fop/src/java/org/apache/fop/render/ps/PSTranscoder.java

/*
 * $Id: PDFTranscoder.java,v 1.24 2003/03/07 09:51:26 jeremias Exp $
 * ============================================================================
 *                    The Apache Software License, Version 1.1
 * ============================================================================
 *
 * Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. The end-user documentation included with the redistribution, if any, must
 *    include the following acknowledgment: "This product includes software
 *    developed by the Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself, if
 *    and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "FOP" and "Apache Software Foundation" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache", nor may
 *    "Apache" appear in their name, without prior written permission of the
 *    Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
 * DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ============================================================================
 *
 * This software consists of voluntary contributions made by many individuals
 * on behalf of the Apache Software Foundation and was originally created by
 * James Tauber <jtauber@jtauber.com>. For more information on the Apache
 * Software Foundation, please see <http://www.apache.org/>.
 */
package org.apache.fop.render.ps;


import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;

import java.awt.Color;

import java.net.MalformedURLException;
import java.net.URL;

import java.io.IOException;

import org.apache.batik.bridge.BridgeContext;
import org.apache.batik.bridge.BridgeException;
import org.apache.batik.bridge.GVTBuilder;
import org.apache.batik.bridge.SVGTextElementBridge;
import org.apache.batik.bridge.ViewBox;

import org.apache.batik.dom.svg.SVGOMDocument;

import org.apache.batik.gvt.GraphicsNode;

import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.resources.Messages;

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

import org.apache.fop.svg.AbstractFOPTranscoder;

import org.apache.batik.gvt.TextPainter;
import org.apache.batik.gvt.renderer.StrokingTextPainter;

import org.w3c.dom.Document;
import org.w3c.dom.svg.SVGDocument;
import org.w3c.dom.svg.SVGSVGElement;

/**
 * This class enables to transcode an input to a PostScript document.
 *
 * <p>Two transcoding hints (<tt>KEY_WIDTH</tt> and
 * <tt>KEY_HEIGHT</tt>) can be used to respectively specify the image
 * width and the image height. If only one of these keys is specified,
 * the transcoder preserves the aspect ratio of the original image.
 *
 * <p>The <tt>KEY_BACKGROUND_COLOR</tt> defines the background color
 * to use for opaque image formats, or the background color that may
 * be used for image formats that support alpha channel.
 *
 * <p>The <tt>KEY_AOI</tt> represents the area of interest to paint
 * in device space.
 *
 * <p>Three additional transcoding hints that act on the SVG
 * processor can be specified:
 *
 * <p><tt>KEY_LANGUAGE</tt> to set the default language to use (may be
 * used by a &lt;switch> SVG element for example),
 * <tt>KEY_USER_STYLESHEET_URI</tt> to fix the URI of a user
 * stylesheet, and <tt>KEY_PIXEL_TO_MM</tt> to specify the pixel to
 * millimeter conversion factor.
 *
 * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a>
 * @author <a href="mailto:jeremias@apache.org">Jeremias Maerki</a>
 * @version $Id: PDFTranscoder.java,v 1.24 2003/03/07 09:51:26 jeremias Exp $
 */
public class PSTranscoder extends AbstractFOPTranscoder {

    /**
     * Constructs a new <tt>PSTranscoder</tt>.
     */
    public PSTranscoder() {
        super();
    }

    /**
     * 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 {

        if (!(document instanceof SVGOMDocument)) {
            throw new TranscoderException(Messages.formatMessage("notsvg",
                    null));
        }
        SVGDocument svgDoc = (SVGDocument)document;
        SVGSVGElement root = svgDoc.getRootElement();
        // initialize the SVG document with the appropriate context
        String parserClassname = (String)hints.get(KEY_XML_PARSER_CLASSNAME);

        PSDocumentGraphics2D graphics = new PSDocumentGraphics2D(false);

        // build the GVT tree
        GVTBuilder builder = new GVTBuilder();
        BridgeContext ctx = new BridgeContext(userAgent);
        TextPainter textPainter = null;
        textPainter = new StrokingTextPainter();
        ctx.setTextPainter(textPainter);

        SVGTextElementBridge textElementBridge =
                new PSTextElementBridge(graphics.getFontInfo());
        ctx.putBridge(textElementBridge);

        //PDFAElementBridge pdfAElementBridge = new PDFAElementBridge();
        //AffineTransform currentTransform = new AffineTransform(1, 0, 0, 1, 0, 0);
        //pdfAElementBridge.setCurrentTransform(currentTransform);
        //ctx.putBridge(pdfAElementBridge);

        //ctx.putBridge(new PSImageElementBridge());
        GraphicsNode gvtRoot;
        try {
            gvtRoot = builder.build(ctx, svgDoc);
        } catch (BridgeException ex) {
            throw new TranscoderException(ex);
        }
        // get the 'width' and 'height' attributes of the SVG document
        float docWidth = (float)ctx.getDocumentSize().getWidth();
        float docHeight = (float)ctx.getDocumentSize().getHeight();
        ctx = null;
        builder = null;

        // compute the image's width and height according the hints
        float imgWidth = -1;
        if (hints.containsKey(ImageTranscoder.KEY_WIDTH)) {
            imgWidth =
                ((Float)hints.get(ImageTranscoder.KEY_WIDTH)).floatValue();
        }
        float imgHeight = -1;
        if (hints.containsKey(ImageTranscoder.KEY_HEIGHT)) {
            imgHeight =
                ((Float)hints.get(ImageTranscoder.KEY_HEIGHT)).floatValue();
        }
        float width, height;
        if (imgWidth > 0 && imgHeight > 0) {
            width = imgWidth;
            height = imgHeight;
        } else if (imgHeight > 0) {
            width = (docWidth * imgHeight) / docHeight;
            height = imgHeight;
        } else if (imgWidth > 0) {
            width = imgWidth;
            height = (docHeight * imgWidth) / docWidth;
        } else {
            width = docWidth;
            height = docHeight;
        }
        // compute the preserveAspectRatio matrix
        AffineTransform px;
        String ref = null;
        try {
            ref = new URL(uri).getRef();
        } catch (MalformedURLException ex) {
            // nothing to do, catched previously
        }

        try {
            px = ViewBox.getViewTransform(ref, root, width, height);
        } catch (BridgeException ex) {
            throw new TranscoderException(ex);
        }

        if (px.isIdentity() && (width != docWidth || height != docHeight)) {
            // The document has no viewBox, we need to resize it by hand.
            // we want to keep the document size ratio
            float d = Math.max(docWidth, docHeight);
            float dd = Math.max(width, height);
            float scale = dd / d;
            px = AffineTransform.getScaleInstance(scale, scale);
        }
        // take the AOI into account if any
        if (hints.containsKey(ImageTranscoder.KEY_AOI)) {
            Rectangle2D aoi = (Rectangle2D)hints.get(ImageTranscoder.KEY_AOI);
            // transform the AOI into the image's coordinate system
            aoi = px.createTransformedShape(aoi).getBounds2D();
            AffineTransform mx = new AffineTransform();
            double sx = width / aoi.getWidth();
            double sy = height / aoi.getHeight();
            mx.scale(sx, sy);
            double tx = -aoi.getX();
            double ty = -aoi.getY();
            mx.translate(tx, ty);
            // take the AOI transformation matrix into account
            // we apply first the preserveAspectRatio matrix
            px.preConcatenate(mx);
        }
        // prepare the image to be painted
        int w = (int)width;
        int h = (int)height;

        try {
            graphics.setupDocument(output.getOutputStream(), w, h);
            graphics.setSVGDimension(docWidth, docHeight);

            if (hints.containsKey(ImageTranscoder.KEY_BACKGROUND_COLOR)) {
                graphics.setBackgroundColor((Color)hints.get(ImageTranscoder.KEY_BACKGROUND_COLOR));
            }
            graphics.setGraphicContext(new org.apache.batik.ext.awt.g2d.GraphicContext());
            graphics.setTransform(px);

            gvtRoot.paint(graphics);

            graphics.finish();
        } catch (IOException ex) {
            throw new TranscoderException(ex);
        }
    }

}