Painting order in gtk2 vs gtk1.2

[Pierre Habraken <Pierre Habraken imag fr>]

Hello,

I am a newbie to gtk based app. development.
I am a teacher and have to migrate an educational program from gtk1.2 to 
gtk2.

The main window of this program contains a background image with several 
buttons for triggering miscellaneous actions.
These buttons must reside at fixed locations. So, everything displayed 
in the main window is contained in a GtkFixed widget, which one belongs 
to the main window.

I am faced to the following issue:
- with gtk1.2, everything works fine.
- with gtk2, buttons are hidden "behind" the background image: they are
  not visible but if one click at the location where a button resides,
  the corresponding action is triggered.

My question is thus: how to force buttons to be painted after the 
background image has been painted ?

I join a small program which behaves as explained above.
When compiled with options CFLAGS=-Wall -Werror `gtk-config --cflags` 
and LDFLAGS=`gtk-config --libs` the button is displayed upon the 
background image.
When compiled with options CFLAGS=-Wall -Werror `pkg-config --cflags 
gtk+-2.0` and LDFLAGS=`pkg-config --libs gtk+-2.0` the button is hidden 
(though it reacts if one click to the right place).

Thanks a lot in advance for any help.

Pierre
--
Pierre HABRAKEN - mailto:Pierre Habraken imag fr
Tél: 04 76 63 59 94 - Fax: 04 76 51 47 93

#include <gtk/gtk.h>
#include <stdio.h>

#include "image.xpm"

GtkWindow *mainwin;
GtkButton *button;
GtkDrawingArea *drawing_area;
GtkFixed *fixed;
GdkPixmap *image;
   
gboolean realize_event(GtkWidget *widget, gpointer user_data) {
   GdkBitmap *mask;
   GtkStyle *style;

   style = gtk_widget_get_style(GTK_WIDGET(drawing_area));
   image = gdk_pixmap_create_from_xpm_d(
                                       GTK_WIDGET(drawing_area)->window,
                                       &mask,
                                       &style->bg[GTK_STATE_NORMAL],
                                       (gchar **)image_xpm);
   gdk_window_set_back_pixmap(GTK_WIDGET(drawing_area)->window,
                              image, FALSE);
   printf("realize_event\n");
   return TRUE;
}

void cb_button(GtkWidget *w, gpointer func_data) {
   printf("button\n");
}

int main(int argc, char **argv) {
   gtk_init (&argc, &argv);

   mainwin=GTK_WINDOW(gtk_window_new(GTK_WINDOW_TOPLEVEL));

   fixed=GTK_FIXED(gtk_fixed_new());
   gtk_widget_show(GTK_WIDGET(fixed));

   drawing_area=GTK_DRAWING_AREA(gtk_drawing_area_new());
   gtk_drawing_area_size(GTK_DRAWING_AREA(drawing_area), 910, 600);
   gtk_signal_connect(GTK_OBJECT(drawing_area), "realize",
                      GTK_SIGNAL_FUNC(realize_event), NULL);
   gtk_fixed_put(fixed,GTK_WIDGET(drawing_area),0,0);

   button=GTK_BUTTON(gtk_button_new_with_label("Button"));
   gtk_widget_show(GTK_WIDGET(button));
   gtk_signal_connect(GTK_OBJECT(button), "released",
                      GTK_SIGNAL_FUNC(cb_button), NULL);
   gtk_fixed_put(fixed,GTK_WIDGET(button),680, 264);

   gtk_container_add(GTK_CONTAINER(mainwin),GTK_WIDGET(fixed));

   gtk_widget_show_all(GTK_WIDGET(mainwin));
   gtk_widget_realize(GTK_WIDGET(mainwin));
   gtk_main();

   return 0;
}

Attachment: image.xpm.gz
Description: GNU Zip compressed data