/**********************************************
    * Copyright (C) 2010 Lukas Laag
    * This file is part of svgreal.
    * 
    * svgreal 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 3 of the License, or
    * (at your option) any later version.
    * 
   * svgreal 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 svgreal.  If not, see http://www.gnu.org/licenses/
   **********************************************/
  package org.vectomatic.svg.edit.client.engine;
  
  /**
   * Class to split SVG attribute values into a stream of
   * tokens. Each token is either a piece of text to be
   * quoted verbatim by the SVG id normalizer, or an idref
   * to be replaced by a normalized id ref.
   * @author laaglu
   */
  public class IdRefTokenizer {
  	protected static final String START = "url(#";
  	protected static final String END = ")";
  	static class IdRefToken {
  		public static final int IDREF = 1;
  		public static final int DATA = 2;
  		int kind;
  		String value;
  		public int getKind() {
  			return kind;
  		}
  		public String getValue() {
  			return value;
  		}
  	}
  	protected IdRefToken token = new IdRefToken();
  	protected String str;
  	protected int index1;
  	protected int index2;
  
  	public void tokenize(String str) {
  		this.str = str;
  		index1 = 0;
  		index2 = 0;
  		token.kind = IdRefToken.IDREF;
  		token.value = null;
  	}
  	public IdRefToken nextToken() {
  		if (index1 != str.length()) {
  			if (token.kind == IdRefToken.IDREF) {
  				token.kind = IdRefToken.DATA;
  				index2 = str.indexOf(START, index1);
  				if (index2 != -1) {
  					token.value = str.substring(index1, index2 + START.length());
  					index1 = index2 + START.length();
  				} else {
  					token.value = str.substring(index1);
  					index1 = str.length();
  				}
  			} else {
  				index2 = str.indexOf(END, index1);
  				if (index2 != -1) {
  					token.value = str.substring(index1, index2);
  					index1 = index2;
  					token.kind = IdRefToken.IDREF;
  				} else {
  					token.value = str.substring(index1);
  					index1 = str.length();
  				}
  			}
  			return token;
  		}
  		return null;
  	}
  }