Can't retrieve actual GdkWindow for a Gtk::Widget

["Timothy M. Shead" <tshead k-3d com>]

I am working on some tutorial-playback functionality for a gtkmm-based 
application, K-3D (http://k3d.sourceforge.net).  To this end, I would 
like to synthesize Gdk events and insert them into the main event loop. 
 This would not be difficult, except that I cannot obtain the actual 
GdkWindow for a given widget.  If you run the attached example, press 
the button, and view the console output, you will see that the GdkWindow 
in the GdkEvent object is not the same as the window returned by 
button.get_window()->gobj().  In fact, the latter returns the *parent* 
of the GdkEvent window.  I need to obtain the actual widget window so I 
can generate corresponding events for it.  Could anyone comment on this 
behavior?

Many thanks,
Tim Shead

#include <gtkmm.h>
#include <iostream>

void on_gdk_event(GdkEvent* Event, gpointer Data)
{
	if(Event->type == GDK_BUTTON_PRESS)
	{
		std::cerr << "gdk event window:            " << Event->any.window << std::endl;
		std::cerr << "gdk event window parent:     " << gdk_window_get_parent(Event->any.window) << std::endl;
	}

	gtk_main_do_event(Event);
}

struct window :
	public Gtk::Window
{
	window() :
		button("press me")
	{
		resize(200, 30);
		add(button);
		button.signal_clicked().connect(sigc::mem_fun(*this, &window::on_button_click));
		set_position(Gtk::WIN_POS_CENTER);
		show_all();
	}

	void on_button_click()
	{
		std::cerr << "gtkmm widget window:         " << button.get_window()->gobj() << std::endl;
		Gtk::Main::quit();
	}
	
	Gtk::Button button;
};

void on_button_click()
{
	std::cerr << "button click" << std::endl;
}

int main(int argc, char *argv[])
{
	Gtk::Main kit(argc, argv);

	gdk_event_handler_set(on_gdk_event, NULL, NULL);

	window w;
	Gtk::Main::run(w);

	return 0;
}