Drawing an NSBezierPath Shape with NSView Subclass - swift

Question

I'm trying to draw a shape that is created with NSBezierPath on an NSView canvas. I've created a subclass of NSView.
// NSView //
import Cocoa
class DisplayView: NSView {
var path: NSBezierPath
var fillColor: NSColor
var strokeColor: NSColor
var weight: CGFloat
init(frame: CGRect, path: NSBezierPath, fillColor: NSColor, strokeColor: NSColor, weight: CGFloat){
self.path = path
self.fillColor = fillColor
self.strokeColor = strokeColor
self.weight = weight
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func draw(_ dirtyRect: NSRect) {
path.lineWidth = weight
fillColor.set()
path.fill()
strokeColor.set()
path.stroke()
}
}
// NSViewController //
import Cocoa
class ViewController: NSViewController {
// MARK: - IBOutlet
#IBOutlet weak var canvasView: NSView!
override func viewDidLoad() {
super.viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
let path = Shapes.circle(maxSize: 100) // a path from a separate class
let rect = CGRect(x: 20, y: 20, width: 200, height: 200)
let pathView = DisplayView(frame: rect, path: path, fillColor: NSColor.green, strokeColor: NSColor.white, weight: 6.0)
canvasView.addSubview(pathView)
}
}
And I get the following result. How come the edges are broken by half the line weight on two sides? The path object is only a size of 100 pts x 100 pts. Thanks.
UPDATE
The following is the code for making a path object.
class Shapes {
static func circle(maxSize: CGFloat) -> NSBezierPath {
let oval = NSBezierPath.init(ovalIn: CGRect(x: 0.0 * maxSize, y: 0.0 * maxSize, width: 1.0 * maxSize, height: 1.0 * maxSize))
oval.close()
return oval
}
}

Answer 1

You have created your bezier path with an origin of 0,0. As a result, the thicker border gets clipped by the view it is rendered in (your DisplayView class).
You need to create your path so the origin is (weight / 2 + 1) instead of 0.
Or you can apply a translate transform to the graphics context and shift the origin by (weight / 2 + 1.
override func draw(_ dirtyRect: NSRect) {
let ctx = NSGraphicsContext.current!.cgContext
ctx.saveGState()
let offset = weight / 2 + 1
ctx.translateBy(x: offset, y: offset)
path.lineWidth = weight
fillColor.set()
path.fill()
strokeColor.set()
path.stroke()
ctx.restoreGState()
}