[Android / Kotlin ] ViewPager2 로 달력만들기 2편

 

 

1편에 이어서 2편을 작성해 보겠습니다. 

 

CalendarAdapter를 생성해서 CalendarFragment에서의 리사이클러뷰 어댑터를 연결시켜 줍니다. 

class CalendarAdapter(private val context: Context,private val calendarLayout: LinearLayout,private val date: Date) : RecyclerView.Adapter<CalendarAdapter.CalendarItemHolder>() {

    var dataList: ArrayList<Int> = arrayListOf()
    var dateCalendar= DateCalendar(date)

    init {
        dateCalendar.initBaseCalendar()
        dataList = dateCalendar.dateList
    }

    override fun onBindViewHolder(holder: CalendarItemHolder, position: Int) {

        val h = calendarLayout.height / 6
        holder.itemView.layoutParams.height = h

        holder.bind(dataList[position], position, context)

    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CalendarItemHolder {
        val binding = ItemCalendarDateListBinding.inflate(LayoutInflater.from(parent.context), parent, false)
        return CalendarItemHolder(binding)
    }

    override fun getItemCount(): Int = dataList.size

    inner class CalendarItemHolder(private val binding : ItemCalendarDateListBinding) : RecyclerView.ViewHolder(binding.root) {

        fun bind(data: Int, position: Int, context: Context) {
            val firstDateIndex = dateCalendar.prevTail
            val lastDateIndex = dataList.size - dateCalendar.nextHead - 1
            binding.itemCalendarDateText.text = data.toString()

            if (position < firstDateIndex || position > lastDateIndex) {
                binding.itemCalendarDateText.alpha = 0.4f
            }else{
                binding.itemCalendarDateText.alpha = 1f
            }
        }

    }
}

 

 

 

Class DateCalendar 생성. 

class DateCalendar(date: Date) {

    private val DAYS_OF_WEEK = 7
    private val LOW_OF_CALENDAR = 6
    private val calendar = Calendar.getInstance()

    var prevTail = 0
    var nextHead = 0
    var currentMaxDate = 0
    var dateList = arrayListOf<Int>()

    init {
        calendar.time = date
    }

    fun initBaseCalendar() {
        makeMonthDate()
    }

    private fun makeMonthDate() {
        dateList.clear()
        calendar.set(Calendar.DATE, 1)
        currentMaxDate = calendar.getActualMaximum(Calendar.DAY_OF_MONTH)
        prevTail = calendar.get(Calendar.DAY_OF_WEEK) - 1
        makePrevTail(calendar.clone() as Calendar)
        makeCurrentMonth(calendar)
        nextHead = LOW_OF_CALENDAR * DAYS_OF_WEEK - (prevTail + currentMaxDate)
        makeNextHead()
    }

    private fun makePrevTail(calendar: Calendar) {
        calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) - 1)
        val maxDate = calendar.getActualMaximum(Calendar.DATE)
        var maxOffsetDate = maxDate - prevTail
        for (i in 1..prevTail) dateList.add(++maxOffsetDate)
    }

    private fun makeCurrentMonth(calendar: Calendar) {
        for (i in 1..calendar.getActualMaximum(Calendar.DATE)) dateList.add(i)
    }

    private fun makeNextHead() {
        var date = 1
        for (i in 1..nextHead) dateList.add(date++)
    }

}

 

 

 

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