Essentially I just want a public class but with protected co kotlinlang #announcements

Essentially I just want a public class but with protected constructor (I understand this isn't possible in Kotlin) so that the only way to construct it is through the factory

Czar

04/11/2018, 5:49 PM

why would you think that it is impossible?

open class PublicClassProtectedConstructor protected constructor(/*...*/)

in your :java: example you missed that

Factory

extends

PublicClassProtectedConstructor

to be able to see the constructor 🙂

fred.deschenes

04/11/2018, 5:56 PM

I'd probably do something like this : https://gist.github.com/FredDeschenes/cb5a3c822f8b1396d0d291773977567c

Joel Armstrong

04/11/2018, 6:03 PM

The issue is that I have multiple different constructors within the factory with vastly different parameters. I'm building midi byte sequences; sometimes there are no parameters; sometimes I need a device ID; sometimes it takes a volume and patch number...

fred.deschenes

04/11/2018, 6:09 PM

you can still have multiple constructors

did your factory methods just get the arguments and just send them to a protected constructor?

Joel Armstrong

04/11/2018, 6:13 PM

The factory methods take the arguments and place them into a sequence of bytes. Often logic is involved

Then that is sent to the constructor

fred.deschenes

04/11/2018, 6:18 PM

class PublicClassProtectedConstructor private constructor(private val bytes: ByteArray) {
    companion object Factory {
        fun factory1(deviceId: String): PublicClassProtectedConstructor {
            val bytes = ByteArray(0) // Setup however
            return PublicClassProtectedConstructor(bytes)
        }

        fun factory2(volume: Int, patch: Int): PublicClassProtectedConstructor {
            val bytes = ByteArray(0) // Setup however
            return PublicClassProtectedConstructor(bytes)
        }
    }
}

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