playground.swift

protocol CanvasItem: Codable
{
    var scale: CGFloat { get set }
}

class StickerItem: CanvasItem
{
    var scale: CGFloat = 0.0
    var stickerName : String = ""
}

class ShapeItem: CanvasItem
{
    var scale: CGFloat = 0.0
    var colorHex = ""
}


class CanvasShapeView: UIView {
    let shapeItem: ShapeItem
    init(shapeItem: ShapeItem) {
        self.shapeItem = shapeItem
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}

class CanvasStickerView: UIView {
    let stickerItem: StickerItem
    init(stickerItem: StickerItem) {
        self.stickerItem = stickerItem
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}