// Set rounded wrap enable
numberPicker.setSelectorRoundedWrapPreferred(true)
// Set wheel item count
numberPicker.setWheelItemCount(5)
// Set wheel max index
numberPicker.setMax(1000)
// Set wheel min index
numberPicker.setMin(1000)
// Set selected text color
numberPicker.setSelectedTextColor(R.color.color_4_blue)
// Set unselected text color
numberPicker.setUnselectedTextColor(R.color.color_3_dark_blue)
// Set user defined adapter
numberPicker.setAdapter(WPDayPickerAdapter())

// OnValueChangeListener
val context = this
numberPicker.setOnValueChangeListener(object : OnValueChangeListener{
  override fun onValueChange(picker: WheelPicker, oldVal: String, newVal: String) {
    val out = String.format("Current: %s", newVal)
    Toast.makeText(context, out, Toast.LENGTH_SHORT).show()
  }
})

// Adapter sample 
/**
 * Custom wheel picker adapter for implementing a date picker
 */
class WPDayPickerAdapter : WheelAdapter {
    //get item value based on item position in wheel
    override fun getValue(position: Int): String {
        if (position == 0)
            return "Today"

        if(position == -1)
            return "Yesterday"

        if (position == 1)
            return "Tomorrow"

        val curDate = Date(System.currentTimeMillis())
        val rightNow = Calendar.getInstance()
        rightNow.time = curDate;
        rightNow.add(Calendar.DATE, position)
        
        val simpleDateFormat = SimpleDateFormat("MMM d, yyyy")
        return simpleDateFormat.format(rightNow.time)
    }

    //get item position based on item string value
    override fun getPosition(vale: String): Int {
        return 0
    }

    //return a string with the approximate longest text width, for supporting WRAP_CONTENT
    override fun getTextWithMaximumLength(): String {
        return "Mmm 00, 0000"
    }

    //return the maximum index
    override fun getMaxIndex(): Int {
        return Integer.MAX_VALUE
    }

    //return the minimum index
    override fun getMinIndex(): Int {
        return Integer.MIN_VALUE
    }
}