is_focus
Description:
true if focus is in the controllers widget itself, as opposed to in a descendent widget.
See also [property@Gtk.EventControllerFocus:contains-focus].
When handling focus events, this property is updated before [signal@Gtk.EventControllerFocus:GtkEventControllerFocus:enter
] or [
signal@Gtk.EventControllerFocus:GtkEventControllerFocus:leave
] are emitted.