Abstractions

SaveDocument.kt

data class Document(
    val data: Byte[]
}

interface ExportDocument {
    fun export(document: Document)
}

class PngExportDocument : ExportDocument {
    override fun export(document: Document) = TODO("Export as Png")
}


class JpgExportDocument : ExportDocument {
    override fun export(document: Document) = TODO("Export as Jpg")
}

class Editor(
    private val exportDocument: ExportDocument
) {
   ... 
}