In my application I have one fragment and in this fragment I have one recyclerview and 2 button.
Button 1 is Select all and button 2 is Deselect all.

I write below codes for recyclerview:

`

private lateinit var binding: ItemDayMyBinding

private lateinit var context: Context

private val TYPE_HEADER = 0
private val TYPE_DAY = 1
private var firstDayDayOfWeek = 0
private var totalDays = 0
private var todayPosition = -1

private val addedDateList = mutableListOf<PersianDate>()
private val removedDateList = mutableListOf<PersianDate>()

private val selectedDays = mutableListOf<DayEntity>()

init {
    firstDayDayOfWeek = items[0].dayOfWeek
    totalDays = items.size
}

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

override fun getItemCount() = 7 * 7

override fun getItemViewType(position: Int): Int {
    return if (isPositionHeader(position)) {
        TYPE_HEADER
    } else {
        TYPE_DAY
    }
}

override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    holder.bind(position)
    holder.setIsRecyclable(false)
}

inner class ViewHolder : RecyclerView.ViewHolder(binding.root) {
    //Bind data
    fun bind(pos: Int) {
        binding.apply {
            var position = pos
            position  = 6 - (position % 7) * 2
            //Check
            if (totalDays < position - 6 - firstDayDayOfWeek) {
                return
            } else {
                //Day
                if (!isPositionHeader(position)) {
                    if (position - 7 - firstDayDayOfWeek >= 0) {
                        val day = items[position - 7 - firstDayDayOfWeek]

                        dayTxt.isVisible = true
                        //Day text options
                        dayTxt.text = day.num
                        dayTxt.setTextColor(ContextCompat.getColor(context, R.color.black))
                        //Holiday
                        if (day.isHoliday) {
                            dayTxt.setTextColor(ContextCompat.getColor(context, R.color.mystic))
                        } else {
                            dayTxt.setTextColor(ContextCompat.getColor(context, R.color.black))
                            //Today
                            if (day.isToday) {
                                todayPosition = position
                            }
                            //Previous of today
                            if (position < todayPosition) {
                                dayTxt.setTextColor(ContextCompat.getColor(context, R.color.spanishGray))
                            } else {
                                dayTxt.setTextColor(ContextCompat.getColor(context, R.color.black))
                            }
                        }
                    } else {
                        dayTxt.isVisible = false
                    }
                } else {
                    //Header
                    dayTxt.text = NAME_OF_DAYS_OF_WEEK_NAME[position]
                    dayTxt.setTextColor(ContextCompat.getColor(context, R.color.weldonBlue))
                }
            }
        }
    }
}

private fun isPositionHeader(position: Int) = position < 7

I want when click on select all button, select all today and next days.
Not previous days!

Searched in stackoverflow and find this:

`

ArrayList<Item> selected = new ArrayList<Item>();
ArrayList<Item> items = new ArrayList<Item>();

public void selecteAll() {
    selected.clear();
    selected.addAll(items);
    notifyDataSetChanged();
}

public void clearAll() {
    selected.clear();
    notifyDataSetChanged();
}

public void bindView() {
    Item item = items.get(position);

    if(selected.contains(item) {
        // Do selected action
    } else {
       // Non selecetd ctions
    }
}

`

In this solution just select all of items, but I want just select today and next days!

How can I it?

CodePudding user response：

Not getting exactly what you have in Item and other data but yes below code can give you hint what you can do

I want when click on select all button, select all today and next days. 

As per your requirement , you first need to determine that you need to perform selection operation or not and from where

So first you declare one boolean in your adapter class

private boolean needToSelectDays = false

after declaring it in adapter , you can make change in selectAll function like this

public void selecteAll() {
    needToSelectDays = true
    notifyDataSetChanged();
}

public void clearAll() {
    needToSelectDays = false
    notifyDataSetChanged();
}

in above code we are managing boolean variable only .. now it is time of use it and as per your code , you are binding data in ViewHolder class so you can add this code within your existing code

fun bind(pos: Int) {
   // your existing code
   if(needToSelectDays && dayGettingFromItem >= currentDay){
      // you can write here logic of selecting date
   }else{
     // you can write here logic of unselecting dat
   }
}

hope it will help you

CodePudding user response：

Jacson

When you create adapter for recycler view then you pass list of model of items so just create one variable like isSelected = false

on select all button click change all item model to selected is true and for deselect all button click for all item is selected is false

and if you need select only today and next days then set is selected true for only today and next day

after that notify dataset chenge so resule as you want