Кнопка со скруглениями и картинками, настраиваемая через InterfaceBuilder.

CustomButton.swift

@IBDesignable class CustomButton: UIButton {
    private var leftImageView: UIImageView!
    private var rightImageView: UIImageView!
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setUp()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setUp()
    }
    
    override func awakeFromNib() {
        super.awakeFromNib()
        setUp()
    }
    
    private func setUp() {
        clipsToBounds = true
        leftImageView = UIImageView(image: leftImage?.tintedImage(color ?? tintColor))
        rightImageView = UIImageView(image: rightImage?.tintedImage(color ?? tintColor))
    }
    
    @IBInspectable var borderWidth: CGFloat {
        set { layer.borderWidth = newValue }
        get { return layer.borderWidth }
    }
    
    @IBInspectable var color: UIColor? {
        didSet {
            layer.borderColor = color?.cgColor
            tintColor = color
        }
    }
    
    @IBInspectable var cornerRadius: CGFloat {
        set { layer.cornerRadius = newValue }
        get { return layer.cornerRadius  }
    }
    
    @IBInspectable var leftImage: UIImage? {
        didSet {
            leftImageView.image = leftImage?.tintedImage(color ?? tintColor)
        }
    }
    
    @IBInspectable var rightImage: UIImage? {
        didSet {
            rightImageView.image = rightImage?.tintedImage(color ?? tintColor)
        }
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        addSubview(leftImageView)
        leftImageView.translatesAutoresizingMaskIntoConstraints = false
        
        let leftImageWidth = NSLayoutConstraint(item: leftImageView,
                                       attribute: .width,
                                       relatedBy: .equal,
                                       toItem: nil,
                                       attribute: .notAnAttribute,
                                       multiplier: 1,
                                       constant: 20)
        
        let leftImageHeight = NSLayoutConstraint(item: leftImageView,
                                        attribute: .height,
                                        relatedBy: .equal,
                                        toItem: nil,
                                        attribute: .notAnAttribute,
                                        multiplier: 1,
                                        constant: 20)
        
        leftImageView.addConstraints([leftImageWidth, leftImageHeight])
        
        
        let leftImageRight = NSLayoutConstraint(item: leftImageView,
                                            attribute: .left,
                                            relatedBy: .equal,
                                            toItem: self,
                                            attribute: .left,
                                            multiplier: 1,
                                            constant: 16)
        
        let leftImageCenter = NSLayoutConstraint(item: leftImageView,
                                             attribute: .centerY,
                                             relatedBy: .equal,
                                             toItem: self,
                                             attribute: .centerY,
                                             multiplier: 1,
                                             constant: 0)
        
        addConstraints([leftImageRight, leftImageCenter])
        
        
        
        addSubview(rightImageView)
        rightImageView.translatesAutoresizingMaskIntoConstraints = false
        
        let rightImageWidth = NSLayoutConstraint(item: rightImageView,
                                                attribute: .width,
                                                relatedBy: .equal,
                                                toItem: nil,
                                                attribute: .notAnAttribute,
                                                multiplier: 1,
                                                constant: 20)
        
        let rightImageHeight = NSLayoutConstraint(item: rightImageView,
                                                 attribute: .height,
                                                 relatedBy: .equal,
                                                 toItem: nil,
                                                 attribute: .notAnAttribute,
                                                 multiplier: 1,
                                                 constant: 20)
        
        rightImageView.addConstraints([rightImageWidth, rightImageHeight])
        
        
        let rightImageRight = NSLayoutConstraint(item: rightImageView,
                                                attribute: .right,
                                                relatedBy: .equal,
                                                toItem: self,
                                                attribute: .right,
                                                multiplier: 1,
                                                constant: -16)
        
        let rightImageCenter = NSLayoutConstraint(item: rightImageView,
                                                 attribute: .centerY,
                                                 relatedBy: .equal,
                                                 toItem: self,
                                                 attribute: .centerY,
                                                 multiplier: 1,
                                                 constant: 0)
        
        addConstraints([rightImageRight, rightImageCenter])
     }
}

extension CGColor {
    fileprivate var uiColor: UIKit.UIColor {
        return UIKit.UIColor(cgColor: self)
    }
}

extension UIImage {
    fileprivate func tintedImage(_ color: UIColor) -> UIImage {
        let blendMode:CGBlendMode = .destinationIn
        UIGraphicsBeginImageContextWithOptions(self.size, false, 0)
        color.setFill()
        let bounds = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
        UIRectFill(bounds)
        draw(in: bounds, blendMode: blendMode, alpha: 1)
        let tintedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return tintedImage!
    }
}