| /* |
| * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.tools.internal.xjc.util; |
| |
| import org.xml.sax.helpers.XMLFilterImpl; |
| import org.xml.sax.helpers.DefaultHandler; |
| import org.xml.sax.XMLFilter; |
| import org.xml.sax.ContentHandler; |
| import org.xml.sax.SAXException; |
| import org.xml.sax.Attributes; |
| |
| /** |
| * {@link XMLFilter} that can cut sub-trees. |
| * |
| * @author Kohsuke Kawaguchi |
| */ |
| public abstract class SubtreeCutter extends XMLFilterImpl { |
| /** |
| * When we are pruning a sub tree, this field holds the depth of |
| * elements that are being cut. Used to resume event forwarding. |
| * |
| * As long as this value is 0, we will pass through data. |
| */ |
| private int cutDepth=0; |
| |
| |
| /** |
| * This object will receive SAX events while a sub tree is being |
| * pruned. |
| */ |
| private static final ContentHandler stub = new DefaultHandler(); |
| |
| /** |
| * This field remembers the user-specified ContentHandler. |
| * So that we can restore it once the sub tree is completely pruned. |
| */ |
| private ContentHandler next; |
| |
| |
| public void startDocument() throws SAXException { |
| cutDepth=0; |
| super.startDocument(); |
| } |
| |
| public boolean isCutting() { |
| return cutDepth>0; |
| } |
| |
| /** |
| * Starts cutting a sub-tree. Should be called from within the |
| * {@link #startElement(String, String, String, Attributes)} implementation |
| * before the execution is passed to {@link SubtreeCutter#startElement(String, String, String, Attributes)} . |
| * The current element will be cut. |
| */ |
| public void startCutting() { |
| super.setContentHandler(stub); |
| cutDepth=1; |
| } |
| |
| public void setContentHandler(ContentHandler handler) { |
| next = handler; |
| // changes take effect immediately unless the sub-tree is being pruned |
| if(getContentHandler()!=stub) |
| super.setContentHandler(handler); |
| } |
| |
| public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException { |
| if(cutDepth>0) |
| cutDepth++; |
| super.startElement(uri, localName, qName, atts); |
| } |
| |
| public void endElement(String namespaceURI, String localName, String qName) throws SAXException { |
| super.endElement(namespaceURI, localName, qName); |
| |
| if( cutDepth!=0 ) { |
| cutDepth--; |
| if( cutDepth == 1 ) { |
| // pruning completed. restore the user handler |
| super.setContentHandler(next); |
| cutDepth=0; |
| } |
| } |
| } |
| } |