--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/software/eXist/mpdl-modules/src/de/mpg/mpiwg/berlin/mpdl/util/MpdlITextUserAgent.java	Wed Nov 24 17:24:23 2010 +0100
@@ -0,0 +1,149 @@
+package de.mpg.mpiwg.berlin.mpdl.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+
+import org.apache.log4j.Logger;
+import org.xhtmlrenderer.layout.SharedContext;
+import org.xhtmlrenderer.pdf.ITextFSImage;
+import org.xhtmlrenderer.pdf.ITextOutputDevice;
+import org.xhtmlrenderer.pdf.PDFAsImage;
+import org.xhtmlrenderer.resource.ImageResource;
+import org.xhtmlrenderer.swing.NaiveUserAgent;
+
+import com.lowagie.text.Image;
+import com.lowagie.text.Rectangle;
+import com.lowagie.text.pdf.PdfReader;
+
+public class MpdlITextUserAgent extends NaiveUserAgent {
+  private static final int IMAGE_CACHE_CAPACITY = 32;
+  private static final float DEFAULT_DOTS_PER_POINT = 20f * 4f / 3f;
+  private static Logger LOGGER = Logger.getLogger(MpdlITextUserAgent.class); // Logs to EXIST_HOME/webapp/WEB-INF/logs/exist.log
+  private SharedContext sharedContext;
+  private ITextOutputDevice outputDevice;
+  
+  public MpdlITextUserAgent() {
+    super(IMAGE_CACHE_CAPACITY);
+    outputDevice = new ITextOutputDevice(DEFAULT_DOTS_PER_POINT);
+  }
+  
+  @SuppressWarnings("unchecked")
+  public ImageResource getImageResource(String inputUri) {
+    ImageResource resource = null;
+    String uri = resolveURI(inputUri);
+    resource = (ImageResource) _imageCache.get(uri);
+    if (resource == null) {
+      InputStream is = resolveAndOpenStream(uri);
+      if (is != null) {
+        try {
+          URL url = new URL(uri);
+          if (url.getPath() != null && url.getPath().toLowerCase().endsWith(".pdf")) {
+            PdfReader reader = outputDevice.getReader(url);
+            PDFAsImage image = new PDFAsImage(url);
+            Rectangle rect = reader.getPageSizeWithRotation(1);
+            image.setInitialWidth(rect.getWidth()*outputDevice.getDotsPerPoint());
+            image.setInitialHeight(rect.getHeight()*outputDevice.getDotsPerPoint());
+            resource = new ImageResource(image);
+          } else {
+            Image image = getImage(url);
+            if (image == null)
+              return null;
+            scaleToOutputResolution(image);
+            resource = new ImageResource(new ITextFSImage(image));
+          }
+          _imageCache.put(uri, resource);
+        } catch (IOException e) {
+          LOGGER.error("Can't get image file: unexpected problem for URI: '" + uri + "': " + e.getMessage(), e);
+        } finally {
+          try {
+            if (is != null)
+              is.close();
+          } catch (IOException e) {
+            // ignore
+          }  
+        }
+      }
+    }
+    if (resource == null) {
+      resource = new ImageResource(null);
+    }
+    return resource;
+  }
+  
+  private void scaleToOutputResolution(Image image) {
+    float factor = sharedContext.getDotsPerPixel();
+    image.scaleAbsolute(image.getPlainWidth() * factor, image.getPlainHeight() * factor);
+  }
+
+  public SharedContext getSharedContext() {
+    return sharedContext;
+  }
+
+  public void setSharedContext(SharedContext sharedContext) {
+    this.sharedContext = sharedContext;
+  }
+  
+  private Image getImage(URL url) {
+    Image image = null;
+    try {
+      image = Image.getInstance(url);
+    } catch (Exception e) {
+      try {
+        Thread.sleep(1000);
+      } catch (InterruptedException ee) {
+        // nothing
+      }
+      LOGGER.error("first retry to get image for URL '" + url.toString() + "': " + e.getMessage(), e);
+      try {
+        image = Image.getInstance(url);
+      } catch (Exception e2) {
+        try {
+          Thread.sleep(1000);
+        } catch (InterruptedException ee) {
+          // nothing
+        }
+        LOGGER.error("second retry to get image for URL '" + url.toString() + "': " + e.getMessage(), e);
+        try {
+          image = Image.getInstance(url);
+        } catch (Exception e3) {
+          LOGGER.error("third retry to get image for URL '" + url.toString() + "': " + e.getMessage(), e);
+          return null;
+        }
+      }
+    }
+    return image;
+  }
+
+  protected InputStream resolveAndOpenStream(String inputUri) {
+    InputStream is = null;
+    String uri = resolveURI(inputUri);
+    try {
+      is = new URL(uri).openStream();
+    } catch (Exception e) {
+      try {
+        Thread.sleep(1000);
+      } catch (InterruptedException ee) {
+        // nothing
+      }
+      LOGGER.error("first retry to open stream for URL '" + uri + "': " + e.getMessage(), e);
+      try {
+        is = new URL(uri).openStream();
+      } catch (Exception e2) {
+        try {
+          Thread.sleep(1000);
+        } catch (InterruptedException ee) {
+          // nothing
+        }
+        LOGGER.error("second retry to open stream for URL '" + uri + "': " + e.getMessage(), e);
+        try {
+          is = new URL(uri).openStream();
+        } catch (Exception e3) {
+          LOGGER.error("third retry to open stream for URL '" + uri + "': " + e.getMessage(), e);
+          return null;
+        }
+      }
+    }
+    return is;
+  }
+}