Create a bezier path with rounded corners based on a radius and existing frame. Most useful if you want to add in other shapes into the path while still maintaining rounded corners (for example, an arrow).

gistfile1.m

- (UIBezierPath *)roundedPathFromRect(CGRect)f
{
  UIBezierPath *path = [[UIBezierPath alloc] init];
  NSInteger radius = 4.0;

  // Draw the path
  [path moveToPoint:CGPointMake(radius, 0)];
  [path addLineToPoint:CGPointMake(f.size.width - radius, 0)];
  [path addArcWithCenter:CGPointMake(f.size.width - radius, radius)
                  radius:radius
              startAngle:- (M_PI / 2)
                endAngle:0
               clockwise:YES];
  [path addLineToPoint:CGPointMake(f.size.width, f.size.height - radius)];
  [path addArcWithCenter:CGPointMake(f.size.width - radius, f.size.height - radius)
                  radius:radius
              startAngle:0
                endAngle:- ((M_PI * 3) / 2)
               clockwise:YES];
  [path addLineToPoint:CGPointMake(radius, f.size.height)];
  [path addArcWithCenter:CGPointMake(radius, f.size.height - radius)
                  radius:radius
              startAngle:- ((M_PI * 3) / 2)
                endAngle:- M_PI
               clockwise:YES];
  [path addLineToPoint:CGPointMake(0, radius)];
  [path addArcWithCenter:CGPointMake(radius, radius)
                  radius:radius
              startAngle:- M_PI
                endAngle:- (M_PI / 2)
               clockwise:YES];

  return path;
}