I had tried check inside cell backgroundView, but for both styles (UITableViewStylePlain, UITableViewStyleGrouped) were equal to NOT nil. There is whether any way to get UITableViewStyle from inside UITableViewCell?
SOLVED: I just added to cell constructor a variable of type UITableViewStyle and set it when created
Ideally, your cell shouldn't care what the style is.
But if you must know, your best bet is to do something like this:
UIView *tv = self;
while (tv && ![tv isKindOfClass:[UITableView class]]) tv = tv.superview;
UITableViewStyle style = [(UITableView *)tv style];