IBDesignable subclass of UIView

View.swift

import UIKit

@IBDesignable
public class View: UIView {
    // MARK: - Layer stuff
    @IBInspectable
    public var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
        }
    }

    // MARK: - IBInspectable border
    @IBInspectable
    public var borderColor: UIColor? {
        get {
            guard let color = layer.borderColor else { return nil }
            return UIColor(cgColor: color)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }

    @IBInspectable
    public var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    // MARK: - IBInspectable shadow

    @IBInspectable
    public var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.shadowRadius = newValue
        }
    }

    @IBInspectable
    public var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.shadowOpacity = newValue
        }
    }

    @IBInspectable
    public var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            layer.shadowOffset = newValue
        }
    }

    @IBInspectable
    public var shadowColor: UIColor? {
        get {
            guard let color = layer.shadowColor else { return nil }
            return UIColor(cgColor: color)
        }
        set {
            layer.shadowColor = newValue?.cgColor
        }
    }

    public func clear() {
        layer.cornerRadius = 0
        layer.borderColor = nil
        layer.borderWidth = 0
        layer.shadowRadius = 0
        layer.shadowOpacity = 0
        layer.shadowOffset = .zero
        layer.shadowColor = nil
    }

    public override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        layer.cornerRadius = cornerRadius
        layer.borderColor = borderColor?.cgColor
        layer.borderWidth = borderWidth
        layer.shadowRadius = shadowRadius
        layer.shadowOpacity = shadowOpacity
        layer.shadowOffset = shadowOffset
        layer.shadowColor = shadowColor?.cgColor
    }
}