Writing a Platform and GUI Toolkit Independent OpenGL Class

#include <gtk/gtk.h>


void on_new1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_open1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_save1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_save_as1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_quit1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_cut1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_copy1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_paste1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_delete1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_about1_activate (GtkMenuItem * menuitem, gpointer user_data);

void on_drawingarea1_realize (GtkWidget * widget, gpointer user_data);

gboolean
on_drawingarea1_configure_event (GtkWidget * widget,
				 GdkEventConfigure * event,
				 gpointer user_data);

gboolean
on_drawingarea1_expose_event (GtkWidget * widget,
			      GdkEventExpose * event, gpointer user_data);

void on_MainWindow_realize (GtkWidget * widget, gpointer user_data);