DefaultTokenHandler.java :  » Swing-Library » jEdit-4.3.1 » org » gjt » sp » jedit » syntax » Java Open Source

/*
 * DefaultTokenHandler.java - Builds a linked list of Token objects
 * :tabSize=8:indentSize=8:noTabs=false:
 * :folding=explicit:collapseFolds=1:
 *
 * Copyright (C) 2002 Slava Pestov
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.gjt.sp.jedit.syntax;

import javax.swing.text.Segment;

/**
 * Builds a linked list of tokens without any additional processing.
 *
 * @author Slava Pestov
 * @version $Id: DefaultTokenHandler.java 12504 2008-04-22 23:12:43Z ezust $
 * @since jEdit 4.1pre1
 */
public class DefaultTokenHandler implements TokenHandler
{
  //{{{ reset() method
  /**
   * Clears the list of tokens.
   */
  public void init()
  {
    lastToken = firstToken = null;
  } //}}}

  //{{{ getTokens() method
  /**
   * Returns the first syntax token.
   * @since jEdit 4.1pre1
   */
  public Token getTokens()
  {
    return firstToken;
  } //}}}

  //{{{ handleToken() method
  /**
   * Called by the token marker when a syntax token has been parsed.
   * @param seg The segment containing the text
   * @param id The token type (one of the constants in the
   * {@link Token} class).
   * @param offset The start offset of the token
   * @param length The number of characters in the token
   * @param context The line context
   * @since jEdit 4.2pre3
   */
  public void handleToken(Segment seg, byte id, int offset, int length,
    TokenMarker.LineContext context)
  {
    Token token = createToken(id,offset,length,context);
    if(token != null)
      addToken(token,context);
  } //}}}

  //{{{ getLineContext() method
  /**
   * The token handler can compare this object with the object
   * previously given for this line to see if the token type at the end
   * of the line has changed (meaning subsequent lines might need to be
   * retokenized).
   * @since jEdit 4.2pre6
   */
  public TokenMarker.LineContext getLineContext()
  {
    return lineContext;
  } //}}}

  //{{{ setLineContext() method
  /**
   * The token handler can compare this object with the object
   * previously given for this line to see if the token type at the end
   * of the line has changed (meaning subsequent lines might need to be
   * retokenized).
   * @since jEdit 4.2pre6
   */
  public void setLineContext(TokenMarker.LineContext lineContext)
  {
    this.lineContext = lineContext;
  } //}}}

  //{{{ Protected members
  protected Token firstToken, lastToken;
  protected TokenMarker.LineContext lineContext;

  //{{{ getParserRuleSet() method
  protected ParserRuleSet getParserRuleSet(TokenMarker.LineContext context)
  {
    while(context != null)
    {
      if(!context.rules.isBuiltIn())
        return context.rules;

      context = context.parent;
    }

    return null;
  } //}}}

  //{{{ createToken() method
  protected Token createToken(byte id, int offset, int length,
    TokenMarker.LineContext context)
  {
    return new Token(id,offset,length,getParserRuleSet(context));
  } //}}}

  //{{{ addToken() method
  protected void addToken(Token token, TokenMarker.LineContext context)
  {
    if(firstToken == null)
    {
      firstToken = lastToken = token;
    }
    else
    {
      lastToken.next = token;
      lastToken = lastToken.next;
    }
  } //}}}

  //}}}
}