Testing widget visibility?

["Ian Puleston" <ian underpressuredivers com>]

Hi,

Is there a simple way to test if a widget really is visible (i.e. the user
can actually see it). GTK_WIDGET_VISIBLE returns true if the widget has been
set to show, but that does not mean that it is actually visible - if it is
in a box that is currently hidden then the widget is not visible on the
window.

One option should be to recursively use gtk_widget_get_parent to check the
visibility of each parent up to the top window, but is there a simpler way
to do it?

Ian