timer

import androidx.appcompat.app.AppCompatActivity

import android.os.Bundle

import android.os.Handler

import android.os.SystemClock

import android.widget.Button

import androidx.core.app.ComponentActivity

import androidx.core.app.ComponentActivity.ExtraData

import androidx.core.content.ContextCompat.getSystemService

import android.icu.lang.UCharacter.GraphemeClusterBreak.T

import android.widget.TextView

import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

private var handler: Handler? = null

private var seconds = 0

private var minutes = 0

private var milliSeconds = 0

private var milliSecondTime = 0L

private var startTime = 0L

private var timeBuff = 0L

private var updateTime = 0L

private lateinit var textView: TextView

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

val button = findViewById<Button>(R.id.button)

textView = findViewById(R.id.text)

handler = Handler()

button.setOnClickListener {

startTime = SystemClock.uptimeMillis()

handler!!.postDelayed(runnable, 0)

}

}

private var runnable: Runnable = object : Runnable {

override fun run() {

milliSecondTime = SystemClock.uptimeMillis() - startTime

updateTime = timeBuff + milliSecondTime

seconds = (updateTime / 1000).toInt()

minutes = seconds / 60

seconds %= 60

milliSeconds = (updateTime % 1000).toInt()

textView.setText(

"" + minutes + ":"

+ String.format("%02d", seconds) + ":"

+ String.format("%03d", milliSeconds)

)

handler?.postDelayed(this, 0)

}

}

}