android kotlin - Vibrate phone programmatically

MainActivity.kt

package com.cfsuman.test

import android.content.Context
import android.graphics.Color
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*
import android.os.VibrationEffect
import android.os.Build
import android.os.Vibrator


class MainActivity : AppCompatActivity() {

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

        // Set the root layout background color
        root_layout.setBackgroundColor(if(hasVibrator)Color.GREEN else Color.RED)

        // Button click listener
        button.setOnClickListener{
            // Vibrate the phone programmatically
            vibrate()
        }
    }
}


/*
    *** documentation source developer.android.com ***

    VibrationEffect
        A VibrationEffect describes a haptic effect to be performed by a Vibrator. These effects
        may be any number of things, from single shot vibrations to complex waveforms.


        VibrationEffect createOneShot (long milliseconds, int amplitude)
            Create a one shot vibration. One shot vibrations will vibrate constantly
            for the specified period of time at the specified amplitude, and then stop.

        Parameters
            milliseconds long : The number of milliseconds to vibrate. This must be a positive number.
            amplitude int : The strength of the vibration. This must be a value between 1 and 255, or DEFAULT_AMPLITUDE.

        Returns
            VibrationEffect The desired effect.

*/

// Extension method to vibrate a phone programmatically
fun Context.vibrate(milliseconds:Long = 500){
    val vibrator = this.getSystemService(Context.VIBRATOR_SERVICE) as Vibrator

    // Check whether device/hardware has a vibrator
    val canVibrate:Boolean = vibrator.hasVibrator()

    if(canVibrate){
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            // void vibrate (VibrationEffect vibe)
            vibrator.vibrate(
                    VibrationEffect.createOneShot(
                            milliseconds,
                            // The default vibration strength of the device.
                            VibrationEffect.DEFAULT_AMPLITUDE
                    )
            )
        }else{
            // This method was deprecated in API level 26
            vibrator.vibrate(milliseconds)
        }
    }
}


// Extension property to check whether device has Vibrator
val Context.hasVibrator:Boolean
get() {
    val vibrator = this.getSystemService(Context.VIBRATOR_SERVICE) as Vibrator
    return vibrator.hasVibrator()
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:id="@+id/root_layout"
    >
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="80dp"
        android:text="Vibrate Phone"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>

AndroidManifest.xml [Permission]

<uses-permission android:name="android.permission.VIBRATE"/>