three uniformly spaced labels

uniformelyspacedLabels.swift

//
//  MyView.swift
//  TestPopover
//
//  Created by Arash Kashi on 1/2/17.
//  Copyright © 2017 Arash Kashi. All rights reserved.
//

import Foundation
import UIKit



@IBDesignable


class MyView: UIView {
    
    lazy var leftLabel: UILabel = {
        
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.textColor = .black
        label.text = "leftleftleftleft"
        return label
    }()
    
    lazy var middleLabel: UILabel = {
        
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.textColor = .black
        label.text = "middle"
        return label
    }()
    
    lazy var rightLabel: UILabel = {
        
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        label.textColor = .black
        label.text = "right"
        return label
    }()
    
    private var leftEdgeGuide: UILayoutGuide    = UILayoutGuide()
    private var leftMiddleGuide: UILayoutGuide  = UILayoutGuide()
    private var rightMiddleGuide: UILayoutGuide = UILayoutGuide()
    private var rightEdgeGuide: UILayoutGuide   = UILayoutGuide()

    override func layoutSubviews() {
        
        super.layoutSubviews()
        
        addSubview(leftLabel)
        addSubview(middleLabel)
        addSubview(rightLabel)
        
        [leftEdgeGuide,
         leftMiddleGuide,
         rightMiddleGuide,
         rightEdgeGuide].forEach { self.addLayoutGuide($0) }
        
        leftEdgeGuide.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        leftEdgeGuide.trailingAnchor.constraint(equalTo: leftLabel.leadingAnchor).isActive = true
        
        leftLabel.trailingAnchor.constraint(equalTo: leftMiddleGuide.leadingAnchor).isActive = true
        leftMiddleGuide.trailingAnchor.constraint(equalTo: middleLabel.leadingAnchor).isActive = true
        
        middleLabel.trailingAnchor.constraint(equalTo: rightMiddleGuide.leadingAnchor).isActive = true
        rightMiddleGuide.trailingAnchor.constraint(equalTo: rightLabel.leadingAnchor).isActive = true
        
        rightLabel.trailingAnchor.constraint(equalTo: rightEdgeGuide.leadingAnchor).isActive = true
        rightEdgeGuide.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
        
        leftEdgeGuide.widthAnchor.constraint(equalTo: leftMiddleGuide.widthAnchor).isActive = true
        
        leftMiddleGuide.widthAnchor.constraint(equalTo: rightMiddleGuide.widthAnchor).isActive = true
        rightMiddleGuide.widthAnchor.constraint(equalTo: rightEdgeGuide.widthAnchor).isActive = true
        
        leftLabel.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
        rightLabel.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
        middleLabel.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
        
        self.setNeedsLayout()
    }
}