PositionUtil.kt

object PositionUtil {

    fun computePositionalDataSourceEquivalent(position:Int, totalCount: Int): Int {
         val pageSize = DataSource.PAGE_SIZE //DataSource.PAGE_SIZE is the requested page size
        val initialLoadSize = DataSource.PAGE_SIZE * 3 //Default loadSize is 3 times the requested load size

        var pageStart = position / pageSize * pageSize

        // maximum start pos is that which will encompass end of list
        val maximumLoadPage = (totalCount - initialLoadSize + pageSize - 1) / pageSize * pageSize
        pageStart = Math.min(maximumLoadPage, pageStart)

        // minimum start position is 0
        pageStart = Math.max(0, pageStart)

        return pageStart
    }

}