toggleable property

@override set toggleable (Toggleable popupRef)

Implementation

@override
set toggleable(Toggleable popupRef) {
  // This directive implements both [Toggler] and [PopupSource]. Upon seeing
  // that the source is an instance of [Toggler], the [PopupComponent] on
  // which both the Ink and Paper tooltip components are built registers the
  // [PopupRef] as a [Toggleable].
  _popupRef = popupRef;
}