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: }
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