From d8e07e5b8b00bd32ac7136757098357b909d64e4 Mon Sep 17 00:00:00 2001
From: Jeremias Maerki <jeremias@apache.org>
Date: Thu, 9 Jun 2005 12:50:14 +0000
Subject: [PATCH] Avoid NPEs when no filename is set on the UserAgent. Only the
 first page is rendered in this case. The resolution is written to the PNG
 file.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@198730 13f79535-47bb-0310-9956-ffa450edef68
---
 .../apache/fop/render/bitmap/PNGRenderer.java | 61 +++++++++++++------
 1 file changed, 42 insertions(+), 19 deletions(-)

diff --git a/src/java/org/apache/fop/render/bitmap/PNGRenderer.java b/src/java/org/apache/fop/render/bitmap/PNGRenderer.java
index 1e2820886..28824e9ea 100644
--- a/src/java/org/apache/fop/render/bitmap/PNGRenderer.java
+++ b/src/java/org/apache/fop/render/bitmap/PNGRenderer.java
@@ -25,7 +25,7 @@ public class PNGRenderer extends Java2DRenderer {
     public static final String MIME_TYPE = "image/png";
 
     /** The file syntax prefix, eg. "page" will output "page1.png" etc */
-    private String fileSyntax;
+    private String filePrefix;
 
     /** The output directory where images are to be written */
     private File outputDir;
@@ -60,16 +60,22 @@ public class PNGRenderer extends Java2DRenderer {
 
         // the file provided on the command line
         File f = getUserAgent().getOutputFile();
-
-        outputDir = f.getParentFile();
-
-        // extracting file name syntax
-        String s = f.getName();
-        int i = s.lastIndexOf(".");
-        if (s.charAt(i - 1) == '1') {
-            i--; // getting rid of the "1"
+        if (f == null) {
+            //No filename information available. Only the first page will be rendered.
+            outputDir = null;
+            filePrefix = null;
+        } else {
+            outputDir = f.getParentFile();
+
+            // extracting file name syntax
+            String s = f.getName();
+            int i = s.lastIndexOf(".");
+            if (s.charAt(i - 1) == '1') {
+                i--; // getting rid of the "1"
+            }
+            filePrefix = s.substring(0, i);
         }
-        fileSyntax = s.substring(0, i);
+
     }
 
     public void stopRenderer() throws IOException {
@@ -78,14 +84,27 @@ public class PNGRenderer extends Java2DRenderer {
 
         for (int i = 0; i < pageViewportList.size(); i++) {
 
+            OutputStream os = getCurrentOutputStream(i);
+            if (os == null) {
+                getLogger().warn("No filename information available."
+                        + " Stopping early after the first page.");
+                break;
+            }
             // Do the rendering: get the image for this page
             RenderedImage image = (RenderedImage) getPageImage((PageViewport) pageViewportList
                     .get(i));
 
             // Encode this image
-            getLogger().debug("Encoding  Page " + (i + 1));
+            getLogger().debug("Encoding page " + (i + 1));
             renderParams = PNGEncodeParam.getDefaultEncodeParam(image);
-            OutputStream os = getCurrentOutputStream(i);
+            
+            // Set resolution
+            float pixSzMM = userAgent.getPixelUnitToMillimeter();
+            // num Pixs in 1 Meter
+            int numPix = (int)((1000 / pixSzMM) + 0.5);
+            renderParams.setPhysicalDimension(numPix, numPix, 1); // 1 means 'pix/meter'
+            
+            // Encode PNG image
             PNGImageEncoder encoder = new PNGImageEncoder(os, renderParams);
             encoder.encode(image);
             os.flush();
@@ -103,14 +122,18 @@ public class PNGRenderer extends Java2DRenderer {
             return firstOutputStream;
         }
 
-        File f = new File(outputDir + File.separator + fileSyntax
-                + (pageNumber + 1) + ".png");
-        try {
-            OutputStream os = new BufferedOutputStream(new FileOutputStream(f));
-            return os;
-        } catch (FileNotFoundException e) {
-            new FOPException("Can't build the OutputStream\n" + e);
+        if (filePrefix == null) {
             return null;
+        } else {
+            File f = new File(outputDir + File.separator + filePrefix
+                    + (pageNumber + 1) + ".png");
+            try {
+                OutputStream os = new BufferedOutputStream(new FileOutputStream(f));
+                return os;
+            } catch (FileNotFoundException e) {
+                new FOPException("Can't build the OutputStream\n" + e);
+                return null;
+            }
         }
     }
 }
-- 
2.39.5