Gtk.Widget:has-tooltip
"has-tooltip" Boolean : Read / Write
Enables or disables the emission of Gtk.Widget::query-tooltip on @widget. A value of true indicates that @widget can have a tooltip, in this case the widget will be queried using Gtk.Widget::query-tooltip to determine whether it will provide a tooltip or not.
Note that setting this property to true for the first time will change the event masks of the GdkWindows of this widget to include leave-notify and motion-notify events. This cannot and will not be undone when the property is set to false again.
Since 2.12