HitTest

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    if (self.clipsToBounds || self.hidden || (self.alpha == 0.f)) {
        return nil;
    }
    UIView *view = [super hitTest:point withEvent:event];
    if (view) {
        return view;
    }
    for (UIView *subView in self.subviews.reverseObjectEnumerator) {
        CGPoint subPoint = [subView convertPoint:point fromView:self];
        view = [subView hitTest:subPoint withEvent:event];
        if (view) {
            return view;
        }
    }
    return nil;
}