function GetItemInteraction(pX, pY: integer): TItemInteractionType; override;
end;
function TClickableLargeButtonedItem.GetItemInteraction(pX,
pY: integer): TItemInteractionType;
begin
Result := itNone;
if IsButtonAtXY(pX, pY) and ButtonEnabled then
result := itButton
else if IsStatusAtXY(pX, pY) then
result := itStatus
else if IsItemAtXY(pX, pY) then
result := itDefault;
end;
in the register call you need to call RegisterPolyItem(TClickableLargeButtonedItem) to make sure it is visible in the designtime editor. The OnItemClick should then work when clicking on a part that is not the button.
Creating a custom item is also explained in the manual.