BackgroundedLabel.swift

//
//  ViewController.swift
//  Test
//
//  Created by Oscar Swanros on 3/3/17.
//  Copyright © 2017 Pacific3. All rights reserved.
//

import UIKit

class BackgroundedLabel: UIView {
    private lazy var internalLabel: UILabel = {
        let l = UILabel()
        l.translatesAutoresizingMaskIntoConstraints = false
        l.lineBreakMode = .byWordWrapping
        l.numberOfLines = 0
        return l
    }()
    
    override var intrinsicContentSize: CGSize {
        return CGSize(width: 20, height: 50)
    }
    
    var text: String
    
    init(text: String) {
        self.text = text
        super.init(frame: .zero)
        
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    private func commonInit() {
        addSubview(internalLabel)
        
        translatesAutoresizingMaskIntoConstraints = false
        
        NSLayoutConstraint.activate(
            [
                internalLabel.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),
                internalLabel.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor),
                internalLabel.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
                internalLabel.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor)
            ]
        )
        
        backgroundColor = .clear
        
        let paragraph = NSMutableParagraphStyle()
        paragraph.lineSpacing = 5
        
        let stringWithAttachment = NSMutableAttributedString()
        
        for word in text.components(separatedBy: " ") {
            let word = image(from: (word as NSString))
            
            let att = NSTextAttachment()
            att.image = word
            
            let space = image(from: " ")
            let sp = NSTextAttachment()
            sp.image = space
            
            stringWithAttachment.append(NSAttributedString(attachment: att))
            stringWithAttachment.append(NSAttributedString(attachment: sp))
        }
        
        stringWithAttachment.addAttribute(NSParagraphStyleAttributeName, value: paragraph, range: NSRange(location: 0, length: stringWithAttachment.string.characters.count))
        
        internalLabel.attributedText = stringWithAttachment
    }
    
    private func image(from word: NSString) -> UIImage {
        let attrs = [
            NSBackgroundColorAttributeName: UIColor.red,
            NSFontAttributeName: UIFont.systemFont(ofSize: 18, weight: UIFontWeightRegular),
            NSForegroundColorAttributeName: UIColor.white
        ]
        
        let size = word.size(attributes: attrs)
        
        let renderer = UIGraphicsImageRenderer(size: size)
        return renderer.image { context in
            UIColor.red.setFill()
            
            word.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height), withAttributes: attrs)
        }
    }
}


class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
       
        let label = BackgroundedLabel(text: "UPGRADE TO SEE WHO'S BEEN LOOKING AT YOUR PROFILE")
        view.addSubview(label)
        
        label.topAnchor.constraint(equalTo: view.layoutMarginsGuide.topAnchor, constant: 50).isActive = true
        label.leadingAnchor.constraint(equalTo: view.layoutMarginsGuide.leadingAnchor).isActive = true
        label.widthAnchor.constraint(equalToConstant: 300).isActive = true
        
    }
}