flutter info button
//_tooltipKey is defined as final _tooltipKey = GlobalKey();
Tooltip(
key: _tooltipKey,
message: S.of(context).dishSpicinessRatingExplanation,
textStyle: regularTextStyle.copyWith(color: Colors.white),
preferBelow: false,
child: IconButton(
icon: FaIcon(FontAwesomeIcons.infoCircle, color: Colors.black45),
onPressed: (){
final dynamic tooltip = _tooltipKey.currentState;
tooltip.ensureTooltipVisible();
},
)
)