001 /* =========================================================== 002 * JFreeChart : a free chart library for the Java(tm) platform 003 * =========================================================== 004 * 005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. 006 * 007 * Project Info: http://www.jfree.org/jfreechart/index.html 008 * 009 * This library is free software; you can redistribute it and/or modify it 010 * under the terms of the GNU Lesser General Public License as published by 011 * the Free Software Foundation; either version 2.1 of the License, or 012 * (at your option) any later version. 013 * 014 * This library is distributed in the hope that it will be useful, but 015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 017 * License for more details. 018 * 019 * You should have received a copy of the GNU Lesser General Public 020 * License along with this library; if not, write to the Free Software 021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 022 * USA. 023 * 024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 025 * in the United States and other countries.] 026 * 027 * ---------------- 028 * RootHandler.java 029 * ---------------- 030 * (C) Copyright 2003-2005, by Object Refinery Limited and Contributors. 031 * 032 * Original Author: David Gilbert (for Object Refinery Limited); 033 * Contributor(s): -; 034 * 035 * $Id: RootHandler.java,v 1.3.2.1 2005/10/25 21:36:10 mungady Exp $ 036 * 037 * Changes 038 * ------- 039 * 23-Jan-2003 : Version 1 (DG); 040 * 041 */ 042 043 package org.jfree.data.xml; 044 045 import java.util.Stack; 046 047 import org.xml.sax.SAXException; 048 import org.xml.sax.helpers.DefaultHandler; 049 050 /** 051 * A SAX handler that delegates work to sub-handlers. 052 */ 053 public class RootHandler extends DefaultHandler implements DatasetTags { 054 055 /** The sub-handlers. */ 056 private Stack subHandlers; 057 058 /** 059 * Creates a new handler. 060 */ 061 public RootHandler() { 062 this.subHandlers = new Stack(); 063 } 064 065 /** 066 * Returns the stack of sub handlers. 067 * 068 * @return The sub-handler stack. 069 */ 070 public Stack getSubHandlers() { 071 return this.subHandlers; 072 } 073 074 /** 075 * Receives some (or all) of the text in the current element. 076 * 077 * @param ch character buffer. 078 * @param start the start index. 079 * @param length the length of the valid character data. 080 * 081 * @throws SAXException for errors. 082 */ 083 public void characters(char[] ch, int start, int length) 084 throws SAXException { 085 DefaultHandler handler = getCurrentHandler(); 086 if (handler != this) { 087 handler.characters(ch, start, length); 088 } 089 } 090 091 /** 092 * Returns the handler at the top of the stack. 093 * 094 * @return The handler. 095 */ 096 public DefaultHandler getCurrentHandler() { 097 DefaultHandler result = this; 098 if (this.subHandlers != null) { 099 if (this.subHandlers.size() > 0) { 100 Object top = this.subHandlers.peek(); 101 if (top != null) { 102 result = (DefaultHandler) top; 103 } 104 } 105 } 106 return result; 107 } 108 109 /** 110 * Pushes a sub-handler onto the stack. 111 * 112 * @param subhandler the sub-handler. 113 */ 114 public void pushSubHandler(DefaultHandler subhandler) { 115 this.subHandlers.push(subhandler); 116 } 117 118 /** 119 * Pops a sub-handler from the stack. 120 * 121 * @return The sub-handler. 122 */ 123 public DefaultHandler popSubHandler() { 124 return (DefaultHandler) this.subHandlers.pop(); 125 } 126 127 }