batik-test-svg/src/main/java/org/apache/batik/test/svg/SVGRenderingAccuracyTest.java

/*

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You 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.apache.batik.test.svg;

import java.awt.Color;
import java.io.FileOutputStream;
import java.io.StringWriter;
import java.io.PrintWriter;
import java.net.URL;

import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;

import org.apache.batik.transcoder.image.ImageTranscoder;
import org.apache.batik.transcoder.image.PNGTranscoder;

import org.apache.batik.test.DefaultTestReport;
import org.apache.batik.test.TestReport;

import org.w3c.dom.Document;


/**
 * Checks for regressions in rendering a specific SVG document.
 * The <code>Test</code> will rasterize and SVG document and 
 * compare it to a reference image. The test passes if the 
 * rasterized SVG and the reference image match exactly (i.e.,
 * all pixel values are the same).
 *
 * @author <a href="mailto:vhardy@apache.lorg">Vincent Hardy</a>
 * @version $Id$
 */
public class SVGRenderingAccuracyTest extends AbstractRenderingAccuracyTest {
    /**
     * Error when transcoding the SVG document generates an error
     * {0} = URI of the transcoded SVG file
     * {1} = Exception class
     * {2} = Exception message
     * {3} = Stack trace.
     */
    public static final String ERROR_CANNOT_TRANSCODE_SVG           
        = "SVGRenderingAccuracyTest.error.cannot.transcode.svg";

    /**
     * Validating parser class name
     */
    public static final String VALIDATING_PARSER
        = configuration.getString("validating.parser");

    /**
     * Controls whether or not the SVG file should be
     * validated. By default, no validation is used.
     */
    protected boolean validate = false;

    /**
     * The userLanguage for which the document should be tested.
     */
    protected String userLanguage;

    /**
     * Constructor.
     * @param svgURL the URL String for the SVG document being tested.
     * @param refImgURL the URL for the reference image.
     */
    public SVGRenderingAccuracyTest(String svgURL,
                                    String refImgURL){
        super(svgURL, refImgURL);
    }

    /**
     * For subclasses
     */
    protected SVGRenderingAccuracyTest(){
    }

    /**
     * If true, this test will use validation
     */
    public void setValidating(Boolean validate){
        if (validate == null){
            throw new IllegalArgumentException();
        }
        this.validate = validate;
    }

    public boolean getValidating(){
        return validate;
    }

    /**
     * Sets the userLanguage
     */
    public void setUserLanguage(String userLanguage){
        this.userLanguage = userLanguage;
    }

    public String getUserLanguage(){
        return this.userLanguage;
    }

    /**
     * Template method which subclasses can override if they
     * need to manipulate the DOM in some way before running 
     * the accuracy test. For example, this can be useful to 
     * test the alternate stylesheet support.
     */
    protected Document manipulateSVGDocument(Document doc) {
        return doc;
    }

    
    public TestReport encode(URL srcURL, FileOutputStream fos) {
        DefaultTestReport report = new DefaultTestReport(this);
        try{
            ImageTranscoder transcoder = getTestImageTranscoder();
            TranscoderInput src = new TranscoderInput(svgURL.toString());
            TranscoderOutput dst = new TranscoderOutput(fos);
            transcoder.transcode(src, dst);
            return null;
        }catch(TranscoderException e){
            StringWriter trace = new StringWriter();
            e.printStackTrace(new PrintWriter(trace));
                
            report.setErrorCode(ERROR_CANNOT_TRANSCODE_SVG);
            report.setDescription(new TestReport.Entry[]{
                new TestReport.Entry
                (Messages.formatMessage(ENTRY_KEY_ERROR_DESCRIPTION, null),
                 Messages.formatMessage(ERROR_CANNOT_TRANSCODE_SVG,
                                        new String[]{svgURL.toString(), 
                                                     e.getClass().getName(),
                                                     e.getMessage(),
                                                     trace.toString()
                                        })) });
        }catch(Exception e){
            StringWriter trace = new StringWriter();
            e.printStackTrace(new PrintWriter(trace));

            report.setErrorCode(ERROR_CANNOT_TRANSCODE_SVG);
            report.setDescription(new TestReport.Entry[]{
                new TestReport.Entry
                (Messages.formatMessage(ENTRY_KEY_ERROR_DESCRIPTION, null),
                 Messages.formatMessage(ERROR_CANNOT_TRANSCODE_SVG,
                                        new String[]{svgURL.toString(), 
                                                     e.getClass().getName(),
                                                     e.getMessage(),
                                                     trace.toString()
                                        })) });
        }
        report.setPassed(false);
        return report;
    }

    /**
     * Returns the <code>ImageTranscoder</code> the Test should
     * use
     */
    public ImageTranscoder getTestImageTranscoder(){
        ImageTranscoder t = new InternalPNGTranscoder();
        t.addTranscodingHint(PNGTranscoder.KEY_FORCE_TRANSPARENT_WHITE,
                             Boolean.FALSE);
        t.addTranscodingHint(PNGTranscoder.KEY_BACKGROUND_COLOR,
                             new Color(0,0,0,0));
        t.addTranscodingHint(PNGTranscoder.KEY_EXECUTE_ONLOAD,
                             Boolean.TRUE);

        if (validate){
            t.addTranscodingHint(PNGTranscoder.KEY_XML_PARSER_VALIDATING,
                                 Boolean.TRUE);
            t.addTranscodingHint(PNGTranscoder.KEY_XML_PARSER_CLASSNAME,
                                 VALIDATING_PARSER);
        }

        if (userLanguage != null){
            t.addTranscodingHint(PNGTranscoder.KEY_LANGUAGE, 
                                 userLanguage);
        }
        return t;
    }

    /**
     * Inner class which derives from the PNGTranscoder and calls the 
     * manipulateSVGDocument just before encoding happens.
     */
    protected class InternalPNGTranscoder extends PNGTranscoder{
        /**
         * Transcodes the specified Document as an image in the specified output.
         *
         * @param document the document to transcode
         * @param uri the uri of the document or null if any
         * @param output the ouput where to transcode
         * @exception TranscoderException if an error occured while transcoding
         */
        protected void transcode(Document document,
                                 String uri,
                                 TranscoderOutput output)
            throws TranscoderException {
            SVGRenderingAccuracyTest.this.manipulateSVGDocument(document);
            super.transcode(document, uri, output);
        }
    }
}