Gtk.Widget::focus-in-event

function callback(widget, event:Gdk.EventFocus, ):Boolean;

The ::focus-in-event signal will be emitted when the keyboard focus enters the @widget's window.

To receive this signal, the Gdk.Window associated to the widget needs to enable the #GDK_FOCUS_CHANGE_MASK mask.

widget: instance of Gtk.Widget that is emitting the signal
event: the Gdk.EventFocus which triggered this signal.
Returns: true to stop other handlers from being invoked for the event. false to propagate the event further.