GtkButton, enter-notify signal, and GdkWindow

[Brian Tietz <sdbtietz yahoo com>]

I am creating two widget subclasses, one which is a subclass of GtkContainer and one which is a subclass of 
GtkButton.  Both need to receive the enter-notify signal.  I can successfully obtain the enter-notify signal 
fot GtkButton in my_button_subclass_init:

    g_gtk_button_mouse_enter_notify_event = widget_class->enter_notify_event;
    widget_class->enter_notify_event = my_button_subclass_enter_notify_event;

That function does get called, I do my thing, and then call the GtkButton class version.  When I try to do 
the same thing for my GtkContainer subclass though, it doesn't happen.  I more or less understand this: my 
GtkContainer subclass is GTK_NO_WINDOW, and according to the Gtk docs I need to put it inside of a 
GtkEventBox.  Fair enough.  But I am studying gtkbutton.c so see how to do this right and to copy its 
methodology, and it isn't creating GtkEventBox.  I found a clue in gtk_button_realize: it's calling 
gdk_window_new, so it seems that GtkButton has its own GdkWindow, which would explain why it received 
enter-notify events.  Fair enough.  Here's the weird part though.  I found that GtkButton has the 
GTK_NO_WINDOW flag set!  Any help in understanding these behaviors and observations would be appreciated.