class MemberStatisticPagerAdapter(
    fm: FragmentManager,
    behavior: Int
) : BaseFragmentStatePagerAdapter(fm, behavior) {

    private var data: List<MemberStatistic>? = null

    fun setData(data: List<MemberStatistic>) {
        this.data = data
    }

    override fun getItem(position: Int): Fragment {
        return StatisticMemberFragment.newInstance(data!![position])
    }

    override fun getCount(): Int {
        return data?.size ?: throw IllegalStateException("No data in pager adapter")
    }

    companion object {
        private const val TAG = "MemberStatisticPagerAdapter"
    }
}



abstract class BaseFragmentStatePagerAdapter(
    fm: FragmentManager,
    behavior: Int
) : FragmentStatePagerAdapter(fm, behavior) {

    private val registeredFragments = SparseArray<Fragment>()

    private val registeredFragmentsCount: Int
        get() = registeredFragments.size()

    override fun instantiateItem(container: ViewGroup, position: Int): Any {
        val fragment = super.instantiateItem(container, position) as Fragment
        registeredFragments.put(position, fragment)
        return fragment
    }

    override fun destroyItem(container: ViewGroup, position: Int, obj: Any) {
        registeredFragments.remove(position)
        super.destroyItem(container, position, obj)
    }

    fun getRegisteredFragment(position: Int): Fragment {
        return registeredFragments.get(position)
    }

    abstract override fun getItem(position: Int): Fragment

    abstract override fun getCount(): Int

}