android kotlin - CountDownTimer start stop pause resume example

MainActivity.kt

package com.cfsuman.kotlinexamples

import android.content.Context
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
import android.os.CountDownTimer


class MainActivity : AppCompatActivity() {

    private var isPaused = false
    private var isCancelled = false
    private var resumeFromMillis:Long = 0

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

        val millisInFuture:Long = 50000
        val countDownInterval:Long = 1000


        // Count down timer start button
        button_start.setOnClickListener{
            // Start the timer
            timer(millisInFuture,countDownInterval).start()
            it.isEnabled = false
            button_stop.isEnabled = true
            button_pause.isEnabled = true

            isCancelled = false
            isPaused = false
        }


        // Count down timer stop/cancel button
        button_stop.setOnClickListener{
            // Start the timer
            isCancelled = true
            isPaused = false

            it.isEnabled = false
            button_start.isEnabled = true
            button_pause.isEnabled = false
        }


        // Count down timer pause button
        button_pause.setOnClickListener{
            isPaused = true
            isCancelled = false

            it.isEnabled = false
            button_start.isEnabled = false
            button_stop.isEnabled = false
            button_resume.isEnabled = true
        }


        // Count down timer resume button
        button_resume.setOnClickListener{
            // Resume the timer
            timer(resumeFromMillis,countDownInterval).start()

            isPaused = false
            isCancelled = false

            it.isEnabled = false
            button_pause.isEnabled = true
            button_start.isEnabled = false
            button_stop.isEnabled = true
        }
    }



    // Method to configure and return an instance of CountDownTimer object
    private fun timer(millisInFuture:Long,countDownInterval:Long):CountDownTimer{
        return object: CountDownTimer(millisInFuture,countDownInterval){
            override fun onTick(millisUntilFinished: Long){
                val timeRemaining = "Seconds remaining\n${millisUntilFinished/1000}"

                if (isPaused){
                    text_view.text = "${text_view.text}\nPaused"
                    // To ensure start timer from paused time
                    resumeFromMillis = millisUntilFinished
                    cancel()
                }else if (isCancelled){
                    text_view.text = "${text_view.text}\nStopped.(Cancelled)"
                    cancel()
                }else{
                    text_view.text = timeRemaining
                }
            }

            override fun onFinish() {
                text_view.text = "Done"
            }
        }

   }
}



// Extension function to show toast message
fun Context.toast(message: String) {
    Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/root_layout"
    android:background="#b8d7bf"
    android:padding="16dp"
    android:orientation="vertical"
    >
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_gravity="center_horizontal"
        >
        <Button
            android:id="@+id/button_start"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Start"
            />
        <Button
            android:id="@+id/button_stop"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Stop(Cancel)"
            android:enabled="false"
            />
        <Button
            android:id="@+id/button_pause"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Pause"
            android:enabled="false"
            />
        <Button
            android:id="@+id/button_resume"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Resume"
            android:enabled="false"
            />
    </LinearLayout>
    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#ff0011"
        android:layout_gravity="center_horizontal"
        android:textSize="25sp"
        android:layout_margin="25dp"
        android:gravity="center"
        />
</LinearLayout>