd>Specifies the path to callout graphics.</dd>
* <dt><code>callout.graphics.extension</code></dt>
* <dd>Specifies the extension ot use for callout graphics.</dd>
* <dt><code>callout.graphics.number.limit</code></dt>
* <dd>Identifies the largest number that can be represented as a
* graphic. Larger callout numbers will be represented using text.</dd>
* <dt><code>callout.defaultcolumn</code></dt>
* <dd>Specifies the default column for callout bullets that do not
* specify a column.</dd>
* <dt><code>stylesheet.result.type</code></dt>
* <dd>Specifies the stylesheet result type. The value is either 'fo'
* (for XSL Formatting Objects) or it isn't. (builtin default: html).</dd>
* </dl>
*
* @param context The current stylesheet context
*
*/
private static void setupCallouts(Context context) {
NamePool namePool = context.getController().getNamePool();
boolean useGraphics = false;
boolean useUnicode = false;
int unicodeStart = 49;
int unicodeMax = 0;
String unicodeFont = "";
// Hardcoded defaults
defaultColumn = 60;
graphicsPath = null;
graphicsExt = null;
graphicsMax = 0;
foStylesheet = false;
calloutsSetup = true;
Value variable = null;
String varString = null;
// Get the stylesheet type
varString = getVariable(context, "stylesheet.result.type");
foStylesheet = (varString.equals("fo"));
// Get the default column
varString = getVariable(context, "callout.defaultcolumn");
try {
defaultColumn = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$callout.defaultcolumn is not a number: "
+ varString);
}
// Use graphics at all?
varString = getVariable(context, "callout.graphics");
useGraphics = !(varString.equals("0") || varString.equals(""));
// Use unicode at all?
varString = getVariable(context, "callout.unicode");
useUnicode = !(varString.equals("0") || varString.equals(""));
if (useGraphics) {
// Get the graphics path
varString = getVariable(context, "callout.graphics.path");
graphicsPath = varString;
// Get the graphics extension
varString = getVariable(context, "callout.graphics.extension");
graphicsExt = varString;
// Get the number limit
varString = getVariable(context, "callout.graphics.number.limit");
try {
graphicsMax = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$callout.graphics.number.limit is not a number: "
+ varString);
graphicsMax = 0;
}
fCallout = new FormatGraphicCallout(namePool,
graphicsPath,
graphicsExt,
graphicsMax,
foStylesheet);
} else if (useUnicode) {
// Get the starting character
varString = getVariable(context, "callout.unicode.start.character");
try {
unicodeStart = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$callout.unicode.start.character is not a number: "
+ varString);
unicodeStart = 48;
}
// Get the number limit
varString = getVariable(context, "callout.unicode.number.limit");
try {
unicodeMax = Integer.parseInt(varString);
} catch (NumberFormatException nfe) {
System.out.println("$callout.unicode.number.limit is not a number: "
+ varString);
unicodeStart = 0;
}
// Get the font
unicodeFont = getVariable(context, "callout.unicode.font");
if (unicodeFont == null) {
unicodeFont = "";
}
fCallout = new FormatUnicodeCallout(namePool,
unicodeFont,
unicodeStart,
unicodeMax,
foStylesheet);
} else {
fCallout = new FormatTextCallout(namePool, foStylesheet);
}
}
/**
* <p>Insert text callouts into a verbatim environment.</p>
*
* <p>This method examines the <tt>areaset</tt> and <tt>area</tt> elements
* in the supplied <tt>areaspec</tt> and decorates the supplied
* result tree fragment with appropriate callout markers.</p>
*
* <p>If a <tt>label</tt> attribute is supplied on an <tt>area</tt>,
* its content will be used for the label, otherwise the callout
* number will be used, surrounded by parenthesis. Callout numbers may
* also be represented as graphics. Callouts are
* numbered in document order. All of the <tt>area</tt>s in an
* <tt>areaset</tt> get the same number.</p>
*
* <p>Only the <tt>linecolumn</tt> and <tt>linerange</tt> units are
* supported. If no unit is specifed, <tt>linecolumn</tt> is assumed.
* If only a line is specified, the callout decoration appears in
* the defaultColumn. Lines will be padded with blanks to reach the
* necessary column, but callouts that are located beyond the last
* line of the verbatim environment will be ignored.</p>
*
* <p>Callouts are inserted before the character at the line/column
* where they are to occur.</p>
*
* <p>If graphical callouts are used, and the callout number is less
* than or equal to the $callout.graphics.number.limit, the following image
* will be generated for HTML:
*
* <pre>
* <img src="$callout.graphics.path/999$callout.graphics.ext"
* alt="conumber">
* </pre>
*
* If the $stylesheet.result.type is 'fo', the following image will
* be generated:
*
* <pre>
* <fo:external-graphic src="$callout.graphics.path/999$callout.graphics.ext"/>
* </pre>
*
* <p>If the callout number exceeds $callout.graphics.number.limit,
* the callout will be the callout number surrounded by
* parenthesis.</p>
*
* @param context The stylesheet context.
* @param areaspecNodeSet The source node set that contains the areaspec.
* @param rtf The result tree fragment of the verbatim environment.
*
* @return The modified result tree fragment.
*/
public static NodeSetValue insertCallouts (Context context,
NodeList areaspecNodeList,
NodeSetValue rtf_ns) {
FragmentValue rtf = (FragmentValue) rtf_ns;
setupCallouts(context);
try {
NamePool namePool = context.getController().getNamePool();
CalloutEmitter cEmitter = new CalloutEmitter(namePool,
defaultColumn,
foStylesheet,
fCallout);
cEmitter.setupCallouts(areaspecNodeList);
rtf.replay(cEmitter);
return cEmitter.getResultTreeFragment();
} catch (TransformerException e) {
// This "can't" happen.
System.out.println("Transformer Exception in insertCallouts");
return rtf;
}
}
}