/* * @(#)DocumentParser.java	1.28 03/12/19 * * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */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 (&lt;p&gt;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>handleStartTag(p, ...)</i></li> *     <li>handleText(...)</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 &lt;p foo=bar class=neat&gt; 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. Similiar 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>&lt;foo blah&gt;</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>&lt;!ATTLIST OPTION selected (selected) #IMPLIED&gt;</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. * * @version 	1.28 12/19/03 * @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);    }}