android kotlin - Media player SeekBar example

MainActivity.kt

package com.cfsuman.kotlintutorials

import android.app.Activity
import android.content.Context
import android.media.MediaPlayer
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.widget.*


class MainActivity : Activity() {
    private lateinit var player: MediaPlayer
    private lateinit var runnable:Runnable
    private var handler: Handler = Handler(Looper.getMainLooper())
    lateinit var seekBar:SeekBar
    lateinit var tvPass:TextView
    lateinit var tvDue:TextView

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

        // get the widgets reference from XML layout
        val buttonStart = findViewById<Button>(R.id.buttonStart)
        val buttonStop = findViewById<Button>(R.id.buttonStop)
        seekBar = findViewById(R.id.seekBar)
        val tvDuration = findViewById<TextView>(R.id.tvDuration)
        tvPass = findViewById(R.id.tvPass)
        tvDue = findViewById(R.id.tvDue)


        // Start the media player
        buttonStart.setOnClickListener{
            player = MediaPlayer.create(
                applicationContext,
                R.raw.test_sound
            )

            player.start()
            tvDuration.text = "${player.seconds} sec"
            initializeSeekBar()

            it.isEnabled = false
            buttonStop.isEnabled = true

            player.setOnCompletionListener {
                buttonStop.isEnabled = false
                buttonStart.isEnabled = true
                toast("end")
            }
        }


        // Stop the media player
        buttonStop.setOnClickListener{
            if(player.isPlaying){
                player.stop()
                player.reset()
                player.release()
                handler.removeCallbacks(runnable)

                it.isEnabled = false
                buttonStart.isEnabled = true
            }
        }


        // Seek bar change listener
        seekBar.setOnSeekBarChangeListener(
            object : SeekBar.OnSeekBarChangeListener {
            override fun onProgressChanged(
                seekBar: SeekBar, i: Int, b: Boolean) {
                if (b) {
                    player.seekTo(i * 1000)
                }
            }

            override fun onStartTrackingTouch(seekBar: SeekBar) {
            }

            override fun onStopTrackingTouch(seekBar: SeekBar) {
            }
        })
    }


    // Method to initialize seek bar and audio stats
    private fun initializeSeekBar() {
        seekBar.max = player.seconds

        runnable = Runnable {
            seekBar.progress = player.currentSeconds

            tvPass.text = "${player.currentSeconds} sec"
            val diff = player.seconds - player.currentSeconds
            tvDue.text = "$diff sec"

            handler.postDelayed(runnable, 1000)
        }
        handler.postDelayed(runnable, 1000)
    }
}



// Extension property to get
// media player duration in seconds
val MediaPlayer.seconds:Int
    get() {
        return this.duration / 1000
    }


// Extension property to get
// media player current position in seconds
val MediaPlayer.currentSeconds:Int
    get() {
        return this.currentPosition/1000
    }


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

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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#DCDCDC"
    android:padding="24dp">

    <TextView
        android:id="@+id/tvDuration"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        app:layout_constraintBottom_toTopOf="@+id/seekBar"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        tools:text="Duration" />

    <TextView
        android:id="@+id/tvDue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="24dp"
        app:layout_constraintBottom_toTopOf="@+id/seekBar"
        app:layout_constraintEnd_toEndOf="@+id/seekBar"
        tools:text="Due" />

    <TextView
        android:id="@+id/tvPass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        app:layout_constraintBottom_toTopOf="@+id/seekBar"
        app:layout_constraintStart_toStartOf="@+id/seekBar"
        tools:text="Pass" />

    <SeekBar
        android:id="@+id/seekBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:saveEnabled="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/buttonStart"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="Start"
        app:layout_constraintEnd_toStartOf="@+id/buttonStop"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/seekBar" />

    <Button
        android:id="@+id/buttonStop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Stop"
        app:layout_constraintBottom_toBottomOf="@+id/buttonStart"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/buttonStart" />

</androidx.constraintlayout.widget.ConstraintLayout>