Passing A Variable (Color) To a NSView?

Question

I'm hoping someone can help me figure out why I'm having such a hard time passing a variable to my NSView. Essentially, I am trying to set a variable ( myColor ) to set the color of a circle I am drawing. The code appears like so;

import Cocoa

class Circle: NSView {

var myColor:NSColor? = NSColor.greenColor()

lazy var innerRing: CAShapeLayer = {
    let innerRing = CAShapeLayer()
    let circleRadius: CGFloat = 20.0
    innerRing.frame = self.bounds

    var circleFrame = CGRect(x: 0, y: 0, width: circleRadius, height: circleRadius)
    circleFrame.origin.x = CGRectGetMidX(self.bounds) - CGRectGetMidX(circleFrame)
    circleFrame.origin.y = CGRectGetMidY(self.bounds) - CGRectGetMidY(circleFrame)

    innerRing.path = CGPathCreateWithEllipseInRect(circleFrame, nil)
    innerRing.lineWidth = 3.0
    innerRing.strokeStart = 0.0
    innerRing.strokeEnd = 0.75
    innerRing.fillColor = NSColor.clearColor().CGColor
    innerRing.strokeColor = myColor.CGColor

//THIS LINE THROWS THE ERROR

    return innerRing
    }()

override func awakeFromNib() {
    super.awakeFromNib()

    wantsLayer = true
    layer = CALayer()
    layer?.addSublayer(innerRing)
}
}

I keep receiving the error Instance member 'myColor' cannot be used on type 'Circle' . If I set my strokeColor to be something simple, like NSColor.blueColor().CGColor, it compiles without issue. But I've never had such issue setting a variable before, and I'm not sure what I'm doing wrong.

EDIT: Updating with solution

import Cocoa

class Circle: NSView {

lazy var innerRing: CAShapeLayer = {

    let innerRing = CAShapeLayer()
    let circleRadius: CGFloat = 20.0
    innerRing.frame = self.bounds

    var circleFrame = CGRect(x: 0, y: 0, width: circleRadius, height: circleRadius)
    circleFrame.origin.x = CGRectGetMidX(self.bounds) - CGRectGetMidX(circleFrame)
    circleFrame.origin.y = CGRectGetMidY(self.bounds) - CGRectGetMidY(circleFrame)

    innerRing.path = CGPathCreateWithEllipseInRect(circleFrame, nil)
    innerRing.lineWidth = 2.0
    innerRing.strokeStart = 0.0
    innerRing.strokeEnd = 0.75
    innerRing.fillColor = NSColor.greenColor().CGColor
    innerRing.strokeColor = NSColor.blackColor().CGColor
    return innerRing
    }()

override func awakeFromNib() {
    super.awakeFromNib()

    wantsLayer = true
    layer = CALayer()
    layer?.addSublayer(innerRing)
    }

}

I am then calling this from another View Controller my using cirleView.innerRing.strokeColor = NSColor.redColor().CGColor , eliminating the need for a separate myColor variable altogether.

Answer 1

Your myColor is typed as an Optional ( NSColor? ). You therefore have to unwrap it before you can get its CGColor property. Also, you're in an anonymous function here, so you must refer explicitly to self in order to access your property. Thus, this will fix the problem:

innerRing.strokeColor = self.myColor!.CGColor

Or, even better, don't type myColor as an Optional; just make it an NSColor. You can do this because you are giving it a default value right there in the declaration. You then won't have anything to unwrap and the exclamation mark won't be needed.