Sets the widget that should be set as default widget while the popover is shown (see gtk.window.Window.setDefault). #GtkPopover remembers the previous default widget and reestablishes it when the popover is dismissed.
the new default widget, or null
Sets the widget that should be set as default widget while the popover is shown (see gtk.window.Window.setDefault). #GtkPopover remembers the previous default widget and reestablishes it when the popover is dismissed.