如何最佳地存储编辑器数据？

Question

我需要在数周和数天内实现计划编辑功能。在应用中，计划的每一天都是Fragment内的ViewPager。现在，我尝试将所选项目存储在特殊类的主机Activity中：

class LessonEditor {

    var mode: Mode = Mode.NONE
        private set(value) {
            field = value
            callbacks.forEach(fun(item: Callback) {
                item.onChangeEditMode(value)
            })
        }
    private var callbacks: MutableList<Callback> = mutableListOf()
    private var editList: MutableList<Int>? = null
    private var createList: MutableList<CreateItem>? = null

    fun create() {
        editList = mutableListOf()
        createList = mutableListOf()
        callbacks.forEach(fun(item: Callback) {
            item.onCreateEditor()
        })
    }

    fun destroy() {
        callbacks.forEach(fun(item: Callback) {
            item.onDestroyEditor()
        })
        editList?.clear()
        createList?.clear()
        editList = null
        createList = null
        mode = Mode.NONE
    }

    fun add(id: Int): Boolean {

        when (mode) {
            Mode.CREATE -> return false
            Mode.NONE -> mode = Mode.EDIT_ONE
            Mode.EDIT_ONE -> mode = Mode.EDIT_FEW
            else -> {}
        }

        return editList?.add(id)?: false
    }

    fun subscribe(callback: Callback) {
        callbacks.add(callback)
    }

    fun unsubscribe(callback: Callback) {
        callbacks.remove(callback)
    }

    fun add(week: Int, day: Day, order: Int): Boolean {

        if (Mode.EDIT_ONE == mode || Mode.EDIT_FEW == mode) {
            return false
        }

        if (Mode.NONE == mode) {
            mode = Mode.CREATE
        }

        return createList?.add(CreateItem(week, day, order))?: false
    }

    fun remove(id: Int) {

        if (Mode.NONE == mode || Mode.CREATE == mode) {
            return
        }

        if (editList?.remove(id) == true) {

            if (editList?.isEmpty() == true) {
                mode = Mode.NONE
            } else if (1 == editList?.size) {
                mode = Mode.EDIT_ONE
            }
        }
    }

    fun remove(week: Int, day: Day, order: Int) {

        if (Mode.CREATE != mode) {
            return
        }

        if (createList?.remove(CreateItem(week,day, order)) == true &&
                createList?.isEmpty() == true) {
            mode = Mode.NONE
        }
    }

    data class CreateItem(var week: Int, var day: Day, var order: Int)

    enum class Mode {
        NONE, CREATE, EDIT_ONE, EDIT_FEW
    }

    interface Callback {
        fun onCreateEditor()
        fun onDestroyEditor()
        fun onChangeEditMode(mode: Mode)
    }
}

这是一个草稿模型。主要思想是主要活动控制着LessonEditor的生命周期，并且Fragment s可以从实现LessonEditor.Callback的编辑器中进行订阅和退订。但是我的解决方案并不方便，因为我需要复制数据，因为Fragment需要将适配器的数据保存在savedInstanceState中，并且当用户再次选择该片段时，它需要与之同步状态LessonEditor。

是否有一些更优雅的方式可以通过片段进行编辑？