org.pmedv.core.components.ExtendedHTMLEditorKit.java Source code

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Here is the source code for org.pmedv.core.components.ExtendedHTMLEditorKit.java

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/**
    
   BlackBoard BreadBoard Designer
   Written and maintained by Matthias Pueski 
       
   Copyright (c) 2010-2011 Matthias Pueski
       
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.
       
   This program 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 for more details.
       
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
    
*/
/*
GNU Lesser General Public License
    
ExtendedHTMLEditorKit
Copyright (C) 2001-2002  Frits Jalvingh & Howard Kistler
changes to ExtendedHTMLEditorKit
Copyright (C) 2003-2004  Karsten Pawlik
    
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
    
This library 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
Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package org.pmedv.core.components;

import java.net.URL;

import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.StyleConstants;
import javax.swing.text.View;
import javax.swing.text.ViewFactory;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLEditorKit;
import javax.swing.text.html.StyleSheet;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
  * Description: This class extends HTMLEditorKit so that it can provide other renderer classes
  * instead of the defaults. Most important is the part which renders relative
  * image paths.
  *
  * @author <a href="mailto:jal@grimor.com">Frits Jalvingh</a>
  * @version 1.0
  */

public class ExtendedHTMLEditorKit extends HTMLEditorKit {

    private static final Log log = LogFactory.getLog(ExtendedHTMLEditorKit.class);

    /** 
     * Constructor
     */
    public ExtendedHTMLEditorKit() {
    }

    /** 
     * Method for returning a ViewFactory which handles the image rendering.
     * @return returns a new ViewFactory Object.
     */
    public ViewFactory getViewFactory() {
        return new HTMLFactoryExtended();
    }

    /**
     * creates a default document
     * @return returns a Document
     */
    public Document createDefaultDocument() {
        return createDefaultDocument(null);
    }

    /**
     * creates a default document and sets the base url to the given value.
     * @param baseUrl creates the default document and sets the base url
     * of the html-document to the given value. if base url is null,
     * no base url will be set.
     * @return returns a Document
     */
    public Document createDefaultDocument(URL baseUrl) {
        StyleSheet styles = getStyleSheet();
        StyleSheet ss = new StyleSheet();
        ss.addStyleSheet(styles);
        ExtendedHTMLDocument doc = new ExtendedHTMLDocument(ss);
        if (baseUrl != null)
            doc.setBase(baseUrl);
        doc.setParser(getParser());
        doc.setAsynchronousLoadPriority(4);
        doc.setTokenThreshold(100);
        return doc;
    }

    /** 
     * Class that replaces the default ViewFactory and supports
     * the proper rendering of both URL-based and local images.
     */
    public static class HTMLFactoryExtended extends HTMLFactory implements ViewFactory {
        /** 
         * Constructor
         */
        public HTMLFactoryExtended() {
        }

        /** 
         * Method to handle IMG tags and
         * invoke the image loader.
         * @param elem an element to create
         * @return a View
         */
        public View create(Element elem) {
            Object obj = elem.getAttributes().getAttribute(StyleConstants.NameAttribute);
            if (obj instanceof HTML.Tag) {
                HTML.Tag tagType = (HTML.Tag) obj;
                if (tagType == HTML.Tag.IMG) {
                    try {
                        return new RelativeImageView(elem);
                    } catch (Exception e) {
                        log.warn("Error while trying to create new RelativeImageView for element");
                    }
                }
            }
            return super.create(elem);
        }
    }
}