README This is the java-gnome language bindings project. We endeavour to provide a high quality library you can use to write GTK and GNOME programs. The underlying APIs are elegantly transformed into Java and carefully documented so that anyone new to Linux or Open Source can rapidly be on their way to creating fabulous applications. This README file is devoted to helping you get started building the bindings themselves. Building java-gnome =================== For the impatient: $ tar xjf java-gnome-4.0.9.tzr.bz2 $ cd java-gnome-4.0.9 $ ./configure $ make But there's a bunch of stuff you probably want to know, so read on! 1. Get the source code ---------------------- ### From a release tarball ### You can download the latest java-gnome release from the GNOME FTP server at: [`http://ftp.gnome.org/pub/gnome/sources/java-gnome/4.0/`][mirror] Once you've downloaded the latest source tarball: $ tar xjf java-gnome-4.0.9.tzr.bz2 $ cd java-gnome-4.0.9 And go on to step 2 for details about options you can pass to the configuration command. ### Or checkout the source ### If you want a newer version of the code than the tarball you might have, you can always check it out over the net. We use Bazaar (`bzr`), an advanced third-generation Distributed Version [or Revision] Control System, to manage our source code. Getting a checkout is easy: $ bzr init-repo java-gnome/ $ cd java-gnome/ $ bzr checkout bzr://research.operationaldynamics.com/bzr/java-gnome/mainline $ cd mainline/ 2. Run `./configure` -------------------- The top level directory contains a custom `./configure` which detects your Operating System variant, sets defaults accordingly, verifies the location of prerequisites (the various `.jar` files), and finally chooses a Java bytecode compiler and Java Virtual Machine runtime environment. The configuration output is a Makefile fragment which is written to `.config` and subsequently included by the top level `Makefile`. So run it already: $ ./configure ### Background ### The steps necessary to configure and build a Java project are quite different than those needed to construct a program written in a more traditional language. Unlike C, for example, there is no need to do substitution across the codebase nor to worry about conditional compilation; `#ifdef` is not something we do in Java. This is in no small part because the Java class libraries and the language itself have been remarkably stable. To build and run a Java program, however, three things are necessary: * locate pre-requisite libraries (`.jar`s), and form a `CLASSPATH`; * locate, validate, and select a Java compiler; and * locate, validate, and select a Java runtime. That's it! From there, often a single compiler invocation will take care of building an entire program, but these preconditions must be satisfied before compiling is possible. _(Incidentally, tools like Ant are no help with any of this -- it just takes care of the build part; and don't even think about suggesting the GNU autotools -- they are a complex, arcane, and bloated nightmare that don't address with the Java specific challenges at all)_. At the moment, we use Andrew Cowie's "Equivalence" build system, which is composed of a straight-forward (if somewhat overweight) Perl program along with a simple Makefile which together carry out the task of configuring and building the library. Right now, Gentoo Linux, Debian Linux, Fedora Core Linux, and Solaris Unix should be detected properly and result in working configurations. If you are running a different operating system or distribution, please contact us and we'll add it -- it's just a matter of identifying the location of a few things. Better yet, look in the `configure` Perl script -- the places where OS is switched are obvious, and just add what you need to add, and send us a patch. Hopefully in the not to distant future we will be able to switch to Robert Collins's new "Buildtool". His approach to configuration and building will revolutionize the Free and Open Source Software universe, and we look forward to participating in the development of his work. Meanwhile... ### Customizing build options ### You can override the choices `configure` makes by listing parameters on the command line, like this: $ ./configure compiler=ecj runtime=jamvm This facilitates easily switching between runtimes and compilers for testing. At the moment, the available selections are: * `compiler` `-->` javac, ecj, and gcj -C * `runtime` `-->` java, cacao, jamvm, cacao, gij, and kaffe The whole point of the Equivalence's `configure` script is to figure things out for you, but if it can't quite figure out where Java is, you can override it by specifying an alternate location to find a JDK using either of the following: * `jdk` -- where to find a traditional Java Development Kit, ie `JAVA_HOME` * `gcj` -- prefix of an alternate GCC install * `jamvm` -- path to the JamVM executable * `cacao` -- path to the CACAO executable Examples: $ ./configure $ ./configure jdk=/opt/sun-jdk-bin-1.6.0.07 $ ./configure jamvm=/home/joe/custom/bin/jamvm runtime=jamvm Your configuration is persistent across builds in that checkout, ie, `make clean` won't force you to reconfigure (though `make distclean` will). The `configure` script runs very quickly, so it's no big deal to switch settings by re-running it. 3. Build -------- Once you've configured, compiling java-gnome is as simple as running Make: $ make If you're having trouble with something as Make runs and need to debug it, you can try: $ V=1 make This will show you the actual commands being executed (ie, Make's normal behaviour, which we override for appearances sake and because otherwise the signal to noise ratio is terrible and you never see warnings). If you're still stumped, you might try having a look at `.config`, which is where all the Make variables come from. The build products end up in `tmp/`: `tmp/gtk-4.0.jar` `tmp/libgtkjni-4.0.9.so` That's actually enough to go on -- if you're using an IDE like Eclipse you can just tell it about the `.jar` and indicate that `tmp/` is the native library location and you can jump right to "Using the Bindings". Or you can install java-gnome somewhere. Doesn't matter, really. 4. Install ---------- java-gnome 4.0 has the standard `make install` behaviour, and the equally standard `--prefix` option to `./configure`. ### Installing locally Someone installing it locally (to your home directory, say) might do: $ ./configure prefix=/home/bloggins $ make install and you would end up with: `~/share/java/gtk-4.0.jar` `~/share/java/gtk.jar` `~/lib/libgtkjni-4.0.9.so` ### Installing to system (for people packaging the library for their distro) The `install` target understands the `DESTDIR` variable used by packagers to install to a specified prefix _within_ a temporary directory. Someone writing an `.ebuild` to create a package for java-gnome on a Gentoo system would probably end up seeing the following commands being run by Portage, for example: ... ./configure prefix=/usr make ... make DESTDIR=/var/tmp/portage/java-gnome-4.0.9-r2/image install ... With a prefix of `/usr` you will end up with `/usr/share/java/gtk-4.0.jar` `/usr/share/java/gtk.jar` `/usr/lib/libgtkjni-4.0.9.so` If you have distro policy issues to deal with, then move things around once they've landed in `DESTDIR`. Using the bindings ================== ### Running the "demo" There are a few _tiny_ and _trivial_ example programs in the `doc/examples/` directory of the bindings. If you would like to see one, you could compile and run it by hand, doing something like: $ javac -classpath tmp/gtk-4.0.jar -d tmp/tests doc/examples/button/ExamplePressMe.java $ java -classpath tmp/gtk-4.0.jar:tmp/tests button.ExamplePressMe This shows you how you can reference and use the library after it is built by `make` into `tmp/`. Of course, that was _way_ too much typing. Instead, just do this: $ make demo `:)`. As usual, use `V=1` to see what it is actually doing. ### Running your own programs java-gnome has a native component that links tightly against various GNOME libraries (after all, the whole point is to use the real GTK, not some pseudo look alike pathetic attempt of a widget toolkit), but we take care of locating it and loading it for you. So all you need to do to run an application is: $ java -client -ea \ -classpath /home/bloggins/share/java/gtk.jar \ com.example.ComeOnBabyLightMyFire Oh, the joys of running Java programs by hand. Status ====== java-gnome 4.0 is now a solid foundation that has been used to develop non-trivial applications. The architecture and internal design has been well proved, and the coverage level (relative to the full breadth of the underlying libraries) is reaching maturity. Get Involved ------------ If you would like to get involved in 4.0 yourself as an individual, we would welcome your contribution. See [`HACKING`](HACKING.html). If you are working on an application, want to learn more, or are just curious, join us online in `#java-gnome` on `irc.gimp.net`. Funding ------- Most of all, financial support is necessary to fund the continued development of the bindings infrastructure and the programmers needed to quickly achieve the coverage level everyone wishes. If you feel that you would like to be a part of seeing the Java bindings for GNOME be a success, your timely choice to contribute to funding the project would be a significant contribution to bringing the wider Java community to the world of Open Source and Software Freedom. Happy coding! AfC `--` Andrew Frederick Cowie Managing Director, [Operational Dynamics](http://www.operationaldynamics.com/), a Change Management consultancy... Maintainer, [java-gnome](http://java-gnome.sourceforge.net/), opening GTK and GNOME to Java programmers! _Last modified 12 Sep 08_ [mirror]: http://ftp.gnome.org/pub/gnome/sources/java-gnome/4.0/