--- a/ZipStream.st	Thu Jun 05 11:15:06 2008 +0200
+++ b/ZipStream.st	Thu Jun 05 11:16:16 2008 +0200
@@ -139,6 +139,20 @@
 
 ! !
 
+!ZipStream class methodsFor:'instance creation'!
+
+readOpenAsZipStreamOn:aStream
+    "open to read data compressed from stream, 
+     the default readOpenOn: will open ZipStream as gzip stream"
+    ^ self basicNew streamOpenWithMode:#readonly on:aStream
+!
+
+writeOpenAsZipStreamOn:aStream
+    "open to write data compressed to stream, 
+     the default writeOpenOn: will open ZipStream as gzip stream"
+    ^ self basicNew streamOpenWithMode:#writeonly on:aStream
+! !
+
 !ZipStream class methodsFor:'ZipInterface compatibility - compress/uncompress'!
 
 compress: aUncompressedByteArray into: aCompressedByteArray
@@ -664,69 +678,69 @@
 !ZipStream methodsFor:'startup & release'!
 
 openWithMode:aMode on:aStream
-
+    "open stream and write or check gzip header"
     super openWithMode:aMode on:aStream.
     self isReadable ifTrue:[
-	"Check for the gzip magic id"
-	|flags|
+        "Check for the gzip magic id"
+        |flags|
 
-	GZ_MAGIC_ID do:[:b|
-	    onStream nextByte ~~ b ifTrue:[ self zerror:'version error' ]
-	].
+        GZ_MAGIC_ID do:[:b|
+            onStream nextByte ~~ b ifTrue:[ self zerror:'version error' ]
+        ].
 
-	onStream nextByte ~~ Z_DEFLATED ifTrue:[
-	    self zerror:'invalid method (not deflated)'
-	].
+        onStream nextByte ~~ Z_DEFLATED ifTrue:[
+            self zerror:'invalid method (not deflated)'
+        ].
 
-	flags := onStream nextByte.
-	(flags bitAnd:HEAD_RESERVED) ~~ 0 ifTrue:[
-	    self zerror:'wrong data format'
-	].
+        flags := onStream nextByte.
+        (flags bitAnd:HEAD_RESERVED) ~~ 0 ifTrue:[
+            self zerror:'wrong data format'
+        ].
 
-	"discard time, xflags and OS code"
-	onStream skip:6.
+        "discard time, xflags and OS code"
+        onStream skip:6.
 
-	(flags bitAnd:HEAD_EXTRA_FIELD) ~~ 0 ifTrue:[|len|
-	    "skip the extra field"
-	    len := onStream nextByte + (onStream nextByte bitShift:8).
-	    len timesRepeat:[ onStream nextByte ].
-	].
+        (flags bitAnd:HEAD_EXTRA_FIELD) ~~ 0 ifTrue:[|len|
+            "skip the extra field"
+            len := onStream nextByte + (onStream nextByte bitShift:8).
+            len timesRepeat:[ onStream nextByte ].
+        ].
 
-	(flags bitAnd:HEAD_ORIG_NAME) ~~ 0 ifTrue:[|b|
-	    "skip the original file name"
-	    [ (b := onStream nextByte) ~~ 0 ] whileTrue.
-	].
+        (flags bitAnd:HEAD_ORIG_NAME) ~~ 0 ifTrue:[|b|
+            "skip the original file name"
+            [ (b := onStream nextByte) ~~ 0 ] whileTrue.
+        ].
 
-	(flags bitAnd:HEAD_CRC) ~~ 0 ifTrue:[
-	    "skip the header crc"
-	    onStream skip:2.
-	].
+        (flags bitAnd:HEAD_CRC) ~~ 0 ifTrue:[
+            "skip the header crc"
+            onStream skip:2.
+        ].
     ] ifFalse:[
-	"write the gzip magic id
-	"
-	GZ_MAGIC_ID do:[:b| onStream nextPutByte:b ].
+        "write the gzip magic id
+        "
+        GZ_MAGIC_ID do:[:b| onStream nextPutByte:b ].
 
-	"write the method"
-	onStream nextPutByte:Z_DEFLATED.
+        "write the method"
+        onStream nextPutByte:Z_DEFLATED.
 
-	"write the flags"
-	onStream nextPutByte:0.
+        "write the flags"
+        onStream nextPutByte:0.
 
-	"write time"
-	4 timesRepeat:[ onStream nextPutByte:0 ].
+        "write time"
+        4 timesRepeat:[ onStream nextPutByte:0 ].
 
-	"write xflags"
-	onStream nextPutByte:0.
+        "write xflags"
+        onStream nextPutByte:0.
 
-	"write OS code"
-	onStream nextPutByte:HEAD_OS_CODE.
+        "write OS code"
+        onStream nextPutByte:HEAD_OS_CODE.
     ].
 ! !
 
 !ZipStream class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic2/ZipStream.st,v 1.28 2007-02-15 14:46:40 sr Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/ZipStream.st,v 1.29 2008-06-05 09:16:16 ab Exp $'
 ! !
 
 ZipStream initialize!