contains_pointer
Description:
Whether the pointer is in the controllers widget or a descendant.
See also [property@Gtk.EventControllerMotion:is-pointer].
When handling crossing events, this property is updated before [signal@Gtk.EventControllerMotion:GtkEventControllerMotion:enter
],
but after [signal@Gtk.EventControllerMotion:GtkEventControllerMotion:leave
] is emitted.