Вместо переопределения drawIconWithFrame: метод TIconAndTextCell, вы должны переопределить drawIconWithFrame: метод TNodeIconAndNameCell.
Class finder_class = [objc_getClass("TNodeIconAndNameCell") class];
class_addMethod(finder_class, @selector(FT_drawIconWithFrame:),
class_getMethodImplementation(self_class, @selector(FT_drawIconWithFrame:)),"v@:{CGRect={CGPoint=dd}{CGSize=dd}}");
old = class_getInstanceMethod(finder_class, @selector(drawIconWithFrame:));
new = class_getInstanceMethod(finder_class, @selector(FT_drawIconWithFrame:));
method_exchangeImplementations(old, new);
И тогда вы можете сделать это:
NSLog(@"%@", [[[NSClassFromString(@"FINode") nodeWithFENode:[self node]] fullPath] lastPathComponent]);