[BATIK-610] [PATCH] Compatibility with GNU Classpath

• Type: Improvement
• Status: Resolved
• Resolution: Fixed
• Affects Version/s: 1.8
• Component/s: (RFE) Request For Extension
• Labels: PatchAvailable
• Environment: Operating System: All; Platform: All
• Assignee: Batik Developer's Mailing list
• Reporter: Jeremias Maerki
• Created: 08/Jan/06 17:42
• Updated: 02/May/13 02:28
• Resolved: 05/Nov/09 16:56

Description

As discussed and promised some time ago, I finally managed to get everything
together and submit a patch to remove Batik's mandatory dependency on
Sun-private classes in its codec classes. This patch introduces adapter classes
to decouple the image decoding and encoding from the actual codec library used.
The "internal codecs" as I called them are moved to a new source directory
(sources-internal-codec), so their compilation can be made optional in an IDE
and in the Ant build. In addition to adapter classes handling image loading and
saving using these internal codecs, I've written implementations that use the
Image I/O API that is available under JDK 1.4 (and later) and in GNU Classpath.
Please note: So far I have not done any tests with GNU Classpath (GCJ, IKVM or
whatever) for Batik.

A few implementation notes:

• I've not reimplemented every single feature in the various image transcoders
  for the Image I/O API as is available for the internal codecs. Examples are
  Gamma/Chromaticity handling and background color in PNG.
• I've had endless loops in ImageIO.getImageWritersByMIMEType() and
  IIOMetadata.mergeTree() while trying to write TIFF images through the Image I/O
  API with the JAI Image I/O Tools in the classpath. (I think TIFF is only
  supported by Image I/O under a Sun JDK if the JAI Image I/O Tools are available)
  That means that there are probably a few bugs hidden in there. I didn't go too
  deep in order not to lose too much time.
• I've experienced problems handling metadata and encoding parameters when
  writing JPEG images through Image I/O. The current code works for most use
  cases, though.
• I created a new batik-codec.jar in the Ant build that contains the internal
  codec classes. I hope I got the dependencies right there.

In addition to the above topic, the patch contains the following changes:

• The TIFFTranscoder now supports specifying the compression method through a
  Transcoding hint (type String).
• I've changed the code that prepares an XML parser to use JAXP in order to
  remove the mandatory dependency on Apache Xerces. I hope I did this the right way.

Before applying the patch it is ESSENTIAL to do local SVN copy operations
(versioned copies) for the following files:
sources/org/apache/batik/ext/awt/image/spi/*RegistryEntry.java (-->
sources-internal-codec)
sources/org/apache/batik/ext/awt/image/codec/*/ (--> sources-internal-codec)
resources/org/apache/batik/ext/awt/image/codec/properties (-->
sources-internal-codec)

Please see the status-log.txt file in the ZIP I'll attach. It shows how exactly
I moved these classes (Watch for the "+").

Attaching the patch in a minute...

Issue Links

• depends upon: BATIK-885 Migrate from proprietary "com.sun.image" to "javax.imageio"