TeXTokenMarker.java :  » Game » aetheria » org » jedit » syntax » Java Open Source

package org.jedit.syntax;

/*
 * TeXTokenMarker.java - TeX/LaTeX/AMS-TeX token marker
 * Copyright (C) 1998 Slava Pestov
 *
 * You may use and modify this package for any purpose. Redistribution is
 * permitted, in both source and binary form, provided that this notice
 * remains intact in all source distributions of this package.
 */

import javax.swing.text.Segment;

/**
 * TeX token marker.
 *
 * @author Slava Pestov
 * @version $Id: TeXTokenMarker.java,v 1.16 1999/12/13 03:40:30 sp Exp $
 */
public class TeXTokenMarker extends TokenMarker
{
  // public members
  public static final byte BDFORMULA = Token.INTERNAL_FIRST;
  public static final byte EDFORMULA = (byte)(Token.INTERNAL_FIRST + 1);
  
  public byte markTokensImpl(byte token, Segment line, int lineIndex)
  {
    char[] array = line.array;
    int offset = line.offset;
    int lastOffset = offset;
    int length = line.count + offset;
    boolean backslash = false;
loop:    for(int i = offset; i < length; i++)
    {
      int i1 = (i+1);

      char c = array[i];
      // if a backslash is followed immediately
      // by a non-alpha character, the command at
      // the non-alpha char. If we have a backslash,
      // some text, and then a non-alpha char,
      // the command ends before the non-alpha char.
      if(Character.isLetter(c))
      {
        backslash = false;
      }
      else
      {
        if(backslash)
        {
          // \<non alpha>
          // we skip over this character,
          // hence the `continue'
          backslash = false;
          if(token == Token.KEYWORD2 || token == EDFORMULA)
            token = Token.KEYWORD2;
          addToken(i1 - lastOffset,token);
          lastOffset = i1;
          if(token == Token.KEYWORD1)
            token = Token.NULL;
          continue;
        }
        else
        {
          //\blah<non alpha>
          // we leave the character in
          // the stream, and it's not
          // part of the command token
          if(token == BDFORMULA || token == EDFORMULA)
            token = Token.KEYWORD2;
          addToken(i - lastOffset,token);
          if(token == Token.KEYWORD1)
            token = Token.NULL;
          lastOffset = i;
        }
      }
      switch(c)
      {
      case '%':
        if(backslash)
        {
          backslash = false;
          break;
        }
        addToken(i - lastOffset,token);
        addToken(length - i,Token.COMMENT1);
        lastOffset = length;
        break loop;
      case '\\':
        backslash = true;
        if(token == Token.NULL)
        {
          token = Token.KEYWORD1;
          addToken(i - lastOffset,Token.NULL);
          lastOffset = i;
        }
        break;
      case '$':
        backslash = false;
        if(token == Token.NULL) // singe $
        {
          token = Token.KEYWORD2;
          addToken(i - lastOffset,Token.NULL);
          lastOffset = i;
        }
        else if(token == Token.KEYWORD1) // \...$
        {
          token = Token.KEYWORD2;
          addToken(i - lastOffset,Token.KEYWORD1);
          lastOffset = i;
        }
        else if(token == Token.KEYWORD2) // $$aaa
        {
          if(i - lastOffset == 1 && array[i-1] == '$')
          {
            token = BDFORMULA;
            break;
          }
          token = Token.NULL;
          addToken(i1 - lastOffset,Token.KEYWORD2);
          lastOffset = i1;
        }
        else if(token == BDFORMULA) // $$aaa$
        {
          token = EDFORMULA;
        }
        else if(token == EDFORMULA) // $$aaa$$
        {
          token = Token.NULL;
          addToken(i1 - lastOffset,Token.KEYWORD2);
          lastOffset = i1;
        }
        break;
      }
    }
    if(lastOffset != length)
      addToken(length - lastOffset,token == BDFORMULA
        || token == EDFORMULA ? Token.KEYWORD2 :
        token);
    return (token != Token.KEYWORD1 ? token : Token.NULL);
  }
}