Get the GdkScreen from the toplevel window associated with
this widget. This function can only be called after the widget
has been added to a widget hierarchy with a GtkWindow
at the top.
GdkScreen] the GdkScreen for the toplevel for this widget. [ transfer none ]
Details
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.
Since 2.2
