Gtk.Widget:tooltip-text

"tooltip-text"             String                : Read / Write

Sets the text of tooltip to be the given string.

Also see Gtk.Tooltip.prototype.set_text.

This is a convenience property which will take care of getting the tooltip shown if the given string is not null: Gtk.Widget:has-tooltip will automatically be set to true and there will be taken care of Gtk.Widget::query-tooltip in the default signal handler.

Since 2.12