Question about GtkButton->event_window.

["Tom Liu" <tom liu flextrade com>]

I check the source code of GtkButton, Looks the GtkButton create a GdkWindow called event_window. and  GtkButton->event_window coves the GtkWidget->window. But When expose event comes, they paint the button on the GtkWidget->window. How can the button’s images show up?

 

Why the GtkButton don’t use the GtkWidget->window as it’s own GdkWindow?  

 

 

Thanks.