Simple time picker with custom minute interval.

CustomTimePicker.kt

package packageName

import android.app.AlertDialog
import android.content.Context
import android.view.Gravity
import android.widget.LinearLayout
import android.widget.NumberPicker
import java.time.LocalTime
import kotlin.math.roundToInt

@Suppress("FunctionName")
fun CustomTimePicker(
    context: Context,
    hour: Int? = null,
    minute: Int ? = null,
    interval: Int = 1,
    onTimeSelected: (hour: Int, minute: Int) -> Unit = { _, _ -> },
    onCancel: (() -> Unit)? = null,
): AlertDialog {
    val dialogView = LinearLayout(context).apply {
        orientation = LinearLayout.HORIZONTAL
        setPadding(50, 20, 50, 20)
        gravity = Gravity.CENTER
    }

    val now = LocalTime.now()
    val initialHour = hour ?: now.hour
    val rawMinute = minute ?: now.minute
    val initialMinute = (rawMinute.toDouble() / interval).roundToInt()

    val hourPicker = NumberPicker(context).apply {
        minValue = 0
        maxValue = 23
        value = initialHour
    }

    val minutePicker = NumberPicker(context).apply {
        minValue = 0
        maxValue = (60 / interval) - 1
        displayedValues = Array(60 / interval) { i -> String.format("%02d", i * interval) }
        value = initialMinute
    }

    dialogView.addView(hourPicker)
    dialogView.addView(minutePicker)

    return AlertDialog.Builder(context)
        .setView(dialogView)
        .setPositiveButton(android.R.string.ok) { _, _ ->
            val hour = hourPicker.value
            val minute = minutePicker.value * interval
            onTimeSelected(hour, minute)
        }
        .setNegativeButton(android.R.string.cancel) { _, _ ->
            onCancel?.invoke()
        }
        .create()
}