gtkFixed

#include <gtk/gtk.h>

int main(int argc, char *argv[]) {

  GtkWidget *window;
  GtkWidget *fixed;

  GtkWidget *btn;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window), "GtkFixed");
  gtk_window_set_default_size(GTK_WINDOW(window), 400, 300);
  gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);

  fixed = gtk_fixed_new();
  gtk_container_add(GTK_CONTAINER(window), fixed);

  btn = gtk_button_new_with_label("Button");
  gtk_fixed_put(GTK_FIXED(fixed), btn, 160, 130);
  gtk_widget_set_size_request(btn, 80, 30);

  g_signal_connect(G_OBJECT(window), "destroy",
      G_CALLBACK(gtk_main_quit), NULL);

  gtk_widget_show_all(window);

  gtk_main();

  return 0;
}