/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.xerces.xpointer;

import java.util.ArrayList;
import java.util.HashMap;

import org.apache.xerces.impl.Constants;
import org.apache.xerces.impl.XMLErrorReporter;
import org.apache.xerces.util.SymbolTable;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.util.XMLSymbols;
import org.apache.xerces.xinclude.XIncludeHandler;
import org.apache.xerces.xinclude.XIncludeNamespaceSupport;
import org.apache.xerces.xni.Augmentations;
import org.apache.xerces.xni.QName;
import org.apache.xerces.xni.XMLAttributes;
import org.apache.xerces.xni.XMLDocumentHandler;
import org.apache.xerces.xni.XMLString;
import org.apache.xerces.xni.XNIException;
import org.apache.xerces.xni.parser.XMLConfigurationException;
import org.apache.xerces.xni.parser.XMLErrorHandler;


This is a pipeline component which extends the XIncludeHandler to perform 
XPointer specific processing specified in the W3C XPointerFramework and 
element() Scheme Recommendations.


This component analyzes each event in the pipeline, looking for an element 
that matches a PointerPart in the parent XInclude element's xpointer attribute  
value.  If the match succeeds, all children are passed by this component.


See the XPointer Framework Recommendation for
more information on the XPointer Framework and ShortHand Pointers.
See the XPointer element() Scheme Recommendation for
more information on the XPointer element() Scheme. 
  
@xerces.internal
Version:
$Id: XPointerHandler.java 603808 2007-12-13 03:44:48Z mrglavas $/**
 * <p>
 * This is a pipeline component which extends the XIncludeHandler to perform 
 * XPointer specific processing specified in the W3C XPointerFramework and 
 * element() Scheme Recommendations.
 * </p>
 * 
 * <p>
 * This component analyzes each event in the pipeline, looking for an element 
 * that matches a PointerPart in the parent XInclude element's xpointer attribute  
 * value.  If the match succeeds, all children are passed by this component.
 * </p>
 * 
 * <p>
 * See the <a href="http://www.w3.org/TR/xptr-framework//">XPointer Framework Recommendation</a> for
 * more information on the XPointer Framework and ShortHand Pointers.
 * See the <a href="http://www.w3.org/TR/xptr-element/">XPointer element() Scheme Recommendation</a> for
 * more information on the XPointer element() Scheme. 
 * </p>  
 *
 * @xerces.internal

 * 
 * @version $Id: XPointerHandler.java 603808 2007-12-13 03:44:48Z mrglavas $
 */
public final class XPointerHandler extends XIncludeHandler implements
        XPointerProcessor {

    // Fields
    // An ArrayList of XPointerParts  
    protected ArrayList fXPointerParts = null;

    // The current XPointerPart  
    protected XPointerPart fXPointerPart = null;

    // Has the fXPointerPart resolved successfully
    protected boolean fFoundMatchingPtrPart = false;

    // The XPointer Error reporter
    protected XMLErrorReporter fXPointerErrorReporter;

    // The XPointer Error Handler
    protected XMLErrorHandler fErrorHandler;

    // XPointerFramework symbol table
    protected SymbolTable fSymbolTable = null;

    // Supported schemes
    private final String ELEMENT_SCHEME_NAME = "element";

   // Has the XPointer resolved the subresource
    protected boolean fIsXPointerResolved = false;
    
    // Fixup xml:base and xml:lang attributes
    protected boolean fFixupBase = false;
    protected boolean fFixupLang = false;
    
    // ************************************************************************
    // Constructors
    // ************************************************************************

    
 
/**
     *  
     */
    public XPointerHandler() {
        super();

        fXPointerParts = new ArrayList();
        fSymbolTable = new SymbolTable();
    }

    public XPointerHandler(SymbolTable symbolTable,
            XMLErrorHandler errorHandler, XMLErrorReporter errorReporter) {
        super();

        fXPointerParts = new ArrayList();
        fSymbolTable = symbolTable;
        fErrorHandler = errorHandler;
        fXPointerErrorReporter = errorReporter;
        //fErrorReporter = errorReporter; // The XInclude ErrorReporter
    }
    
    public void setDocumentHandler(XMLDocumentHandler handler) {
        fDocumentHandler = handler;
    }
    
    // ************************************************************************
    //  Implementation of the XPointerProcessor interface.
    // ************************************************************************

    
Parses the XPointer framework expression and delegates scheme specific parsing. 
  
See Also:
parseXPointer.parseXPointer(String)/** 
     * Parses the XPointer framework expression and delegates scheme specific parsing. 
     *   
     * @see org.apache.xerces.xpointer.XPointerProcessor#parseXPointer(java.lang.String)
     */
    public void parseXPointer(String xpointer) throws XNIException {

        // Initialize
        init();

        // tokens
        final Tokens tokens = new Tokens(fSymbolTable);

        // scanner
        Scanner scanner = new Scanner(fSymbolTable) {
            protected void addToken(Tokens tokens, int token)
                    throws XNIException {
                if (token == Tokens.XPTRTOKEN_OPEN_PAREN
                        || token == Tokens.XPTRTOKEN_CLOSE_PAREN
                        || token == Tokens.XPTRTOKEN_SCHEMENAME
                        || token == Tokens.XPTRTOKEN_SCHEMEDATA
                        || token == Tokens.XPTRTOKEN_SHORTHAND) {
                    super.addToken(tokens, token);
                    return;
                }
                reportError("InvalidXPointerToken", new Object[] { tokens
                        .getTokenString(token) });
            }
        };

        // scan the XPointer expression
        int length = xpointer.length();
        boolean success = scanner.scanExpr(fSymbolTable, tokens, xpointer, 0,
                length);

        if (!success)
            reportError("InvalidXPointerExpression", new Object[] { xpointer });

        while (tokens.hasMore()) {
            int token = tokens.nextToken();

            switch (token) {
            case Tokens.XPTRTOKEN_SHORTHAND: {

                // The shortHand name
                token = tokens.nextToken();
                String shortHandPointerName = tokens.getTokenString(token);

                if (shortHandPointerName == null) {
                    reportError("InvalidXPointerExpression",
                            new Object[] { xpointer });
                }

                XPointerPart shortHandPointer = new ShortHandPointer(
                        fSymbolTable);
                shortHandPointer.setSchemeName(shortHandPointerName);
                fXPointerParts.add(shortHandPointer);
                break;
            }
            case Tokens.XPTRTOKEN_SCHEMENAME: {

                // Retreive the local name and prefix to form the scheme name
                token = tokens.nextToken();
                String prefix = tokens.getTokenString(token);
                token = tokens.nextToken();
                String localName = tokens.getTokenString(token);

                String schemeName = prefix + localName;

                // The next character should be an open parenthesis
                int openParenCount = 0;
                int closeParenCount = 0;

                token = tokens.nextToken();
                String openParen = tokens.getTokenString(token);
                if (openParen != "XPTRTOKEN_OPEN_PAREN") {

                    // can not have more than one ShortHand Pointer
                    if (token == Tokens.XPTRTOKEN_SHORTHAND) {
                        reportError("MultipleShortHandPointers",
                                new Object[] { xpointer });
                    } else {
                        reportError("InvalidXPointerExpression",
                                new Object[] { xpointer });
                    }
                }
                openParenCount++;

                // followed by zero or more ( and  the schemeData
                String schemeData = null;
                while (tokens.hasMore()) {
                    token = tokens.nextToken();
                    schemeData = tokens.getTokenString(token);
                    if (schemeData != "XPTRTOKEN_OPEN_PAREN") {
                        break;
                    }
                    openParenCount++;
                }
                token = tokens.nextToken();
                schemeData = tokens.getTokenString(token);

                // followed by the same number of )
                token = tokens.nextToken();
                String closeParen = tokens.getTokenString(token);
                if (closeParen != "XPTRTOKEN_CLOSE_PAREN") {
                    reportError("SchemeDataNotFollowedByCloseParenthesis",
                            new Object[] { xpointer });
                }
                closeParenCount++;

                while (tokens.hasMore()) {
                    if (tokens.getTokenString(tokens.peekToken()) != "XPTRTOKEN_OPEN_PAREN") {
                        break;
                    }
                    closeParenCount++;
                }

                // check if the number of open parenthesis are equal to the number of close parenthesis
                if (openParenCount != closeParenCount) {
                    reportError("UnbalancedParenthesisInXPointerExpression",
                            new Object[] { xpointer,
                                    new Integer(openParenCount),
                                    new Integer(closeParenCount) });
                }

                // Perform scheme specific parsing of the pointer part
                if (schemeName.equals(ELEMENT_SCHEME_NAME)) {
                    XPointerPart elementSchemePointer = new ElementSchemePointer(
                            fSymbolTable, fErrorReporter);
                    elementSchemePointer.setSchemeName(schemeName);
                    elementSchemePointer.setSchemeData(schemeData);

                    // If an exception occurs while parsing the element() scheme expression
                    // ignore it and move on to the next pointer part
                    try {
                        elementSchemePointer.parseXPointer(schemeData);
                        fXPointerParts.add(elementSchemePointer);
                    } catch (XNIException e) {
                        // Re-throw the XPointer element() scheme syntax error.
                    	throw new XNIException (e);
                    }

                } else {
                    // ????
                    reportWarning("SchemeUnsupported",
                            new Object[] { schemeName });
                }

                break;
            }
            default:
                reportError("InvalidXPointerExpression",
                        new Object[] { xpointer });
            }
        }

    }

    
 
See Also:
org.apache.xerces.xpointer.XPointerProcessor#resolveXPointer(org.apache.xerces.xni.QName, org.apache.xerces.xni.XMLAttributes, org.apache.xerces.xni.Augmentations, int event)/**
     *  
     * @see org.apache.xerces.xpointer.XPointerProcessor#resolveXPointer(org.apache.xerces.xni.QName, org.apache.xerces.xni.XMLAttributes, org.apache.xerces.xni.Augmentations, int event)
     */
    public boolean resolveXPointer(QName element, XMLAttributes attributes,
            Augmentations augs, int event) throws XNIException {
    	boolean resolved = false;
    	
        // The result of the first pointer part whose evaluation identifies 
        // one or more subresources is reported by the XPointer processor as the 
        // result of the pointer as a whole, and evaluation stops.
        // In our implementation, typically the first xpointer scheme that 
        // matches an element is the document is considered.
        // If the pointer part resolved then use it, else search for the fragment
        // using next pointer part from lef-right.
        if (!fFoundMatchingPtrPart) {

            // for each element, attempt to resolve it against each pointer part 
            // in the XPointer expression until a matching element is found.
            for (int i = 0; i < fXPointerParts.size(); i++) {

                fXPointerPart = (XPointerPart) fXPointerParts.get(i);

                if (fXPointerPart.resolveXPointer(element, attributes, augs,
                        event)) {
                    fFoundMatchingPtrPart = true;
                    resolved = true;
                }
            }
        } else {
            if (fXPointerPart.resolveXPointer(element, attributes, augs, event)) {
            	resolved = true;
            }
        }

        if (!fIsXPointerResolved) {
            fIsXPointerResolved = resolved;
        }

        return resolved;
    }

    
Returns true if the Node fragment is resolved.
See Also:
isFragmentResolved.isFragmentResolved()/**
     * Returns true if the Node fragment is resolved.
     * 
     * @see org.apache.xerces.xpointer.XPointerProcessor#isFragmentResolved()
     */
    public boolean isFragmentResolved() throws XNIException {
        boolean resolved = (fXPointerPart != null) ? fXPointerPart.isFragmentResolved()
                : false;
        
        if (!fIsXPointerResolved) {
            fIsXPointerResolved = resolved;
        }
        
        return resolved;
    }

    
Returns true if the XPointer expression resolves to a non-element child
of the current resource fragment.       
See Also:
isChildFragmentResolved.isChildFragmentResolved()/**
     * Returns true if the XPointer expression resolves to a non-element child
     * of the current resource fragment.       
     * 
     * @see org.apache.xerces.xpointer.XPointerPart#isChildFragmentResolved()
     *   
     */
    public boolean isChildFragmentResolved() throws XNIException {
    	boolean resolved = (fXPointerPart != null) ? fXPointerPart
				.isChildFragmentResolved() : false;
		return resolved;
    }

    
Returns true if the XPointer successfully found a sub-resource .
See Also:
isFragmentResolved.isFragmentResolved()/**
     * Returns true if the XPointer successfully found a sub-resource .
     * 
     * @see org.apache.xerces.xpointer.XPointerProcessor#isFragmentResolved()
     */
    public boolean isXPointerResolved() throws XNIException {
        return fIsXPointerResolved;
    }
    
    
Returns the pointer part used to resolve the document fragment.
Returns:
String - The pointer part used to resolve the document fragment./**
     * Returns the pointer part used to resolve the document fragment.
     * 
     * @return String - The pointer part used to resolve the document fragment.
     */
    public XPointerPart getXPointerPart() {
        return fXPointerPart;
    }

    
Reports XPointer Errors
/**
     * Reports XPointer Errors
     * 
     */
    private void reportError(String key, Object[] arguments)
            throws XNIException {
        /* 
        fXPointerErrorReporter.reportError(
                XPointerMessageFormatter.XPOINTER_DOMAIN, key, arguments,
                XMLErrorReporter.SEVERITY_ERROR);
        */        
    	throw new XNIException((fErrorReporter
				.getMessageFormatter(XPointerMessageFormatter.XPOINTER_DOMAIN))
				.formatMessage(fErrorReporter.getLocale(), key, arguments));
    }

    
Reports XPointer Warnings
/**
     * Reports XPointer Warnings
     * 
     */
    private void reportWarning(String key, Object[] arguments)
            throws XNIException {
        fXPointerErrorReporter.reportError(
                XPointerMessageFormatter.XPOINTER_DOMAIN, key, arguments,
                XMLErrorReporter.SEVERITY_WARNING);
    }

    
Initializes error handling objects
/**
     * Initializes error handling objects
     * 
     */
    protected void initErrorReporter() {
        if (fXPointerErrorReporter == null) {
            fXPointerErrorReporter = new XMLErrorReporter();
        }
        if (fErrorHandler == null) {
            fErrorHandler = new XPointerErrorHandler();
        }
        /*
         fXPointerErrorReporter.setProperty(Constants.XERCES_PROPERTY_PREFIX
         + Constants.ERROR_HANDLER_PROPERTY, fErrorHandler);
         */
        fXPointerErrorReporter.putMessageFormatter(
                XPointerMessageFormatter.XPOINTER_DOMAIN,
                new XPointerMessageFormatter());
    }

    
Initializes the XPointer Processor;
/**
     * Initializes the XPointer Processor;
     */
    protected void init() {
        fXPointerParts.clear();
        fXPointerPart = null;
        fFoundMatchingPtrPart = false;
        fIsXPointerResolved = false;
        //fFixupBase = false;
        //fFixupLang = false;

        initErrorReporter();
    }

    
Returns an ArrayList of XPointerPart objects
Returns:
An ArrayList of XPointerPart objects./**
     * Returns an ArrayList of XPointerPart objects
     * 
     * @return An ArrayList of XPointerPart objects.
     */
    public ArrayList getPointerParts() {
        return fXPointerParts;
    }

    
List of XPointer Framework tokens.
@xerces.internal
/**
     * List of XPointer Framework tokens.
     * 
     * @xerces.internal

     * 
     */
    private final class Tokens {

        
XPointer Framework tokens
[1] Pointer     ::= Shorthand | SchemeBased 
[2] Shorthand   ::= NCName 
[3] SchemeBased ::= PointerPart (S? PointerPart)* 
[4] PointerPart ::= SchemeName '(' SchemeData ')' 
[5] SchemeName  ::= QName 
[6] SchemeData  ::= EscapedData* 
[7] EscapedData ::= NormalChar | '^(' | '^)' | '^^' | '(' SchemeData ')' 
[8] NormalChar  ::= UnicodeChar - [()^] 
[9] UnicodeChar ::= [#x0-#x10FFFF]
 
/**
         * XPointer Framework tokens
         * [1] Pointer     ::= Shorthand | SchemeBased 
         * [2] Shorthand   ::= NCName 
         * [3] SchemeBased ::= PointerPart (S? PointerPart)* 
         * [4] PointerPart ::= SchemeName '(' SchemeData ')' 
         * [5] SchemeName  ::= QName 
         * [6] SchemeData  ::= EscapedData* 
         * [7] EscapedData ::= NormalChar | '^(' | '^)' | '^^' | '(' SchemeData ')' 
         * [8] NormalChar  ::= UnicodeChar - [()^] 
         * [9] UnicodeChar ::= [#x0-#x10FFFF]
         *  
         */
        private static final int XPTRTOKEN_OPEN_PAREN = 0,
                XPTRTOKEN_CLOSE_PAREN = 1, XPTRTOKEN_SHORTHAND = 2,
                XPTRTOKEN_SCHEMENAME = 3, XPTRTOKEN_SCHEMEDATA = 4;

        // Token names
        private final String[] fgTokenNames = { "XPTRTOKEN_OPEN_PAREN",
                "XPTRTOKEN_CLOSE_PAREN", "XPTRTOKEN_SHORTHAND",
                "XPTRTOKEN_SCHEMENAME", "XPTRTOKEN_SCHEMEDATA" };

        // Token count
        private static final int INITIAL_TOKEN_COUNT = 1 << 8;

        private int[] fTokens = new int[INITIAL_TOKEN_COUNT];

        private int fTokenCount = 0;

        // Current token position
        private int fCurrentTokenIndex;

        private SymbolTable fSymbolTable;

        private HashMap fTokenNames = new HashMap();

        
Constructor 
Params:
symbolTable – SymbolTable/**
         * Constructor 
         * 
         * @param symbolTable SymbolTable
         */
        private Tokens(SymbolTable symbolTable) {
            fSymbolTable = symbolTable;

            fTokenNames.put(new Integer(XPTRTOKEN_OPEN_PAREN),
                    "XPTRTOKEN_OPEN_PAREN");
            fTokenNames.put(new Integer(XPTRTOKEN_CLOSE_PAREN),
                    "XPTRTOKEN_CLOSE_PAREN");
            fTokenNames.put(new Integer(XPTRTOKEN_SHORTHAND),
                    "XPTRTOKEN_SHORTHAND");
            fTokenNames.put(new Integer(XPTRTOKEN_SCHEMENAME),
                    "XPTRTOKEN_SCHEMENAME");
            fTokenNames.put(new Integer(XPTRTOKEN_SCHEMEDATA),
                    "XPTRTOKEN_SCHEMEDATA");
        }

        
Returns the token String 
Params:
token – The index of the token
Returns:
String The token string/**
         * Returns the token String 
         * @param token The index of the token
         * @return String The token string
         */
        private String getTokenString(int token) {
            return (String) fTokenNames.get(new Integer(token));
        }

        
Add the specified string as a token
 
Params:
token – The token string/**
         * Add the specified string as a token
         *  
         * @param token The token string
         */
        private void addToken(String tokenStr) {
            Integer tokenInt = (Integer) fTokenNames.get(tokenStr);
            if (tokenInt == null) {
                tokenInt = new Integer(fTokenNames.size());
                fTokenNames.put(tokenInt, tokenStr);
            }
            addToken(tokenInt.intValue());
        }

        
Add the specified int token
 
Params:
token – The int specifying the token/**
         * Add the specified int token
         *  
         * @param token The int specifying the token
         */
        private void addToken(int token) {
            try {
                fTokens[fTokenCount] = token;
            } catch (ArrayIndexOutOfBoundsException ex) {
                int[] oldList = fTokens;
                fTokens = new int[fTokenCount << 1];
                System.arraycopy(oldList, 0, fTokens, 0, fTokenCount);
                fTokens[fTokenCount] = token;
            }
            fTokenCount++;
        }

        
Resets the current position to the head of the token list.
/**
         * Resets the current position to the head of the token list.
         */
        private void rewind() {
            fCurrentTokenIndex = 0;
        }

        
Returns true if the getNextToken() method returns a valid token. /**
         * Returns true if the {@link #getNextToken()} method
         * returns a valid token.
         */
        private boolean hasMore() {
            return fCurrentTokenIndex < fTokenCount;
        }

        
Obtains the token at the current position, then advance
the current position by one.
throws If there's no such next token, this method throws
new XNIException("XPointerProcessingError");.
/**
         * Obtains the token at the current position, then advance
         * the current position by one.
         * 
         * throws If there's no such next token, this method throws
         * <tt>new XNIException("XPointerProcessingError");</tt>.
         */
        private int nextToken() throws XNIException {
            if (fCurrentTokenIndex == fTokenCount) {
                reportError("XPointerProcessingError", null);
            }
            return fTokens[fCurrentTokenIndex++];
        }

        
Obtains the token at the current position, without advancing
the current position.
If there's no such next token, this method throws
new XNIException("XPointerProcessingError");.
/**
         * Obtains the token at the current position, without advancing
         * the current position.
         * 
         * If there's no such next token, this method throws
         * <tt>new XNIException("XPointerProcessingError");</tt>.
         */
        private int peekToken() throws XNIException {
            if (fCurrentTokenIndex == fTokenCount) {
                reportError("XPointerProcessingError", null);
            }
            return fTokens[fCurrentTokenIndex];
        }

        
Obtains the token at the current position as a String.
If there's no current token or if the current token
is not a string token, this method throws 
If there's no such next token, this method throws
new XNIException("XPointerProcessingError");.
/**
         * Obtains the token at the current position as a String.
         * 
         * If there's no current token or if the current token
         * is not a string token, this method throws 
         * If there's no such next token, this method throws
         * <tt>new XNIException("XPointerProcessingError");</tt>.
         */
        private String nextTokenAsString() throws XNIException {
            String tokenStrint = getTokenString(nextToken());
            if (tokenStrint == null) {
                reportError("XPointerProcessingError", null);
            }
            return tokenStrint;
        }
    }

    
The XPointer expression scanner.  Scans the XPointer framework expression.
@xerces.internal
/**
     * 
     * The XPointer expression scanner.  Scans the XPointer framework expression.
     * 
     * @xerces.internal

     * 
     */
    private class Scanner {

        
7-bit ASCII subset
 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
 0,  0,  0,  0,  0,  0,  0,  0,  0, HT, LF,  0,  0, CR,  0,  0,  // 0
 0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  // 1
SP,  !,  ",  #,  $,  %,  &,  ',  (,  ),  *,  +,  ,,  -,  .,  /,  // 2
 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  :,  ;,  <,  =,  >,  ?,  // 3
 @,  A,  B,  C,  D,  E,  F,  G,  H,  I,  J,  K,  L,  M,  N,  O,  // 4
 P,  Q,  R,  S,  T,  U,  V,  W,  X,  Y,  Z,  [,  \,  ],  ^,  _,  // 5
 `,  a,  b,  c,  d,  e,  f,  g,  h,  i,  j,  k,  l,  m,  n,  o,  // 6
 p,  q,  r,  s,  t,  u,  v,  w,  x,  y,  z,  {,  |,  },  ~, DEL  // 7
/**
         * 7-bit ASCII subset
         *
         *  0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
         *  0,  0,  0,  0,  0,  0,  0,  0,  0, HT, LF,  0,  0, CR,  0,  0,  // 0
         *  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  // 1
         * SP,  !,  ",  #,  $,  %,  &,  ',  (,  ),  *,  +,  ,,  -,  .,  /,  // 2
         *  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  :,  ;,  <,  =,  >,  ?,  // 3
         *  @,  A,  B,  C,  D,  E,  F,  G,  H,  I,  J,  K,  L,  M,  N,  O,  // 4
         *  P,  Q,  R,  S,  T,  U,  V,  W,  X,  Y,  Z,  [,  \,  ],  ^,  _,  // 5
         *  `,  a,  b,  c,  d,  e,  f,  g,  h,  i,  j,  k,  l,  m,  n,  o,  // 6
         *  p,  q,  r,  s,  t,  u,  v,  w,  x,  y,  z,  {,  |,  },  ~, DEL  // 7
         */
        private static final byte CHARTYPE_INVALID = 0, // invalid XML character
                CHARTYPE_OTHER = 1, // not special - one of "#%&;?\`{}~" or DEL
                CHARTYPE_WHITESPACE = 2, // one of "\t\n\r " (0x09, 0x0A, 0x0D, 0x20)
                CHARTYPE_CARRET = 3, // ^
                CHARTYPE_OPEN_PAREN = 4, // '(' (0x28)
                CHARTYPE_CLOSE_PAREN = 5, // ')' (0x29)
                CHARTYPE_MINUS = 6, // '-' (0x2D)
                CHARTYPE_PERIOD = 7, // '.' (0x2E)
                CHARTYPE_SLASH = 8, // '/' (0x2F)
                CHARTYPE_DIGIT = 9, // '0'-'9' (0x30 to 0x39)
                CHARTYPE_COLON = 10, // ':' (0x3A)
                CHARTYPE_EQUAL = 11, // '=' (0x3D)
                CHARTYPE_LETTER = 12, // 'A'-'Z' or 'a'-'z' (0x41 to 0x5A and 0x61 to 0x7A)
                CHARTYPE_UNDERSCORE = 13, // '_' (0x5F)
                CHARTYPE_NONASCII = 14; // Non-ASCII Unicode codepoint (>= 0x80)

        private final byte[] fASCIICharMap = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2,
                0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                2, 1, 1, 1, 1, 1, 1, 1, 4, 5, 1, 1, 1, 6, 7, 8, 9, 9, 9, 9, 9,
                9, 9, 9, 9, 9, 10, 1, 1, 11, 1, 1, 1, 12, 12, 12, 12, 12, 12,
                12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
                12, 12, 12, 12, 1, 1, 1, 3, 13, 1, 12, 12, 12, 12, 12, 12, 12,
                12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
                12, 12, 12, 1, 1, 1, 1, 1 };

        //
        // Data
        //
        
Symbol table. /** Symbol table. */
        private SymbolTable fSymbolTable;

        
Constructs an XPointer Framework expression scanner. 
Params:
symbolTable – SymbolTable/** 
         * Constructs an XPointer Framework expression scanner. 
         *
         * @param symbolTable SymbolTable  
         */
        private Scanner(SymbolTable symbolTable) {
            // save pool and tokens
            fSymbolTable = symbolTable;

        } // <init>(SymbolTable)

        
Scans the XPointer Expression
/**
         * Scans the XPointer Expression
         * 
         */
        private boolean scanExpr(SymbolTable symbolTable, Tokens tokens,
                String data, int currentOffset, int endOffset)
                throws XNIException {

            int ch;
            int openParen = 0;
            int closeParen = 0;
            int nameOffset, dataOffset;
            boolean isQName = false;
            String name = null;
            String prefix = null;
            String schemeData = null;
            StringBuffer schemeDataBuff = new StringBuffer();

            while (true) {

                if (currentOffset == endOffset) {
                    break;
                }
                ch = data.charAt(currentOffset);

                // 
                while (ch == ' ' || ch == 0x0A || ch == 0x09 || ch == 0x0D) {
                    if (++currentOffset == endOffset) {
                        break;
                    }
                    ch = data.charAt(currentOffset);
                }
                if (currentOffset == endOffset) {
                    break;
                }

                // 
                // [1]    Pointer      ::=    Shorthand | SchemeBased  
                // [2]    Shorthand    ::=    NCName  
                // [3]    SchemeBased  ::=    PointerPart (S? PointerPart)* 
                // [4]    PointerPart  ::=    SchemeName '(' SchemeData ')' 
                // [5]    SchemeName   ::=    QName  
                // [6]    SchemeData   ::=    EscapedData*  
                // [7]    EscapedData  ::=    NormalChar | '^(' | '^)' | '^^' | '(' SchemeData ')'  
                // [8]    NormalChar   ::=    UnicodeChar - [()^]  
                // [9]    UnicodeChar  ::=    [#x0-#x10FFFF]
                // [?]    QName        ::=    (NCName ':')? NCName
                // [?]    NCName       ::=    (Letter | '_') (NCNameChar)*
                // [?]    NCNameChar   ::=    Letter | Digit | '.' | '-' | '_'  (ascii subset of 'NCNameChar')
                // [?]    Letter       ::=    [A-Za-z]                              (ascii subset of 'Letter')
                // [?]    Digit        ::=    [0-9]                                  (ascii subset of 'Digit')
                // 
                byte chartype = (ch >= 0x80) ? CHARTYPE_NONASCII
                        : fASCIICharMap[ch];

                switch (chartype) {

                case CHARTYPE_OPEN_PAREN: // '('
                    addToken(tokens, Tokens.XPTRTOKEN_OPEN_PAREN);
                    openParen++;
                    ++currentOffset;
                    break;

                case CHARTYPE_CLOSE_PAREN: // ')'
                    addToken(tokens, Tokens.XPTRTOKEN_CLOSE_PAREN);
                    closeParen++;
                    ++currentOffset;
                    break;

                case CHARTYPE_CARRET:
                case CHARTYPE_COLON:
                case CHARTYPE_DIGIT:
                case CHARTYPE_EQUAL:
                case CHARTYPE_LETTER:
                case CHARTYPE_MINUS:
                case CHARTYPE_NONASCII:
                case CHARTYPE_OTHER:
                case CHARTYPE_PERIOD:
                case CHARTYPE_SLASH:
                case CHARTYPE_UNDERSCORE:
                case CHARTYPE_WHITESPACE:
                    // Scanning SchemeName | Shorthand                   
                    if (openParen == 0) {
                        nameOffset = currentOffset;
                        currentOffset = scanNCName(data, endOffset,
                                currentOffset);

                        if (currentOffset == nameOffset) {
                            reportError("InvalidShortHandPointer",
                                    new Object[] { data });
                            return false;
                        }

                        if (currentOffset < endOffset) {
                            ch = data.charAt(currentOffset);
                        } else {
                            ch = -1;
                        }

                        name = symbolTable.addSymbol(data.substring(nameOffset,
                                currentOffset));
                        prefix = XMLSymbols.EMPTY_STRING;

                        // The name is a QName => a SchemeName
                        if (ch == ':') {
                            if (++currentOffset == endOffset) {
                                return false;
                            }

                            ch = data.charAt(currentOffset);
                            prefix = name;
                            nameOffset = currentOffset;
                            currentOffset = scanNCName(data, endOffset,
                                    currentOffset);

                            if (currentOffset == nameOffset) {
                                return false;
                            }

                            if (currentOffset < endOffset) {
                                ch = data.charAt(currentOffset);
                            } else {
                                ch = -1;
                            }

                            isQName = true;
                            name = symbolTable.addSymbol(data.substring(
                                    nameOffset, currentOffset));
                        }

                        // REVISIT:
                        if (currentOffset != endOffset) {
                            addToken(tokens, Tokens.XPTRTOKEN_SCHEMENAME);
                            tokens.addToken(prefix);
                            tokens.addToken(name);
                            isQName = false;
                        } else if (currentOffset == endOffset) {
                            // NCName => Shorthand
                            addToken(tokens, Tokens.XPTRTOKEN_SHORTHAND);
                            tokens.addToken(name);
                            isQName = false;
                        }

                        // reset open/close paren for the next pointer part
                        closeParen = 0;

                        break;

                    } else if (openParen > 0 && closeParen == 0 && name != null) {
                        // Scanning SchemeData
                        dataOffset = currentOffset;
                        currentOffset = scanData(data, schemeDataBuff,
                                endOffset, currentOffset);

                        if (currentOffset == dataOffset) {
                            reportError("InvalidSchemeDataInXPointer",
                                    new Object[] { data });
                            return false;
                        }

                        if (currentOffset < endOffset) {
                            ch = data.charAt(currentOffset);
                        } else {
                            ch = -1;
                        }

                        schemeData = symbolTable.addSymbol(schemeDataBuff
                                .toString());
                        addToken(tokens, Tokens.XPTRTOKEN_SCHEMEDATA);
                        tokens.addToken(schemeData);

                        // reset open/close paren for the next pointer part
                        openParen = 0;
                        schemeDataBuff.delete(0, schemeDataBuff.length());

                    } else {
                        // ex. schemeName()
                        // Should we throw an exception with a more suitable message instead??
                        return false;
                    }
                }
            } // end while
            return true;
        }

        
Scans a NCName.  
From Namespaces in XML 
[5] NCName ::= (Letter | '_') (NCNameChar)*
[6] NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender
Params:
data – A String containing the XPointer expression
endOffset – The int XPointer expression length
currentOffset – An int representing the current position of the XPointer expression pointer/** 
         * Scans a NCName.  
         * From Namespaces in XML 
         * [5] NCName ::= (Letter | '_') (NCNameChar)*
         * [6] NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender
         * 
         * @param data A String containing the XPointer expression
         * @param endOffset The int XPointer expression length  
         * @param currentOffset An int representing the current position of the XPointer expression pointer
         */
        private int scanNCName(String data, int endOffset, int currentOffset) {
            int ch = data.charAt(currentOffset);
            if (ch >= 0x80) {
                if (!XMLChar.isNameStart(ch)) {
                    return currentOffset;
                }
            } else {
                byte chartype = fASCIICharMap[ch];
                if (chartype != CHARTYPE_LETTER
                        && chartype != CHARTYPE_UNDERSCORE) {
                    return currentOffset;
                }
            }

            //while (currentOffset++ < endOffset) {
            while (++currentOffset < endOffset) {
                ch = data.charAt(currentOffset);
                if (ch >= 0x80) {
                    if (!XMLChar.isName(ch)) {
                        break;
                    }
                } else {
                    byte chartype = fASCIICharMap[ch];
                    if (chartype != CHARTYPE_LETTER
                            && chartype != CHARTYPE_DIGIT
                            && chartype != CHARTYPE_PERIOD
                            && chartype != CHARTYPE_MINUS
                            && chartype != CHARTYPE_UNDERSCORE) {
                        break;
                    }
                }
            }
            return currentOffset;
        }

        
Scans the SchemeData.
[6]    SchemeData   ::=    EscapedData*  
[7]    EscapedData  ::=    NormalChar | '^(' | '^)' | '^^' | '(' SchemeData ')'  
[8]    NormalChar   ::=    UnicodeChar - [()^]  
[9]    UnicodeChar  ::=    [#x0-#x10FFFF]
/**
         * Scans the SchemeData.
         * [6]    SchemeData   ::=    EscapedData*  
         * [7]    EscapedData  ::=    NormalChar | '^(' | '^)' | '^^' | '(' SchemeData ')'  
         * [8]    NormalChar   ::=    UnicodeChar - [()^]  
         * [9]    UnicodeChar  ::=    [#x0-#x10FFFF]
         * 
         */
        private int scanData(String data, StringBuffer schemeData,
                int endOffset, int currentOffset) {
            while (true) {

                if (currentOffset == endOffset) {
                    break;
                }

                int ch = data.charAt(currentOffset);
                byte chartype = (ch >= 0x80) ? CHARTYPE_NONASCII
                        : fASCIICharMap[ch];

                if (chartype == CHARTYPE_OPEN_PAREN) {
                    schemeData.append(ch);
                    //schemeData.append(Tokens.XPTRTOKEN_OPEN_PAREN);
                    currentOffset = scanData(data, schemeData, endOffset,
                            ++currentOffset);
                    if (currentOffset == endOffset) {
                        return currentOffset;
                    }

                    ch = data.charAt(currentOffset);
                    chartype = (ch >= 0x80) ? CHARTYPE_NONASCII
                            : fASCIICharMap[ch];

                    if (chartype != CHARTYPE_CLOSE_PAREN) {
                        return endOffset;
                    }
                    schemeData.append((char) ch);
                    ++currentOffset;//

                } else if (chartype == CHARTYPE_CLOSE_PAREN) {
                    return currentOffset;
                    
                } else  if (chartype == CHARTYPE_CARRET) {
                    ch = data.charAt(++currentOffset);
                    chartype = (ch >= 0x80) ? CHARTYPE_NONASCII
                            : fASCIICharMap[ch];

                    if (chartype != CHARTYPE_CARRET
                            && chartype != CHARTYPE_OPEN_PAREN
                            && chartype != CHARTYPE_CLOSE_PAREN) {
                        break;
                    }
                    schemeData.append((char) ch);
                    ++currentOffset;

                } else {
                    schemeData.append((char) ch);
                    ++currentOffset;//
                }
            }

            return currentOffset;
        }

        //
        // Protected methods
        //

        
This method adds the specified token to the token list. By
default, this method allows all tokens. However, subclasses
of the XPathExprScanner can override this method in order
to disallow certain tokens from being used in the scanned
XPath expression. This is a convenient way of allowing only
a subset of XPath.
/**
         * This method adds the specified token to the token list. By
         * default, this method allows all tokens. However, subclasses
         * of the XPathExprScanner can override this method in order
         * to disallow certain tokens from being used in the scanned
         * XPath expression. This is a convenient way of allowing only
         * a subset of XPath.
         */
        protected void addToken(Tokens tokens, int token) throws XNIException {
            tokens.addToken(token);
        } // addToken(int)

    } // class Scanner

    // ************************************************************************
    //  Overridden XMLDocumentHandler methods
    // ************************************************************************
    
If the comment is a child of a matched element, then pass else return.
Params:
text –   The text in the comment.
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by application to signal an error./**
     * If the comment is a child of a matched element, then pass else return.
     * 
     * @param text   The text in the comment.
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by application to signal an error.
     */
    public void comment(XMLString text, Augmentations augs) throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.comment(text, augs);
    }

    
A processing instruction. Processing instructions consist of a
target name and, optionally, text data. The data is only meaningful
to the application.

Typically, a processing instruction's data will contain a series
of pseudo-attributes. These pseudo-attributes follow the form of
element attributes but are not parsed or presented
to the application as anything other than text. The application is
responsible for parsing the data.
Params:
target – The target.
data –   The data or null if none specified.
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * A processing instruction. Processing instructions consist of a
     * target name and, optionally, text data. The data is only meaningful
     * to the application.
     * <p>
     * Typically, a processing instruction's data will contain a series
     * of pseudo-attributes. These pseudo-attributes follow the form of
     * element attributes but are <strong>not</strong> parsed or presented
     * to the application as anything other than text. The application is
     * responsible for parsing the data.
     * 
     * @param target The target.
     * @param data   The data or null if none specified.
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void processingInstruction(String target, XMLString data,
            Augmentations augs) throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.processingInstruction(target, data, augs);
    }

    
The start of an element.
Params:
element –    The name of the element.
attributes – The element attributes.
augs –       Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * The start of an element.
     * 
     * @param element    The name of the element.
     * @param attributes The element attributes.
     * @param augs       Additional information that may include infoset augmentations
     *                   
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void startElement(QName element, XMLAttributes attributes,
            Augmentations augs) throws XNIException {
        if (!resolveXPointer(element, attributes, augs,
                XPointerPart.EVENT_ELEMENT_START)) {

            // xml:base and xml:lang processing
        	if (fFixupBase) {
                processXMLBaseAttributes(attributes);
        	}
            if (fFixupLang) {
                processXMLLangAttributes(attributes);
            }

            // set the context invalid if the element till an element from the result infoset is included
            fNamespaceContext.setContextInvalid(); 

            return;
        }
        super.startElement(element, attributes, augs);
    }

    
An empty element.
Params:
element –    The name of the element.
attributes – The element attributes.
augs –       Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * An empty element.
     * 
     * @param element    The name of the element.
     * @param attributes The element attributes.
     * @param augs       Additional information that may include infoset augmentations
     *                   
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void emptyElement(QName element, XMLAttributes attributes,
            Augmentations augs) throws XNIException {
        if (!resolveXPointer(element, attributes, augs,
                XPointerPart.EVENT_ELEMENT_EMPTY)) {
            // xml:base and xml:lang processing
        	if (fFixupBase) {
                processXMLBaseAttributes(attributes);
        	}    
            if (fFixupLang) {
                processXMLLangAttributes(attributes);
            }
            // no need to restore restoreBaseURI() for xml:base and xml:lang processing
            
            // set the context invalid if the element till an element from the result infoset is included
            fNamespaceContext.setContextInvalid(); 
            return;
        }
        super.emptyElement(element, attributes, augs);
    }

    
Character content.
Params:
text –   The content.
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * Character content.
     * 
     * @param text   The content.
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void characters(XMLString text, Augmentations augs)
            throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.characters(text, augs);
    }

    
Ignorable whitespace. For this method to be called, the document
source must have some way of determining that the text containing
only whitespace characters should be considered ignorable. For
example, the validator can determine if a length of whitespace
characters in the document are ignorable based on the element
content model.
Params:
text –   The ignorable whitespace.
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * Ignorable whitespace. For this method to be called, the document
     * source must have some way of determining that the text containing
     * only whitespace characters should be considered ignorable. For
     * example, the validator can determine if a length of whitespace
     * characters in the document are ignorable based on the element
     * content model.
     * 
     * @param text   The ignorable whitespace.
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void ignorableWhitespace(XMLString text, Augmentations augs)
            throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.ignorableWhitespace(text, augs);
    }

    
The end of an element.
Params:
element – The name of the element.
augs –    Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * The end of an element.
     * 
     * @param element The name of the element.
     * @param augs    Additional information that may include infoset augmentations
     *                
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void endElement(QName element, Augmentations augs)
            throws XNIException {
        if (!resolveXPointer(element, null, augs,
                XPointerPart.EVENT_ELEMENT_END)) {

            // no need to restore restoreBaseURI() for xml:base and xml:lang processing
            return;
        }
        super.endElement(element, augs);
    }

    
The start of a CDATA section.
Params:
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * The start of a CDATA section.
     * 
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void startCDATA(Augmentations augs) throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.startCDATA(augs);
    }

    
The end of a CDATA section.
Params:
augs –   Additional information that may include infoset augmentations
Throws:
XNIException – 
                  Thrown by handler to signal an error./**
     * The end of a CDATA section.
     * 
     * @param augs   Additional information that may include infoset augmentations
     *               
     * @exception XNIException
     *                   Thrown by handler to signal an error.
     */
    public void endCDATA(Augmentations augs) throws XNIException {
        if (!isChildFragmentResolved()) {
            return;
        }
        super.endCDATA(augs);
    }

    // ************************************************************************
    // Overridden XMLComponent methods
    // ************************************************************************
    

Sets the value of a property. This method is called by the component
manager any time after reset when a property changes value.

Note: Components should silently ignore properties
that do not affect the operation of the component.
Params:
propertyId – The property identifier.
value –      The value of the property.
Throws:
XMLConfigurationException – Thrown for configuration error.
                                 In general, components should
                                 only throw this exception if
                                 it is really
                                 a critical error./**
     * <p>
     * Sets the value of a property. This method is called by the component
     * manager any time after reset when a property changes value.
     * </p>
     * <strong>Note:</strong> Components should silently ignore properties
     * that do not affect the operation of the component.
     *
     * @param propertyId The property identifier.
     * @param value      The value of the property.
     *
     * @throws XMLConfigurationException Thrown for configuration error.
     *                                  In general, components should
     *                                  only throw this exception if
     *                                  it is <strong>really</strong>
     *                                  a critical error.
     */
    public void setProperty(String propertyId, Object value)
            throws XMLConfigurationException {

        // Error reporter
        if (propertyId == Constants.XERCES_PROPERTY_PREFIX
                + Constants.ERROR_REPORTER_PROPERTY) {
            if (value != null) {
                fXPointerErrorReporter = (XMLErrorReporter) value;
            } else {
                fXPointerErrorReporter = null;
            }
        }

        // Error handler
        if (propertyId == Constants.XERCES_PROPERTY_PREFIX
                + Constants.ERROR_HANDLER_PROPERTY) {
            if (value != null) {
                fErrorHandler = (XMLErrorHandler) value;
            } else {
                fErrorHandler = null;
            }
        }

        // xml:lang
        if (propertyId == Constants.XERCES_FEATURE_PREFIX
                + Constants.XINCLUDE_FIXUP_LANGUAGE_FEATURE) {
            if (value != null) {
            	fFixupLang = ((Boolean)value).booleanValue();
            } else {
            	fFixupLang = false;
            }
        }
        
        // xml:base
        if (propertyId == Constants.XERCES_FEATURE_PREFIX
                + Constants.XINCLUDE_FIXUP_BASE_URIS_FEATURE) {
            if (value != null) {
            	fFixupBase = ((Boolean)value).booleanValue();
            } else {
            	fFixupBase = false;
            }
        }
        
        // 
        if (propertyId == Constants.XERCES_PROPERTY_PREFIX
                + Constants.NAMESPACE_CONTEXT_PROPERTY) {
            fNamespaceContext = (XIncludeNamespaceSupport) value;
        }

        super.setProperty(propertyId, value);
    }

}