android kotlin - TimePicker example

MainActivity.kt

package com.cfsuman.kotlintutorials

import android.os.Bundle
import android.widget.*
import androidx.appcompat.app.AppCompatActivity
import kotlin.random.Random


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Get the widgets reference from XML layout
        val textView = findViewById<TextView>(R.id.textView)
        val timePicker = findViewById<TimePicker>(R.id.timePicker)
        val buttonGet = findViewById<Button>(R.id.buttonGet)
        val buttonSet = findViewById<Button>(R.id.buttonSet)
        val buttonToggle = findViewById<Button>(R.id.buttonToggle)


        // Set a time change listener for time picker widget
        timePicker.setOnTimeChangedListener{
                view,hourOfDay,minute->
            textView.text = "Time Changed ${getHourAMPM(hourOfDay)} " +
                    ": $minute ${getAMPM(hourOfDay)}"
        }


        // Set a random time
        buttonSet.setOnClickListener{
            // Set a random time
            setPickerTime(timePicker)
        }


        // Set a click listener for get time button widget
        buttonGet.setOnClickListener{
            // Display the picker current time on text view
            textView.text = "Selected Time : ${getPickerTime(timePicker)}"
        }


        // Toggle time picker 24 hour view
        buttonToggle.setOnClickListener{
            if(timePicker.is24HourView){
                timePicker.setIs24HourView(false)
            }else{
                timePicker.setIs24HourView(true)
            }
        }
    }


    // Get time picker current time as string
    private fun getPickerTime(timePicker: TimePicker):String{
        val hour = timePicker.hour
        val minute = timePicker.minute
        return "${getHourAMPM(hour)} : $minute ${getAMPM(hour)}"
    }


    // Get AM PM value from provided hour
    private fun getAMPM(hour:Int):String{
        return if(hour>11)"PM" else "AM"
    }


    // Get hour for AM PM time format
    private fun getHourAMPM(hour:Int):Int{
        // Return the hour value for AM PM time format
        var modifiedHour = if (hour>11)hour-12 else hour
        if (modifiedHour == 0){modifiedHour = 12}
        return modifiedHour
    }


    // Set time picker random time
    private fun setPickerTime(timePicker: TimePicker){
        // Get random time
        // Kotlin random range(inclusive,exclusive)
        val hour = Random.nextInt(0,24)
        val minute = Random.nextInt(0,60)

        timePicker.hour = hour
        timePicker.minute = minute
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/rootLayout"
    android:background="#DCDCDC"
    android:padding="24dp">

    <TextView
        android:id="@+id/textView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:padding="16dp"
        android:background="#E6E5E5"
        android:fontFamily="sans-serif"
        android:textSize="20sp"
        android:textAlignment="center"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TimePicker
        android:id="@+id/timePicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:timePickerMode="spinner"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <Button
        android:id="@+id/buttonGet"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="Get Time"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/timePicker" />

    <Button
        android:id="@+id/buttonSet"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="Set Time"
        app:layout_constraintBottom_toBottomOf="@+id/buttonGet"
        app:layout_constraintStart_toEndOf="@+id/buttonGet" />

    <Button
        android:id="@+id/buttonToggle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="Toggle 24"
        app:layout_constraintBottom_toBottomOf="@+id/buttonSet"
        app:layout_constraintStart_toEndOf="@+id/buttonSet" />

</androidx.constraintlayout.widget.ConstraintLayout>