fop/src/java/org/apache/fop/render/ps/PSImageUtils.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.
 */

/* $Id$ */

package org.apache.fop.render.ps;

import java.awt.Rectangle;
import java.awt.geom.Rectangle2D;
import java.io.IOException;

import org.apache.xmlgraphics.image.loader.ImageFlavor;
import org.apache.xmlgraphics.image.loader.ImageInfo;
import org.apache.xmlgraphics.image.loader.ImageManager;
import org.apache.xmlgraphics.image.loader.pipeline.ImageProviderPipeline;
import org.apache.xmlgraphics.ps.DSCConstants;
import org.apache.xmlgraphics.ps.PSGenerator;
import org.apache.xmlgraphics.ps.PSResource;

import org.apache.fop.render.ImageHandlerRegistry;
import org.apache.fop.render.RenderingContext;

/**
 * Utility code for rendering images in PostScript.
 */
public class PSImageUtils extends org.apache.xmlgraphics.ps.PSImageUtils {

    /**
     * Indicates whether the given image (identified by an {@link ImageInfo} object) shall be
     * inlined rather than generated as a PostScript form.
     * @param info the info object for the image
     * @param renderingContext the rendering context
     * @return true if the image shall be inlined, false if forms shall be used.
     */
    public static boolean isImageInlined(ImageInfo info, PSRenderingContext renderingContext) {
        String uri = info.getOriginalURI();
        if (uri == null || "".equals(uri)) {
            return true;
        }
        //Investigate choice for inline mode
        ImageFlavor[] inlineFlavors = determineSupportedImageFlavors(renderingContext);
        ImageManager manager = renderingContext.getUserAgent().getFactory().getImageManager();
        ImageProviderPipeline[] inlineCandidates
            = manager.getPipelineFactory().determineCandidatePipelines(
                    info, inlineFlavors);
        ImageProviderPipeline inlineChoice = manager.choosePipeline(inlineCandidates);
        ImageFlavor inlineFlavor = (inlineChoice != null
                ? inlineChoice.getTargetFlavor() : null);

        //Create a rendering context for form creation
        PSRenderingContext formContext = renderingContext.toFormContext();

        //Investigate choice for form mode
        ImageFlavor[] formFlavors = determineSupportedImageFlavors(formContext);
        ImageProviderPipeline[] formCandidates
            = manager.getPipelineFactory().determineCandidatePipelines(
                    info, formFlavors);
        ImageProviderPipeline formChoice = manager.choosePipeline(formCandidates);
        ImageFlavor formFlavor = (formChoice != null ? formChoice.getTargetFlavor() : null);

        //Inline if form is not supported or if a better choice is available with inline mode
        return formFlavor == null || !formFlavor.equals(inlineFlavor);
    }

    private static ImageFlavor[] determineSupportedImageFlavors(RenderingContext renderingContext) {
        ImageFlavor[] inlineFlavors;
        ImageHandlerRegistry imageHandlerRegistry
            = renderingContext.getUserAgent().getFactory().getImageHandlerRegistry();
        inlineFlavors = imageHandlerRegistry.getSupportedFlavors(renderingContext);
        return inlineFlavors;
    }

    /**
     * Draws a form at a given location.
     * @param form the form resource
     * @param info the image info object representing the image in the form
     * @param rect the target rectangle (coordinates in millipoints)
     * @param generator the PostScript generator
     * @throws IOException if an I/O error occurs
     */
    public static void drawForm(PSResource form, ImageInfo info, Rectangle rect,
            PSGenerator generator) throws IOException {
        Rectangle2D targetRect = new Rectangle2D.Double(
            rect.getMinX() / 1000.0,
            rect.getMinY() / 1000.0,
            rect.getWidth() / 1000.0,
            rect.getHeight() / 1000.0);
        generator.saveGraphicsState();
        translateAndScale(generator,
            info.getSize().getDimensionPt(), targetRect);

        //The following %%IncludeResource marker is needed later by ResourceHandler!
        generator.writeDSCComment(DSCConstants.INCLUDE_RESOURCE, form);
        generator.getResourceTracker().notifyResourceUsageOnPage(form);

        generator.writeln(form.getName() + " execform");
        generator.restoreGraphicsState();
    }


}