Add day range selection about materialdaypicker HOT 3 OPEN

class RangeSelectionMode(
    private val materialDayPicker: MaterialDayPicker
) : SelectionMode {

    override fun getSelectionStateAfterSelecting(lastSelectionState: SelectionState, dayToSelect: MaterialDayPicker.Weekday): SelectionState {
        return createRangedSelectionState(
            lastSelectionState = lastSelectionState,
            dayPressed = dayToSelect
        )
    }

    override fun getSelectionStateAfterDeselecting(lastSelectionState: SelectionState, dayToDeselect: MaterialDayPicker.Weekday): SelectionState {
        return createRangedSelectionState(
            lastSelectionState = lastSelectionState,
            dayPressed = dayToDeselect
        )
    }

    private fun createRangedSelectionState(lastSelectionState: SelectionState, dayPressed: MaterialDayPicker.Weekday): SelectionState {
        val previouslySelectedDays = lastSelectionState.selectedDays
        val orderedWeekdays = getWeekdaysOrderedForCurrentLocale()
        val ordinalsOfPreviouslySelectedDays = previouslySelectedDays.map { orderedWeekdays.indexOf(it) }

        val ordinalOfFirstDayInPreviousRange = ordinalsOfPreviouslySelectedDays.min()
        val ordinalOfLastDayInPreviousRange = ordinalsOfPreviouslySelectedDays.max()
        val ordinalOfSelectedDay = orderedWeekdays.indexOf(dayPressed)

        return when {
            ordinalOfFirstDayInPreviousRange == null || ordinalOfLastDayInPreviousRange == null -> {
                // We had no previous selection so just return the day pressed as the selection.
                SelectionState.withSingleDay(dayPressed)
            }
            ordinalOfFirstDayInPreviousRange == ordinalOfLastDayInPreviousRange && ordinalOfFirstDayInPreviousRange == ordinalOfSelectedDay -> {
                // User pressed the only day in the range selection. Return an empty selection.
                SelectionState()
            }
            ordinalOfSelectedDay == ordinalOfFirstDayInPreviousRange || ordinalOfSelectedDay == ordinalOfLastDayInPreviousRange -> {
                // User pressed the first or last item in range. Just deselect that item.
                lastSelectionState.withDayDeselected(dayPressed)
            }
            ordinalOfSelectedDay < ordinalOfFirstDayInPreviousRange -> {
                // User pressed a day on the left of the previous date range. Grow the starting point of the range to that.
                SelectionState(selectedDays = orderedWeekdays.subList(ordinalOfSelectedDay, ordinalOfLastDayInPreviousRange + 1))
            }
            else -> {
                // User pressed a day on the right of the start of the date range. Update the ending point to that position.
                SelectionState(selectedDays = orderedWeekdays.subList(ordinalOfFirstDayInPreviousRange, ordinalOfSelectedDay + 1))
            }
        }
    }

    private fun getWeekdaysOrderedForCurrentLocale(): List<MaterialDayPicker.Weekday> {
        return MaterialDayPicker.Weekday.getOrderedDaysOfWeek(materialDayPicker.locale)
    }
}

materialDayPicker.selectionMode = RangeSelectionMode(materialDayPicker)