gistfile1.swift

import Cocoa

struct Constraint {
    typealias T = (attribute: CAConstraintAttribute, relativeTo:String, relatedAttribute: CAConstraintAttribute, offset: CGFloat)
    let data: T

    func create() -> CAConstraint {
        let newConstraint: AnyObject! = CAConstraint.constraintWithAttribute(data.attribute, relativeTo: data.relativeTo, attribute: data.relatedAttribute, offset: data.offset)
        return newConstraint as CAConstraint
    }
    static func process(list:[T], _ layer:CALayer) {
        for each in list {
            let c = Constraint(data:each).create()
            layer.addConstraint(c)
        }
    }
}

var r = CGRectMake(0,0,300,300)
var view = NSView(frame:r)
var layer = CALayer()
layer.layoutManager = CAConstraintLayoutManager()

//MARK:- You can now create a layer and define constraints in a succinct manner

internal class BaseCALayer {
    private var layer: CALayer
    private var _constraint:[Constraint.T]?
    private var constraint:[Constraint.T] {
        set(newValue)
        {
            Constraint.process(newValue,layer)
        }
        get
        {
            return  _constraint!
        }
    }
    init() {
        layer = CALayer()
    }
}

//MARK:- here's the core idea, use the typed tuple as a container and massage it into a layer

class LayerB: BaseCALayer {
    override init() {
        super.init()
        layer.name = "layerB"
        layer.bounds = CGRectMake(0,0,300,60)
        layer.borderWidth = 2.0
        layer.backgroundColor = NSColor.redColor().CGColor
        constraint = [
            (.Width, "layerA", .Width, 0),
            (.MidX, "layerA", .MidX, 0),
            (.MaxY, "layerA", .MinY, -10),
            (.MinY, "superlayer", .MinY, +10)]
    }
}

class LayerC : BaseCALayer {
    override init() {
        super.init()
        layer.name = "layerC"
        layer.bounds = CGRectMake(0,0,40,40)
        layer.borderWidth = 4.0
        layer.backgroundColor = NSColor.yellowColor().CGColor
        constraint = [
            (.MinX, "layerB", .MaxX, +10),
            (.MaxY, "layerA", .MinY, -10)]
    }
}

//MARK:- etc...
class LayerA: BaseCALayer {
    override init() {
        super.init()
        layer.name = "layerA"
        layer.bounds = CGRectMake(0,0,200,125)
        layer.borderWidth = 2.0
        layer.backgroundColor = NSColor.greenColor().CGColor
        constraint = [
            (.MidY, "superlayer", .MidY, 0),
            ( .MidX, "superlayer", .MidX, 0)]
    }
}

layer.addSublayer(LayerC().layer)
layer.addSublayer(LayerA().layer)
layer.addSublayer(LayerB().layer)
view.layer = layer