grabFocus

Causes @widget to have the keyboard focus for the GtkWindow it's inside.

If @widget is not focusable, or its vfunc@Gtk.Widget.grab_focus implementation cannot transfer the focus to a descendant of @widget that is focusable, it will not take focus and false will be returned.

Calling method@Gtk.Widget.grab_focus on an already focused widget is allowed, should not have an effect, and return true.