IntRangeAdapter: A BaseAdapter that allows for easy handling of an integer range. Allows the minimum or maximum to be changed at any time more easily and efficiently than an ArrayAdapter can.

IntRangeAdapter.kt

import android.content.Context
import android.support.annotation.IntegerRes
import android.util.Log
import android.view.*
import android.widget.BaseAdapter
import android.widget.TextView

class IntRangeAdapter(val context: Context,
                      @IntegerRes var resource: Int,
                      @IntegerRes var dropDownResource: Int,
                      minInclusive_: Int,
                      maxInclusive_: Int)
    : BaseAdapter()
{
    var minInclusive = minInclusive_
        set(value) {
            field = value
            notifyDataSetChanged()
        }
    var maxInclusive = maxInclusive_
        set(value) {
            field = value
            notifyDataSetChanged()
        }
    val inflater: LayoutInflater = LayoutInflater.from(context)
    val originalMin: Int
    val originalMax: Int

    init {
        originalMax = maxInclusive_
        originalMin = minInclusive_
    }

    override fun getItem(position: Int): Int = minInclusive + position

    override fun hasStableIds(): Boolean = true

    override fun getItemId(position: Int): Long = minInclusive.toLong() + position

    override fun getCount(): Int = maxInclusive - minInclusive + 1

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
        return createViewFromResource(position, convertView, parent, resource)
    }

    override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup): View {
        return createViewFromResource(position, convertView, parent, dropDownResource)
    }

    fun getPosition(value: Int): Int {
        if (value < minInclusive || value > maxInclusive)
            throw IllegalArgumentException("value $value not in range of adapter [$minInclusive, $maxInclusive]")
        return value - minInclusive
    }

    private fun createViewFromResource(position: Int, convertView: View?, parent: ViewGroup, resource: Int): View {
        val view = convertView ?: inflater.inflate(resource, parent, false)
        val textView: TextView
        try {
            textView = view as TextView
        } catch (e: ClassCastException) {
            Log.e("IntRangeAdapter", "You must supply a resource ID for a TextView")
            return view
        }

        val item = getItem(position)
        textView.text = item.toString()

        return view
    }

}