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	/*
	* Copyright (c) 1998, 2013, 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 javax.swing.text.html.parser;

	import javax.swing.text.SimpleAttributeSet;
	import javax.swing.text.html.HTMLEditorKit;
	import javax.swing.text.html.HTML;
	import javax.swing.text.ChangedCharSetException;

	import java.util.*;
	import java.io.*;
	import java.net.*;

	/**
	* A Parser for HTML Documents (actually, you can specify a DTD, but
	* you should really only use this class with the html dtd in swing).
	* Reads an InputStream of HTML and
	* invokes the appropriate methods in the ParserCallback class. This
	* is the default parser used by HTMLEditorKit to parse HTML url's.
	* <p>This will message the callback for all valid tags, as well as
	* tags that are implied but not explicitly specified. For example, the
	* html string (<p>blah) only has a p tag defined. The callback
	* will see the following methods:
	* <ol><li><i>handleStartTag(html, ...)</i></li>
	* <li><i>handleStartTag(head, ...)</i></li>
	* <li><i>handleEndTag(head)</i></li>
	* <li><i>handleStartTag(body, ...)</i></li>
	* <li><i>handleStartTag(p, ...)</i></li>
	* <li><i>handleText(...)</i></li>
	* <li><i>handleEndTag(p)</i></li>
	* <li><i>handleEndTag(body)</i></li>
	* <li><i>handleEndTag(html)</i></li>
	* </ol>
	* The items in <i>italic</i> are implied, that is, although they were not
	* explicitly specified, to be correct html they should have been present
	* (head isn't necessary, but it is still generated). For tags that
	* are implied, the AttributeSet argument will have a value of
	* <code>Boolean.TRUE</code> for the key
	* <code>HTMLEditorKit.ParserCallback.IMPLIED</code>.
	* <p>HTML.Attributes defines a type safe enumeration of html attributes.
	* If an attribute key of a tag is defined in HTML.Attribute, the
	* HTML.Attribute will be used as the key, otherwise a String will be used.
	* For example <p foo=bar class=neat> has two attributes. foo is
	* not defined in HTML.Attribute, where as class is, therefore the
	* AttributeSet will have two values in it, HTML.Attribute.CLASS with
	* a String value of 'neat' and the String key 'foo' with a String value of
	* 'bar'.
	* <p>The position argument will indicate the start of the tag, comment
	* or text. Similar to arrays, the first character in the stream has a
	* position of 0. For tags that are
	* implied the position will indicate
	* the location of the next encountered tag. In the first example,
	* the implied start body and html tags will have the same position as the
	* p tag, and the implied end p, html and body tags will all have the same
	* position.
	* <p>As html skips whitespace the position for text will be the position
	* of the first valid character, eg in the string '\n\n\nblah'
	* the text 'blah' will have a position of 3, the newlines are skipped.
	* <p>
	* For attributes that do not have a value, eg in the html
	* string <code><foo blah></code> the attribute <code>blah</code>
	* does not have a value, there are two possible values that will be
	* placed in the AttributeSet's value:
	* <ul>
	* <li>If the DTD does not contain an definition for the element, or the
	* definition does not have an explicit value then the value in the
	* AttributeSet will be <code>HTML.NULL_ATTRIBUTE_VALUE</code>.
	* <li>If the DTD contains an explicit value, as in:
	* <code><!ATTLIST OPTION selected (selected) #IMPLIED></code>
	* this value from the dtd (in this case selected) will be used.
	* </ul>
	* <p>
	* Once the stream has been parsed, the callback is notified of the most
	* likely end of line string. The end of line string will be one of
	* \n, \r or \r\n, which ever is encountered the most in parsing the
	* stream.
	*
	* @author Sunita Mani
	*/
	public class DocumentParser extends javax.swing.text.html.parser.Parser {

	private int inbody;
	private int intitle;
	private int inhead;
	private int instyle;
	private int inscript;
	private boolean seentitle;
	private HTMLEditorKit.ParserCallback callback = null;
	private boolean ignoreCharSet = false;
	private static final boolean debugFlag = false;

	public DocumentParser(DTD dtd) {
	super(dtd);
	}

	public void parse(Reader in, HTMLEditorKit.ParserCallback callback, boolean ignoreCharSet) throws IOException {
	this.ignoreCharSet = ignoreCharSet;
	this.callback = callback;
	parse(in);
	// end of line
	callback.handleEndOfLineString(getEndOfLineString());
	}

	/**
	* Handle Start Tag.
	*/
	protected void handleStartTag(TagElement tag) {

	Element elem = tag.getElement();
	if (elem == dtd.body) {
	inbody++;
	} else if (elem == dtd.html) {
	} else if (elem == dtd.head) {
	inhead++;
	} else if (elem == dtd.title) {
	intitle++;
	} else if (elem == dtd.style) {
	instyle++;
	} else if (elem == dtd.script) {
	inscript++;
	}
	if (debugFlag) {
	if (tag.fictional()) {
	debug("Start Tag: " + tag.getHTMLTag() + " pos: " + getCurrentPos());
	} else {
	debug("Start Tag: " + tag.getHTMLTag() + " attributes: " +
	getAttributes() + " pos: " + getCurrentPos());
	}
	}
	if (tag.fictional()) {
	SimpleAttributeSet attrs = new SimpleAttributeSet();
	attrs.addAttribute(HTMLEditorKit.ParserCallback.IMPLIED,
	Boolean.TRUE);
	callback.handleStartTag(tag.getHTMLTag(), attrs,
	getBlockStartPosition());
	} else {
	callback.handleStartTag(tag.getHTMLTag(), getAttributes(),
	getBlockStartPosition());
	flushAttributes();
	}
	}


	protected void handleComment(char text[]) {
	if (debugFlag) {
	debug("comment: ->" + new String(text) + "<-"
	+ " pos: " + getCurrentPos());
	}
	callback.handleComment(text, getBlockStartPosition());
	}

	/**
	* Handle Empty Tag.
	*/
	protected void handleEmptyTag(TagElement tag) throws ChangedCharSetException {

	Element elem = tag.getElement();
	if (elem == dtd.meta && !ignoreCharSet) {
	SimpleAttributeSet atts = getAttributes();
	if (atts != null) {
	String content = (String)atts.getAttribute(HTML.Attribute.CONTENT);
	if (content != null) {
	if ("content-type".equalsIgnoreCase((String)atts.getAttribute(HTML.Attribute.HTTPEQUIV))) {
	if (!content.equalsIgnoreCase("text/html") &&
	!content.equalsIgnoreCase("text/plain")) {
	throw new ChangedCharSetException(content, false);
	}
	} else if ("charset" .equalsIgnoreCase((String)atts.getAttribute(HTML.Attribute.HTTPEQUIV))) {
	throw new ChangedCharSetException(content, true);
	}
	}
	}
	}
	if (inbody != 0 \|\| elem == dtd.meta \|\| elem == dtd.base \|\| elem == dtd.isindex \|\| elem == dtd.style \|\| elem == dtd.link) {
	if (debugFlag) {
	if (tag.fictional()) {
	debug("Empty Tag: " + tag.getHTMLTag() + " pos: " + getCurrentPos());
	} else {
	debug("Empty Tag: " + tag.getHTMLTag() + " attributes: "
	+ getAttributes() + " pos: " + getCurrentPos());
	}
	}
	if (tag.fictional()) {
	SimpleAttributeSet attrs = new SimpleAttributeSet();
	attrs.addAttribute(HTMLEditorKit.ParserCallback.IMPLIED,
	Boolean.TRUE);
	callback.handleSimpleTag(tag.getHTMLTag(), attrs,
	getBlockStartPosition());
	} else {
	callback.handleSimpleTag(tag.getHTMLTag(), getAttributes(),
	getBlockStartPosition());
	flushAttributes();
	}
	}
	}

	/**
	* Handle End Tag.
	*/
	protected void handleEndTag(TagElement tag) {
	Element elem = tag.getElement();
	if (elem == dtd.body) {
	inbody--;
	} else if (elem == dtd.title) {
	intitle--;
	seentitle = true;
	} else if (elem == dtd.head) {
	inhead--;
	} else if (elem == dtd.style) {
	instyle--;
	} else if (elem == dtd.script) {
	inscript--;
	}
	if (debugFlag) {
	debug("End Tag: " + tag.getHTMLTag() + " pos: " + getCurrentPos());
	}
	callback.handleEndTag(tag.getHTMLTag(), getBlockStartPosition());

	}

	/**
	* Handle Text.
	*/
	protected void handleText(char data[]) {
	if (data != null) {
	if (inscript != 0) {
	callback.handleComment(data, getBlockStartPosition());
	return;
	}
	if (inbody != 0 \|\| ((instyle != 0) \|\|
	((intitle != 0) && !seentitle))) {
	if (debugFlag) {
	debug("text: ->" + new String(data) + "<-" + " pos: " + getCurrentPos());
	}
	callback.handleText(data, getBlockStartPosition());
	}
	}
	}

	/*
	* Error handling.
	*/
	protected void handleError(int ln, String errorMsg) {
	if (debugFlag) {
	debug("Error: ->" + errorMsg + "<-" + " pos: " + getCurrentPos());
	}
	/* PENDING: need to improve the error string. */
	callback.handleError(errorMsg, getCurrentPos());
	}


	/*
	* debug messages
	*/
	private void debug(String msg) {
	System.out.println(msg);
	}
	}

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