RootLayerFilter.java

/*******************************************************************************
 * Copyright 2010 Simon Mieth
 * 
 * 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.
 ******************************************************************************/

package org.kabeja.svg;

import org.kabeja.xml.AbstractSAXFilter;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;


/**
 * This filter removes the SVG group "draft" which holds the complete drawing.
 *
 * @author simon
 *
 */
public class RootLayerFilter extends AbstractSAXFilter {
    private boolean inDraftSection = false;
    private int groupDepth = 0;
    private String transformValue = "";
    private String strokeWidth = "";
    


    public void endElement(String uri, String localName, String qName)
        throws SAXException {
        if (this.inDraftSection) {
            if (uri.equals(SVGConstants.SVG_NAMESPACE) &&
                    localName.equals(SVGConstants.SVG_GROUP)) {
                if (this.groupDepth == 1) {
                    // we filter out the main group
                    this.inDraftSection = false;

                    return;
                }

                groupDepth--;
            }
        }

        super.endElement(uri, localName, qName);
    }

    public void startElement(String uri, String localName, String qName,
        Attributes atts) throws SAXException {
  
        if (uri.equals(SVGConstants.SVG_NAMESPACE) &&
                localName.equals(SVGConstants.SVG_GROUP)) {
            String id = atts.getValue(SVGConstants.XML_ID);

            if (((id != null) && id.equals("draft")) || this.inDraftSection) {
      
            	switch (groupDepth) {
                case 0:
                    // the root group
                    this.transformValue = atts.getValue(SVGConstants.SVG_ATTRIBUTE_TRANSFORM);
                    this.inDraftSection = true;
                    this.strokeWidth = atts.getValue(SVGConstants.SVG_ATTRIBUTE_STROKE_WITDH);

                    break;

                case 1:

                    AttributesImpl attributes = new AttributesImpl(atts);

                    if (attributes.getIndex(
                                SVGConstants.SVG_ATTRIBUTE_TRANSFORM) != -1) {
                        attributes.setAttribute(attributes.getIndex(
                                SVGConstants.SVG_ATTRIBUTE_TRANSFORM), "",
                            SVGConstants.SVG_ATTRIBUTE_TRANSFORM,
                            SVGConstants.SVG_ATTRIBUTE_TRANSFORM,
                            SVGUtils.DEFAUL_ATTRIBUTE_TYPE,
                            this.transformValue + " " +
                            attributes.getValue(
                                SVGConstants.SVG_ATTRIBUTE_TRANSFORM));
                    } else {
                        attributes.addAttribute("",
                            SVGConstants.SVG_ATTRIBUTE_TRANSFORM,
                            SVGConstants.SVG_ATTRIBUTE_TRANSFORM,
                            SVGUtils.DEFAUL_ATTRIBUTE_TYPE, this.transformValue);
                    }

                    if (attributes.getIndex(
                                SVGConstants.SVG_ATTRIBUTE_STROKE_WITDH) == -1) {
                        attributes.addAttribute("",
                            SVGConstants.SVG_ATTRIBUTE_STROKE_WITDH,
                            SVGConstants.SVG_ATTRIBUTE_STROKE_WITDH,
                            SVGUtils.DEFAUL_ATTRIBUTE_TYPE, this.strokeWidth);
                    }

                    super.startElement(uri, localName, qName, attributes);

                    break;

                default:
                    super.startElement(uri, localName, qName, atts);

                    break;
                }

                this.groupDepth++;

                return;
            }
        }

        super.startElement(uri, localName, qName, atts);
    }
}