Improved registration of ImageReader implementations.

line ending correction
ArrayList --> List

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/fop-0_20_2-maintain@195450 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/org/apache/fop/image/analyser/ImageReaderFactory.java b/src/org/apache/fop/image/analyser/ImageReaderFactory.java
index 271f83a81d00807dd7455d742fb40d574d005fc3..3d6896ed0b6b51dc2de58e15da55f42093c00524 100644 (file)
--- a/src/org/apache/fop/image/analyser/ImageReaderFactory.java
+++ b/src/org/apache/fop/image/analyser/ImageReaderFactory.java
@@ -1,6 +1,6 @@
 /*
  * $Id$
- * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
+ * Copyright (C) 2001-2002 The Apache Software Foundation. All rights reserved.
  * For details on use and redistribution please refer to the
  * LICENSE file included with these sources.
  */
@@ -11,7 +11,7 @@ package org.apache.fop.image.analyser;
 import java.io.InputStream;
 import java.io.BufferedInputStream;
 import java.io.IOException;
-import java.util.ArrayList;
+import java.util.List;
 
 // FOP
 import org.apache.fop.image.FopImageException;
@@ -19,13 +19,52 @@ import org.apache.fop.image.FopImageException;
 /**
  * Factory for ImageReader objects.
  * @author Pankaj Narula
- * @version 1.0
  */
 public class ImageReaderFactory {
-    static protected ArrayList formats = null;
+    static protected List formats = null;
+
+    static {
+        /**@todo  make configurable one day...*/
+        formats = new java.util.Vector();
+        try {
+            registerImageReader("org.apache.fop.image.analyser.JPEGReader");
+            registerImageReader("org.apache.fop.image.analyser.BMPReader");
+            registerImageReader("org.apache.fop.image.analyser.GIFReader");
+            registerImageReader("org.apache.fop.image.analyser.PNGReader");
+            registerImageReader("org.apache.fop.image.analyser.TIFFReader");
+            registerImageReader("org.apache.fop.image.analyser.EPSReader");
+            registerImageReader("org.apache.fop.image.analyser.SVGReader");
+        } catch (ClassNotFoundException cnfe) {
+            throw new RuntimeException("One of the default ImageReader implementations is not available: "+cnfe.getMessage());
+        }
+    }
+
+    /**
+     * Registers a new ImageReader implementation.
+     *
+     * @param classname The fully qualified classname
+     * @throws ClassNotFoundException In case the given class cannot be found
+     */
+    public static void registerImageReader(String classname) throws ClassNotFoundException {
+        Class clazz = Class.forName(classname);
+        registerImageReader(clazz);
+    }
+
+
+    /**
+     * Registers a new ImageReader implementation.
+     *
+     * @param clazz The ImageReader implementation class.
+     */
+    public static void registerImageReader(Class clazz) {
+        if (!ImageReader.class.isAssignableFrom(clazz)) throw new RuntimeException("This class does not implement the ImageReader interface: "+clazz.getName());
+        formats.add(clazz);
+    }
 
     /**
      * ImageReader maker.
+     *
+     * @param uri URI of the image
      * @param in image input stream
      * @return ImageReader object
      * @exception FopImageException  an error occured during creation or
@@ -34,22 +73,16 @@ public class ImageReaderFactory {
     static public ImageReader Make(String uri,
                                    InputStream in) throws FopImageException {
 
-        // need to use a config file and remove static methods
-        formats = new ArrayList();
-        formats.add(new JPEGReader());
-        formats.add(new BMPReader());
-        formats.add(new GIFReader());
-        formats.add(new PNGReader());
-        formats.add(new TIFFReader());
-        formats.add(new EPSReader());
-        formats.add(new SVGReader());
-        //
-
         ImageReader reader;
         BufferedInputStream bis = new BufferedInputStream(in);
         try {
             for (int i = 0; i< formats.size(); i++) {
-                reader = (ImageReader)formats.get(i);
+                Class clazz = (Class)formats.get(i);
+                try {
+                    reader = (ImageReader)clazz.newInstance();
+                } catch (Exception e) {
+                    throw new FopImageException("ImageReader implementation cannot be instantiated: "+e.getMessage());
+                }
                 if (reader.verifySignature(uri, bis)) {
                     return reader;
                 }