gtk-widget-screen (widget)

widget -- a gtk-widget object

The gdk-screen object for the toplevel for the widget.

Get the screen from the toplevel window associated with the widget. This function can only be called after the widget has been added to a widget hierarchy with a gtk-window widget at the top.

In general, you should only create screen specific resources when a widget has been realized, and you should free those resources when the widget is unrealized.