UISegmentedControl tintColor gradient - ios

Question

I'm trying to set the foreground/tintColor of a UISegmentedControl to a horizontal gradient. I want the gradient to extend across the control and appropriately adjust when each segment is clicked. See image below:
I've tried setting the tintColor using the stackoverflow solution found here, but using colorWithPattern doesn't seem to work when I change it to be horizontal:
Here's what I'm using now:
UIView* test2 = [[UIView alloc] initWithFrame:CGRectMake(10, 60, 200, 25)];
test2.backgroundColor = [self gradientFromColor:[UIColor redColor] toColor:[UIColor greenColor] withWidth:test2.frame.size.width];
[self.view addSubview:test2];
UISegmentedControl *test = [[UISegmentedControl alloc] initWithItems:#[#"one", #"two"]];
test.frame = CGRectMake(10, 100, 200, 25);
test.tintColor = [self gradientFromColor:[UIColor redColor] toColor:[UIColor greenColor] withWidth:test.frame.size.width];
[self.view addSubview:test];
...
- (UIColor*) gradientFromColor:(UIColor*)c1 toColor:(UIColor*)c2 withWidth:(int)width{
CGSize size = CGSizeMake(width, 1);
UIGraphicsBeginImageContextWithOptions(size, NO, 1);
CGContextRef context = UIGraphicsGetCurrentContext();
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
NSArray* colors = [NSArray arrayWithObjects:(id)c1.CGColor, (id)c2.CGColor, nil];
CGGradientRef gradient = CGGradientCreateWithColors(colorspace, (CFArrayRef)colors, NULL);
CGContextDrawLinearGradient(context, gradient, CGPointMake(0, 0), CGPointMake(width, 0), 0);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
CGGradientRelease(gradient);
CGColorSpaceRelease(colorspace);
UIGraphicsEndImageContext();
return [UIColor colorWithPatternImage:image];
}
I'm thinking I need to do some work with masking but I've been having trouble getting it to work.