ModalWindow.swift

public class ModalWindow : UIView{
    var overlayWindow:UIView?
    var infoStackWindow:UIStackView?
    var titleLabel:UILabel?
    var subTitleLabel:UILabel?
    
    func initialize(){
        backgroundColor = UIColor.blueColor()
        alpha = 0.5
        
        overlayWindow = UIView(frame: bounds)
        overlayWindow!.backgroundColor = UIColor.greenColor()
        overlayWindow!.translatesAutoresizingMaskIntoConstraints = false
        
        createInformationStackView()
        overlayWindow!.addSubview(infoStackWindow!)
        addSubview(overlayWindow!)
        addViewConstraints()
    }
    
    func createInformationStackView(){
        infoStackWindow = UIStackView()
        infoStackWindow!.axis = .Vertical
        infoStackWindow!.alignment = .Center
        infoStackWindow!.distribution = .Fill
        infoStackWindow!.translatesAutoresizingMaskIntoConstraints = false
        
        createTitle()
        createSubtitle()
        
        infoStackWindow!.addArrangedSubview(titleLabel!)
        infoStackWindow!.addArrangedSubview(subTitleLabel!)
    }
    
    func createTitle(){
        titleLabel = UILabel(frame: CGRectZero)
        titleLabel!.text = "My Title"
        titleLabel!.textAlignment = .Center
    }
    func createSubtitle(){
        subTitleLabel = UILabel(frame: CGRectZero)
        subTitleLabel!.text = "Test Subtitle"
        subTitleLabel!.textAlignment = .Center
    }
    
    func addViewConstraints(){
        autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        overlayWindow?.widthAnchor.constraintEqualToAnchor(widthAnchor).active = true
        overlayWindow!.heightAnchor.constraintEqualToAnchor(heightAnchor).active = true
        
        let xCenterConstraint = NSLayoutConstraint(item: infoStackWindow!, attribute: .CenterX, relatedBy: .Equal, toItem: infoStackWindow!.superview, attribute: .CenterX, multiplier: 1, constant: 0)
        overlayWindow!.addConstraint(xCenterConstraint)
        
        let yCenterConstraint = NSLayoutConstraint(item: infoStackWindow!, attribute: .CenterY, relatedBy: .Equal, toItem: infoStackWindow!.superview, attribute: .CenterY, multiplier: 1, constant: 0)
        overlayWindow!.addConstraint(yCenterConstraint)
    }
    
    override public func layoutSubviews() {
        super.layoutSubviews()
        print("Overlay Bounds: \(overlayWindow!.bounds)")
        print("Overlay Frame: \(overlayWindow!.frame)")
        print("Stack Bounds: \(infoStackWindow!.bounds)")
        print("Stack Frame:\(infoStackWindow!.frame)")
    }
    
    required public override init(frame: CGRect) {
        super.init(frame: frame)
        initialize()
    }
    
    public required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}