Failing to stroke() the UIBezierPath - ios

Question

I wish to create a perfectly rounded rect (Circle) and paint it on the screen. I have tested my code in playground, and it successfully paints the UIBezierPath. It doesn't, however, successfully paint it in the iOS simulator. Here's the code I've been working on:
class Circles {
//Defining the rounded rect (Circle)
func roundRect(radius: CGFloat, angle: CGFloat) -> UIBezierPath {
//Creating the rounded the rectangle (Circle)
var roundedRect = UIBezierPath()
roundedRect.addArcWithCenter(CGPointZero, radius: radius,
startAngle: 0, endAngle: angle ,
clockwise: true)
return roundedRect
}
//Drawing the Bezier Path (Circle)
func drawRect(rect: UIBezierPath){
rect.moveToPoint(self.point)
UIColor.blackColor().setStroke()
rect.stroke()
}
//Giving the rounded rect (Circle) it's position
var point = CGPointMake(500, 500)
}
//Giving the rounded rect (Circle) it's size
var newRect = Circles().roundRect(200.0, angle: 7)
//Drawing the rounded rect (Circle)
Circles().drawRect(newRect)
I have seen some other posts with similar problems from a few years back, however they were in Objective-C, I tried translating but it was not of any use. I've also tried several other methods of painting the path on the screen but, again sadly, it was of no use. I tested it to make sure the functions are working with println statements, the issue is I don't know why the stroke is not activating. Thanks for reading, -Zach.
Here's the updated version using what Mike said:
class CircleView: UIView {
override func drawRect(rect: CGRect) {
// Creating the rectangle's size
var newRect = Circles().roundRect(200.0, angle: 7)
//Drawing the rectangle
Circles().drawRect(newRect)
}
//Holding all to do with the circle
class Circles {
//Defining the rounded rect (Circle)
func roundRect(radius: CGFloat, angle: CGFloat) -> UIBezierPath {
//Creating the rounded rect (Circle)
var roundedRect = UIBezierPath()
roundedRect.addArcWithCenter(CGPointZero, radius: radius,
startAngle: 0, endAngle: angle ,
clockwise: true)
return roundedRect
}
//Drawing the Bezier Path (Circle)
func drawRect(rect: UIBezierPath){
rect.moveToPoint(self.point)
UIColor.blackColor().setStroke()
UIColor.blackColor().setFill()
rect.stroke()
rect.fill()
}
//Giving the rounded rect (Circle) it's position
var point = CGPointMake(500, 500)
}
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
//Generating the background
self.view.backgroundColor = UIColor(patternImage: UIImage(named: "normalpaper.jpg"))
let circleView = CircleView(frame: self.view.bounds)
self.view.addSubview(circleView)
}

Answer 1

As you mentioned in the comments, you're calling drawRect from a UIViewController's viewDidLoad function. You don't have a valid drawing context there, so that's not going to work.
The easiest way to make this work is to create a UIView subclass with its own drawRect function which calls Circle().drawRect(...) and add that as a subview of your UIViewController's view.
Here's an example of this:
Note: I've made the custom view transparent by setting circleView.opaque = false so that the background you mentioned in the comments shows through.
class CircleView: UIView {
override func drawRect(rect: CGRect) {
// I just copied this directly from the original question
var newRect = Circles().roundRect(200.0, angle: 7)
Circles().drawRect(newRect)
}
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Create a new CircleView that's the same size of this
// view controller's bounds and add it to the view hierarchy
let circleView = CircleView(frame: self.view.bounds)
circleView.opaque = false
self.view.addSubview(circleView)
}
}
Note: If you're going to be doing custom drawing, I highly recommend you read Drawing and Printing Guide for iOS. It'll teach you all the basics you need to make it work.