Inline SVGs for PDFs (OX-9272)

pom.xml

@@ -107,6 +107,13 @@
             <version>1.17.2</version>
         </dependency>
 
+        <!-- Used to render SVG into PDF -->
+        <dependency>
+            <groupId>org.apache.xmlgraphics</groupId>
+            <artifactId>batik-all</artifactId>
+            <version>1.18</version>
+        </dependency>
+
         <!-- POI is used to generate excel exports -->
         <dependency>
             <groupId>org.apache.poi</groupId>

src/main/java/sirius/web/templates/pdf/ImageReplacedElementFactory.java

@@ -8,6 +8,7 @@
 
 package sirius.web.templates.pdf;
 
+import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.xhtmlrenderer.extend.ReplacedElement;
 import org.xhtmlrenderer.extend.UserAgentCallback;
@@ -20,18 +21,25 @@
 import sirius.kernel.health.Exceptions;
 import sirius.web.templates.pdf.handlers.PdfReplaceHandler;
 
+import javax.annotation.Nonnull;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
 import java.util.List;
 import java.util.Optional;
 
 /**
- * Used by the XHTMLRenderer (creating PDFs) to replace img elements by their referenced image.
+ * Used by the XHTMLRenderer (creating PDFs) to replace {@code img} elements by their referenced image and to render
+ * inline {@code svg} elements.
  * <p>
  * Alongside http different URI protocols are supported. These are handled by classes extending
  * {@link PdfReplaceHandler}.
  */
 public class ImageReplacedElementFactory extends ITextReplacedElementFactory {
 
     private static final String TAG_TYPE_IMG = "img";
+    private static final String TAG_TYPE_SVG = "svg";
+
     private static final String ATTR_SRC = "src";
 
     @PriorityParts(PdfReplaceHandler.class)
@@ -57,25 +65,60 @@ public ReplacedElement createReplacedElement(LayoutContext layoutContext,
             return null;
         }
 
+        return this.tryCreateReplacedImageElement(element, userAgentCallback, cssWidth, cssHeight)
+                   .or(() -> this.tryCreateReplacedSvgElement(element, cssWidth, cssHeight))
+                   .orElseGet(() -> super.createReplacedElement(layoutContext,
+                                                                box,
+                                                                userAgentCallback,
+                                                                cssWidth,
+                                                                cssHeight));
+    }
+
+    private Optional<ReplacedElement> tryCreateReplacedSvgElement(@Nonnull Element element,
+                                                                  int cssWidth,
+                                                                  int cssHeight) {
+        String nodeName = element.getNodeName();
+        if (!TAG_TYPE_SVG.equals(nodeName)) {
+            return Optional.empty();
+        }
+
+        try {
+            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
+            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
+
+            Document svgDocument = documentBuilder.newDocument();
+            Element svgElement = (Element) svgDocument.importNode(element, true);
+            svgDocument.appendChild(svgElement);
+
+            return Optional.of(new InlinedSvgElement(svgDocument, cssWidth, cssHeight));
+        } catch (ParserConfigurationException exception) {
+            Exceptions.handle(exception);
+            return Optional.empty();
+        }
+    }
+
+    private Optional<ReplacedElement> tryCreateReplacedImageElement(@Nonnull Element element,
+                                                                    UserAgentCallback userAgentCallback,
+                                                                    int cssWidth,
+                                                                    int cssHeight) {
         String nodeName = element.getNodeName();
         if (!TAG_TYPE_IMG.equals(nodeName)) {
-            return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
+            return Optional.empty();
         }
 
         String source = rewriteLegacyUrl(element.getAttribute(ATTR_SRC));
         if (Strings.isEmpty(source)) {
-            return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
+            return Optional.empty();
         }
 
         try {
             String protocol = Strings.split(source, "://").getFirst();
             PdfReplaceHandler handler = findHandler(protocol);
-            return new AsyncLoadedImageElement(handler, userAgentCallback, source, cssWidth, cssHeight);
+            return Optional.of(new AsyncLoadedImageElement(handler, userAgentCallback, source, cssWidth, cssHeight));
         } catch (Exception exception) {
             Exceptions.handle(exception);
+            return Optional.empty();
         }
-
-        return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
     }
 
     private PdfReplaceHandler findHandler(String protocol) {

src/main/java/sirius/web/templates/pdf/InlinedSvgElement.java

@@ -0,0 +1,120 @@
+/*
+ * Made with all the love in the world
+ * by scireum in Remshalden, Germany
+ *
+ * Copyright by scireum GmbH
+ * http://www.scireum.de - info@scireum.de
+ */
+
+package sirius.web.templates.pdf;
+
+import com.lowagie.text.pdf.PdfContentByte;
+import com.lowagie.text.pdf.PdfTemplate;
+import org.apache.batik.transcoder.TranscoderInput;
+import org.apache.batik.transcoder.print.PrintTranscoder;
+import org.w3c.dom.Document;
+import org.xhtmlrenderer.css.style.CalculatedStyle;
+import org.xhtmlrenderer.layout.LayoutContext;
+import org.xhtmlrenderer.pdf.ITextOutputDevice;
+import org.xhtmlrenderer.pdf.ITextReplacedElement;
+import org.xhtmlrenderer.render.BlockBox;
+import org.xhtmlrenderer.render.PageBox;
+import org.xhtmlrenderer.render.RenderingContext;
+
+import java.awt.Graphics2D;
+import java.awt.Point;
+import java.awt.print.PageFormat;
+import java.awt.print.Paper;
+
+/**
+ * Represents an SVG element that is inlined into the PDF.
+ * <p>
+ * The SVG is rendered into a PDF template via Apache Batik and then placed into the PDF.
+ *
+ * @see <a href="https://stackoverflow.com/questions/37056791/svg-integration-in-pdf-using-flying-saucer">Stackoverflow</a>
+ */
+public class InlinedSvgElement implements ITextReplacedElement {
+
+    private final Point location = new Point(0, 0);
+    private final Document svg;
+    private final int cssWidth;
+    private final int cssHeight;
+
+    protected InlinedSvgElement(Document svg, int cssWidth, int cssHeight) {
+        this.svg = svg;
+        this.cssWidth = cssWidth;
+        this.cssHeight = cssHeight;
+    }
+
+    @Override
+    public void paint(RenderingContext renderingContext, ITextOutputDevice outputDevice, BlockBox blockBox) {
+        PdfContentByte contentByte = outputDevice.getWriter().getDirectContent();
+        float width = cssWidth / outputDevice.getDotsPerPoint();
+        float height = cssHeight / outputDevice.getDotsPerPoint();
+
+        Paper paper = new Paper();
+        paper.setSize(width, height);
+        paper.setImageableArea(0, 0, width, height);
+
+        PageFormat pageFormat = new PageFormat();
+        pageFormat.setPaper(paper);
+
+        PdfTemplate template = contentByte.createTemplate(width, height);
+        Graphics2D graphics = template.createGraphics(width, height);
+        PrintTranscoder printTranscoder = new PrintTranscoder();
+        TranscoderInput transcoderInput = new TranscoderInput(svg);
+        printTranscoder.transcode(transcoderInput, null);
+        printTranscoder.print(graphics, pageFormat, 0);
+        graphics.dispose();
+
+        PageBox page = renderingContext.getPage();
+        float x = (float) blockBox.getAbsX() + page.getMarginBorderPadding(renderingContext, CalculatedStyle.LEFT);
+        float y = (float) (page.getBottom() - (blockBox.getAbsY() + cssHeight)) + page.getMarginBorderPadding(
+                renderingContext,
+                CalculatedStyle.BOTTOM);
+        x /= outputDevice.getDotsPerPoint();
+        y /= outputDevice.getDotsPerPoint();
+
+        contentByte.addTemplate(template, x, y);
+    }
+
+    @Override
+    public int getIntrinsicWidth() {
+        return cssWidth;
+    }
+
+    @Override
+    public int getIntrinsicHeight() {
+        return cssHeight;
+    }
+
+    @Override
+    public Point getLocation() {
+        return location;
+    }
+
+    @Override
+    public void setLocation(int x, int y) {
+        location.setLocation(x, y);
+    }
+
+    @Override
+    public void detach(LayoutContext layoutContext) {
+        // nothing to do
+    }
+
+    @Override
+    public boolean isRequiresInteractivePaint() {
+        return false;
+    }
+
+    @Override
+    public boolean hasBaseline() {
+        return false;
+    }
+
+    @Override
+    public int getBaseline() {
+        return 0;
+    }
+}