enumProtocol.swift

public enum SelectionType {
    case filter
    case size
}

public protocol BaseSelectionType {
    var selectionType: SelectionType { get }
}

public enum FilterType: String, BaseSelectionType {
    case colorDocument
    case blackAndWhite
    case colorPhoto
    case greyscale
    
    public var selectionType: SelectionType {
        return SelectionType.filter
    }
}

public enum SizeType: String, BaseSelectionType {
    case originalSize
    case a4
    case a5
    case bCard
    case letter
    case legal
           
    public var selectionType: SelectionType {
        return SelectionType.size
    }
}