[gtkada] Problem writing a librsvg Ada binding

[Damien Carbonne]

Hi,

I'm trying to write a librsvg Ada binding and have a problem with it.
As librsvg depends on glib/gdk, I've used GtkAda for that.
Note: This binding will be available using the same license as GtkAda on 
which it depends.

An extract of what is available on C side in rsvg.h is:

/************************************************************/
// ...
typedef struct _RsvgHandle RsvgHandle;
typedef struct RsvgHandlePrivate RsvgHandlePrivate;
typedef struct _RsvgHandleClass RsvgHandleClass;
typedef struct _RsvgDimensionData RsvgDimensionData;

struct _RsvgHandleClass {
        GObjectClass parent;

        gpointer _abi_padding[15];
};

struct _RsvgHandle {
        GObject parent;

        RsvgHandlePrivate *priv;

        gpointer _abi_padding[15];
};
// ...

void rsvg_init (void);
// ...
/************************************************************/

An extract of what I wrote on Ada side is:

--------------------------------------------------------------
package RSVG is

   -- ...

   type RSVG_Handle_Record is new Glib.Object.GObject_Record with private;
   type RSVG_Handle is access all RSVG_Handle_Record'Class;

   -- ...

   procedure SRVG_New_From_File
     (Handle   : out RSVG_Handle;
      Filename : String;
      Error    : out GError);

   -- ...

private
   -- ...
   type RSVG_Handle_Record is new Glib.Object.GObject_Record with null 
record;
end RSVG;
--------------------------------------------------------------

The implementation of SRVG_New_From_File is:

--------------------------------------------------------------
   procedure SRVG_New_From_File
     (Handle   : out RSVG_Handle;
      Filename : String;
      Error    : out GError)
   is
      function Internal (Filename : System.Address; Error : access 
GError) return System.Address;
      pragma Import (C, Internal, "rsvg_handle_new_from_file");
      C_Filename : constant String := Filename & ASCII.nul;
      Err : aliased GError;
   begin
      Handle := new RSVG_Handle_Record;
      Set_Object (Handle, Internal (C_Filename'Address, Err'Access));
      Error := Err;
   end SRVG_New_From_File;
--------------------------------------------------------------
I wrote this by following what is done for Gtk_New in Gtk.Window.

But when I use all this, it fails and I get these messages:

===============================================================
(process:18095): GLib-GObject-CRITICAL **: gtype.c:2240: initialization 
assertion failed, use IA__g_type_init() prior to this function

(process:18095): GLib-GObject-CRITICAL **: gtype.c:2240: initialization 
assertion failed, use IA__g_type_init() prior to this function

(process:18095): GLib-GObject-CRITICAL **: g_object_new: assertion 
`G_TYPE_IS_OBJECT (object_type)' failed
===============================================================

I have not found any procedure that binds g_type_init in GtkAda.

Any help would be appreciated.

Regards

Damien Carbonne