--- a/dwt/internal/image/PngDecodingDataStream.d	Fri Sep 12 13:53:21 2008 +0200
+++ b/dwt/internal/image/PngDecodingDataStream.d	Sun Sep 14 01:45:57 2008 +0200
@@ -7,26 +7,31 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
  *******************************************************************************/
-module dwt.internal.image;
+module dwt.internal.image.PngDecodingDataStream;
 
 
-import java.io.IOException;
-import java.io.InputStream;
+import dwt.dwthelper.InputStream;
 
 import dwt.DWT;
+import dwt.internal.image.PngLzBlockReader;
 
 public class PngDecodingDataStream : InputStream {
+
+    alias InputStream.read read;
+
     InputStream stream;
     byte currentByte;
     int nextBitIndex;
-    
+
     PngLzBlockReader lzBlockReader;
     int adlerValue;
-    
+
     static final int PRIME = 65521;
-    static final int MAX_BIT = 7;       
-    
+    static final int MAX_BIT = 7;
+
 this(InputStream stream) {
     super();
     this.stream = stream;
@@ -40,7 +45,7 @@
 /**
  * This method should be called when the image decoder thinks
  * that all of the compressed image data has been read. This
- * method will ensure that the next data value is an end of 
+ * method will ensure that the next data value is an end of
  * block marker. If there are more blocks after this one,
  * the method will read them and ensure that they are empty.
  */
@@ -48,7 +53,7 @@
     lzBlockReader.assertCompressedDataAtEnd();
 }
 
-public void close() {
+public override void close() {
     assertImageDataAtEnd();
     checkAdler();
 }
@@ -69,7 +74,7 @@
     return (currentByte & (1 << nextBitIndex)) >> nextBitIndex++;
 }
 
-byte getNextIdatByte() { 
+byte getNextIdatByte() {
     byte nextByte = cast(byte)stream.read();
     nextBitIndex = MAX_BIT + 1;
     return nextByte;
@@ -84,13 +89,13 @@
     adlerValue = (high << 16) | low;
 }
 
-public int read() {
+public override int read() {
     byte nextDecodedByte = lzBlockReader.getNextByte();
     updateAdler(nextDecodedByte);
     return nextDecodedByte & 0xFF;
 }
 
-public int read(byte[] buffer, int off, int len) {
+public override int read(byte[] buffer, int off, int len) {
     for (int i = 0; i < len; i++) {
         int b = read();
         if (b is -1) return i;
@@ -106,29 +111,30 @@
 private void readCompressedDataHeader() {
     byte headerByte1 = getNextIdatByte();
     byte headerByte2 = getNextIdatByte();
-    
+
     int number = ((headerByte1 & 0xFF) << 8) | (headerByte2 & 0xFF);
     if (number % 31 !is 0) error();
-    
+
     int compressionMethod = headerByte1 & 0x0F;
     if (compressionMethod !is 8) error();
-    
+
     int windowSizeHint = (headerByte1 & 0xF0) >> 4;
     if (windowSizeHint > 7) error();
     int windowSize = (1 << (windowSizeHint + 8));
     lzBlockReader.setWindowSize(windowSize);
-    
+
     int dictionary = (headerByte2 & (1 << 5));
     if (dictionary !is 0) error();
-    
+
 //  int compressionLevel = (headerByte2 & 0xC0) >> 6;
 }
 
 void checkAdler() {
-    int storedAdler = ((getNextIdatByte() & 0xFF) << 24)
-        | ((getNextIdatByte() & 0xFF) << 16)
-        | ((getNextIdatByte() & 0xFF) << 8)
-        | (getNextIdatByte() & 0xFF);
+    int storedAdler = 0;
+    storedAdler |= ((getNextIdatByte() & 0xFF) << 24);
+    storedAdler |= ((getNextIdatByte() & 0xFF) << 16);
+    storedAdler |= ((getNextIdatByte() & 0xFF) << 8);
+    storedAdler |=  (getNextIdatByte() & 0xFF);
     if (storedAdler !is adlerValue) error();
 }