gtkbuilder and Mac OS X

[vmagnin]

Paul F. built gtk-fortran on a MacBook Pro with a Core2Duo running the latest MacOSX 10.6.7
(Darwin 10.7.0 on x86_64), gtk 2.24.4 quartz version as well as gfortran 4.6 using macports. You can see some screenshots on the wiki.

The only problems are that gtkbuilder did not launch properly (he killed it after 5 minutes), and issued two
messages:

(gtkbuilder.f90.out:1578): Gtk-CRITICAL **: gtk_builder_add_from_file: assertion
`error == NULL || *error == NULL' failed
(gtkbuilder.f90.out:1578): Gtk-CRITICAL **: gtk_widget_show: assertion
`GTK_IS_WIDGET (widget)' failed

Same for gtkbuilder2:

(gtkbuilder2.f90.out:1601): Gtk-CRITICAL **: gtk_builder_add_from_file:
assertion `error == NULL || *error == NULL' failed
(gtkbuilder2.f90.out:1601): Gtk-CRITICAL **: gtk_widget_show: assertion
`GTK_IS_WIDGET (widget)' failed

They were launched from the examples/ directory.
Any idea ?

[vmagnin]

I also had a problem with gtkbuilder2.f90 under Windows 7 & GTK+ 2.22.1:

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'destroy'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'delete_event'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'destroy'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'button2clicked'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'hello'

The buttons have no effect.
gtkbuilder.f90 is not affected by this problem.

[pfossati]

I tested tonight the gtk3 branch with GTK+ 3.0.5 on MacOS X 10.6.7, and gtkbuilder had exactly the same behaviour (i.e. hanging at launch with the same messages).

[bonanza]

The first Mac message seems to tell us that GTK is not able to assign the value NULL to the Fortran type(c_ptr) variable "error". The second message is imho only a subsequent error to the first one. I have no really idea whats wrong here. Maybe the Fortran pointer variable have to be initialized with some target address before?

The Windows messages tell us that GModule is not able to find the symbols for the signal handlers. I had similar problems under Linux with GTK 2.22 which disappeared with GTK 2.24 / Gmodule 2.28. It will be good to test it under Windows with GTK 2.24 or even GTK 3.0.

[vmagnin]

It seems the latest binaries for Windows are only 2.22.1:
http://www.gtk.org/download-windows.html
And there is not yet binaries for GTK+ 3.0. Wait and see...

P.s. James, I have successfully tested your nice hl_choosers.f90 example (ubuntu 11.04, 32 bits, GTK+ 2.24.4), and also hl_dialog.f90. (They just lack the GNU GPL 3 header).

[vmagnin]

I identified a minor problem in gtkbuilder.f90 and gtkbuilder2.f90: when I click on the cross to quit the window instead of using the exit button, the destroy signal is not called. The window disappears but the application is still running.
(Ubuntu 11.04, 32&64 bits)

[bonanza]

This seems to be a general problem with gtkbuilder. The window should have two signal connections (destroy and delete_event). But only one of these (delete_event) is connected, which is the second one in gtkbuilder.glade. However, if the respective lines in gtkbuilder.glade are written in reverse order the result is identical.

[vmagnin]

I have installed Fedora 15 Beta on a 32 bits PC. I think it is the first distribution coming natively with GNOME 3 (GTK+ 3.0.9) and gfortran 4.6.0. The gtk3 branch compiles perfectly. All the examples seems to work without problem, except gtkbuilder.f90 and gtkbuilder2.f90 which just display in the console exactly the same messages than on Paul's Mac OS X. (This was not observed in Ubuntu 11.04)

As expected, when running menu.f90, hl_menu.f90 and notebooks.f90, the "undefined symbol: menu_proxy_module_load" message does not appear anymore, GTK+ 3.0 being fully integrated in the GNOME 3 desktop of Fedora 15.

[vmagnin]

gtkbuilder2.f90 under Windows 7 & GTK+ 2.24.0, Glib 2.28.1, same problem as in my April 18 post:

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'destroy'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'delete_event'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'destroy'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'button2clicked'

(gtkbuilder2.exe:1972): Gtk-WARNING **: Could not find signal handler 'hello'

[bonanza]

I looks like that G_MODULE_EXPORT have to be used to get this working under Windows (and also MacOSX?):
http://tadeboro.blogspot.com/2009/09/glade3-tutorial-6-signals.html
http://developer.gnome.org/glib/unstable/glib-Dynamic-Loading-of-Modules.html#G-MODULE-EXPORT:CAPS
Any ideas how to use G_MODULE_EXPORT with Fortran?

[vmagnin]

G_MODULE_EXPORT macro is defined in /usr/include/glib-2.0/gmodule.h
I don't know how to deal with __declspec(dllexport) which seems to be a compiler directive.

/* exporting and importing functions, this is special cased
 * to feature Windows dll stubs.
 */
#define G_MODULE_IMPORT     extern
#ifdef G_PLATFORM_WIN32
#  define   G_MODULE_EXPORT     __declspec(dllexport)
#else /* !G_PLATFORM_WIN32 */
#  define   G_MODULE_EXPORT
#endif /* !G_PLATFORM_WIN32 */

[bonanza]

Did anyone tried to compile gtkbuilder2.f90 under Windows 64bit? It should work there, since the calling convention changed during changeover to 64bit Windows systems.
However, on 32bit Windows systems it should be possible to fix that using compiler directives !GCC$ ATTRIBUTES.
See:
http://gcc.gnu.org/onlinedocs/gfortran/GNU-Fortran-Compiler-Directives.html
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34112
http://gcc.gnu.org/viewcvs/trunk/gcc/testsuite/gfortran.dg/compiler-directive_1.f90?view=markup

[bonanza]

Now I also got the "assertion `error == NULL || *error == NULL' failed" error using gfortran 4.6.1 20110513, gtk+ 3.0.8 and gmodule 2.28.6 under Linux 64bit.
I was able to resolve that using

type(c_ptr) :: error = c_null_ptr

as initialization expression for "error" which is used in gtk_builder_add_from_file.

[bonanza]

Can anybody try that also under Windows and MacOSX?

[vmagnin]

Good ! gtkbuilder.f90 and gtkbuilder2.f90 are now working under Windows 7 - 32bits & gfortran 4.6.0. Curriously, I first obtained an "internal compiler error: segmentation fault", and I was obliged to write the initialization on two lines:

type(c_ptr) :: error

error = c_null_ptr

Although it is a compiler bug, it would thus be better to commit it with the two lines version.

[bonanza]

It is now committed in all branches (two lines version).
I think, we can close the issue.