/* * HtmlVisitor.java * Copyright (C) 1999 Quiotix Corporation.   * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2, as  * published by the Free Software Foundation.   * * 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 (http://www.gnu.org/copyleft/gpl.txt) * for more details. */package com.quiotix.html.parser;import java.util.*;/**  * Abstract class implementing Visitor pattern for HtmlDocument objects.   * * @author Brian Goetz, Quiotix */public abstract class HtmlVisitor {  public void visit(HtmlDocument.Tag t)         { }  public void visit(HtmlDocument.EndTag t)      { }  public void visit(HtmlDocument.Comment c)     { }  public void visit(HtmlDocument.Text t)        { }  public void visit(HtmlDocument.Newline n)     { }  public void visit(HtmlDocument.Annotation a)  { }  public void visit(HtmlDocument.TagBlock bl) {    bl.startTag.accept(this);    visit(bl.body);    bl.endTag.accept(this);  }  public void visit(HtmlDocument.ElementSequence s) {    for (Enumeration e = s.elements();          e.hasMoreElements(); )      ((HtmlDocument.HtmlElement)e.nextElement()).accept(this);  }  public void visit(HtmlDocument d) {    start();    visit(d.elements);    finish();  }  public void start()  { }  public void finish() { }}