X11Ada

X11Ada is an Ada 95 binding to X11R5, to the Xlib, Xt, and Motif programming API's. It is a direct binding. The Ada 95 features it uses heavily are general access types and child packages, but there are no tagged types. The mapping is direct in the sense that there is mostly a 1-1 mapping between:

C header file: Ada package
C type: Ada type
C function: Ada function or procedure
C variable or constant: Ada variable or constant

Downloading

Extracting and building X11Ada takes about 20 megabytes of disk space. Building the software takes around an hour on a Sun-4.

In this release, the X11 and Xt components are available directly on the Web from two sites:

The Motif component is still only available in beta test form by sending a mail message to mg@inmet.com. The reason for separating these components is that the rights to distribute the Motif bindings are still being discussed with Open Software Foundation.

Building the installation

The software is in tar, gzip format. To extract it:

Fetch the file off the Web, into a file named x11ada.tar.gz
gzip -d x11ada.tar.gz
tar xvf x11ada.tar

If you also have gotten the Motif component via email,

Extract the mail file into motif.tar.gz.uu
uudecode motif.tar.gz.uu
gzip -d motif.tar.gz
tar xvf motif.tar

Then to build the binding on Sun-4, type:

sh build

To build it on another platform, see the section Building X11Ada on other platforms below.

Latest changes

X11Ada works with GNAT 3.01 on Sun-4.

The documentation files are now available in Microsoft Word (*.doc) format and Postscript format (*.ps).

The MRM functions are added to the Motif binding.

The Stdarg package has been ported to Sparc, Intel, HP, MIPS, PowerPC, and Alpha.

The copyright notices have been revised.

Online files

The "doc" directory contains online documentation files.

The "ada" directory contains source files for X11Ada.

The "c" directory contains the C header files from which the Ada was derived. These could be needed because the tool we used to translate the C headers to Ada left out the comments. If you want to take a look at the original comments that were in the C headers, the Ada files contain references like:

PointerMotionHintMask : constant := 128; -- X.h:108

which says that this Ada declaration corresponds to line 108 of the C header file X.h.

The "test" directory contains a few small test programs.

Documentation

The documentation files in the "doc" directory are:

x11ada.html: this file
roadmap: a map of the correspondence between Ada package names, Ada source files, and C header files
xbind.*: xbind.ps is the Postscript version of a technical report and overview of X11Ada; xbind.doc is the Microsoft Word version.
interf4.*: interf4.ps is the Postscript version of a paper about a Windows NT binding that was recently completed. The sections of the paper about variable-length argument lists and variable-length arrays are also relevant to the X binding. (Also, the section on treatment of C unions should be relevant, except the support for pragma Unchecked_Union is not yet implemented in GNAT 3.01 on Sparc.) Interf4.doc is the Microsoft Word version. This paper was published in the 1995 TriAda conference proceedings.
stdarg.*: stdarg.ps is the Postscript version of a paper about the Stdarg package of X11Ada; stdarg.doc is the Microsoft Word version.

Building X11Ada on other platforms

This release of X11Ada has been tested with GNAT 3.01 on Sun-4. The Stdarg family of packages are known to be machine-dependent. Versions are provided for the

Sun-4 Sparc
Intel 386-486-Pentium
Hewlett-Packard HP-9000 series 700 and 800
MIPS/Silicon Graphics
PowerPC
DEC Alpha

machine architectures. Here is how to build it for one of these platforms:

If you are building X11Ada on Sparc, do nothing special.
If you are building X11Ada on Intel, HP, or SGI edit the file stdarg-machine.ads and set the constant This_Arch to the correct value for your machine.
On Intel, there is a warning message about record alignment in the file stdarg-machine.ads. This message can be ignored.
If you are building on HP, the line #define STACK_GROWS_UP in the file var.c must be commented out. Also the rep clause for ArgBlock in stdarg.ads must be un-commented.
If you are building for the Alpha, the type Resource must be commented out of x.ads and x.adb.
If you are using another hardware platform, some rewriting of the Stdarg packages will be needed. To get started, see the stdarg.doc documentation file.

In the "test" directory, the "testvar" program tests that the Stdarg mechanism is working, and has been built correctly for the current machine platform.

As new releases of GNAT come out, and other Ada 95 compilers become available, small changes to X11Ada may be needed.

Test programs

Currently there are 5 small test programs:

testvar tests the Stdarg mechanism, as mentioned above, and gives examples of how to use this mechanism from an application program.
testexten tests the extensible array mechanism , and gives examples of how to use this mechanism from an application program.
basicwin is a simple Xlib program
xrowcolumn is a simple Xt program
hello_motif is a simple Motif program

The last three are translated from examples in the O'Reilly X programming manuals. Here is what these three are supposed to look like when run: basicwin, xrowcolumn, and hello_motif. There may be slight differences on your system.

Sending test comments and programs

More test programs are needed. Please send them! It's OK if they contain copyright notices, as long as the copyright text allows me to re-distribute the programs along with the general release of the binding.

Please send comments and test programs to:

Mitch Gart
Intermetrics
733 Concord Avenue
Cambridge, MA, 02138, USA
mg@inmet.com (email)
617-661-1840 (voice)
617-868-2843 (Fax)

X11Ada programming examples

For information on X11Ada programming see The Free X11/Ada 95 Programmer's Home Page.

Some programs have been contributed by users of the binding, see the contributions directory.

Changes

Last updated March 8, 1996.

March 4, 1996: upgrade to GNAT 3.03.

Feb 29, 1996: various small bug fixes. Add null_widget and other declarations for private types. Move Resource to package X.Tasking so the binding can be used on machines where tasking is not supported. Added contributions directory and Mandelbrot program. Fix AdaMagic compilation errors.

Dec 19, 1995: release that changes access subprograms to all have pragma Convention (C), and other small changes to make the binding work with the OCS compiler.