/*
    * Copyright 2007 - 2008 JEuclid, http://jeuclid.sf.net
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /* $Id: BatikConverter.java,v 70597ba9d706 2008/02/18 19:42:05 maxberger $ */
  
  package net.sourceforge.jeuclid.converter;
  
  import java.awt.Dimension;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  
  import net.sourceforge.jeuclid.LayoutContext;
  import net.sourceforge.jeuclid.layout.JEuclidView;
  
  import org.apache.batik.svggen.SVGGeneratorContext;
  import org.apache.batik.svggen.SVGGraphics2D;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.w3c.dom.DOMImplementation;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  
  /**
   * supports conversion to SVG output through Batik.
   * 
   * @version $Revision: 70597ba9d706 $
   */
  public class BatikConverter implements ConverterPlugin {
  
      /**
       * Logger for this class
       */
      private static final Log LOGGER = LogFactory.getLog(BatikConverter.class);
  
      private final DOMImplementation domImplementation;
  
      BatikConverter(final DOMImplementation domImpl) {
          this.domImplementation = domImpl;
      }
  
      /** {@inheritDoc} */
      public Dimension convert(final Node doc, final LayoutContext context,
              final OutputStream outStream) throws IOException {
          final DocumentWithDimension svgDocDim = this.convert(doc, context);
          if (svgDocDim != null) {
              try {
                  final Transformer transformer = TransformerFactory
                          .newInstance().newTransformer();
                  final DOMSource source = new DOMSource(svgDocDim
                          .getDocument());
                  final StreamResult result = new StreamResult(outStream);
                  transformer.transform(source, result);
              } catch (final TransformerException e) {
                  BatikConverter.LOGGER.warn(e);
              }
              return svgDocDim.getDimension();
          }
          return null;
      }
  
      /** {@inheritDoc} */
      public DocumentWithDimension convert(final Node doc,
              final LayoutContext context) {
  
          Document document = null;
          final String svgNS = "http://www.w3.org/2000/svg";
          document = this.domImplementation.createDocument(svgNS, "svg", null);
          if (document != null) {
              final SVGGeneratorContext svgContext = SVGGeneratorContext
                      .createDefault(document);
              svgContext.setComment("Converted from MathML using JEuclid");
              final SVGGraphics2D svgGenerator = new SVGGraphics2D(svgContext,
                      true);
              final JEuclidView view = new JEuclidView(doc, context,
                      svgGenerator);
              final int ascent = (int) Math.ceil(view.getAscentHeight());
              final int descent = (int) Math.ceil(view.getDescentHeight());
              final int height = ascent + descent;
              final int width = (int) Math.ceil(view.getWidth());
              final Dimension size = new Dimension(width, height);
             svgGenerator.setSVGCanvasSize(size);
             view.draw(svgGenerator, 0, ascent);
             document.replaceChild(svgGenerator.getRoot(), document
                     .getFirstChild());
             return new DocumentWithDimension(document, new Dimension(width,
                     height), descent);
         }
         return null;
     }
 }