Creating Timer in Android

Hello guys, in this tutorial we are going to see how to create a timer and to do something when the timer reaches a particular time. So lets  do it.

Download Project 

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:background="#000000"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/timerValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/pauseButton"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="37dp"
        android:textSize="40sp"
        android:textColor="#ffffff"
        android:text="00:00:000" />

    <Button
        android:id="@+id/startButton"
        android:layout_width="90dp"
        android:layout_height="45dp"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_marginLeft="38dp"
        android:text="start" />

    <Button
        android:id="@+id/pauseButton"
        android:layout_width="90dp"
        android:layout_height="45dp"
        android:layout_alignBaseline="@+id/startButton"
        android:layout_alignBottom="@+id/startButton"
        android:layout_alignParentRight="true"
        android:layout_marginRight="38dp"
        android:text="pause" />

</RelativeLayout>

MainActivity.java

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {
    Button start, pause;
    TextView time;
    private long startTime = 0L;

    private Handler customHandler = new Handler();

    long timeInMilliseconds = 0L;
    long timeSwapBuff = 0L;
    long updatedTime = 0L;
    boolean stopTimer = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        start = (Button) findViewById(R.id.startButton);
        pause = (Button) findViewById(R.id.pauseButton);
        time = (TextView) findViewById(R.id.timerValue);
        start.setOnClickListener(this);
        pause.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.startButton:
            startTime = SystemClock.uptimeMillis();
            customHandler.postDelayed(updateTimerThread, 0);
            break;

        case R.id.pauseButton:
            timeSwapBuff += timeInMilliseconds;
            customHandler.removeCallbacks(updateTimerThread);
            break;
        }
    }

    private Runnable updateTimerThread = new Runnable() {

        public void run() {
            timeInMilliseconds = SystemClock.uptimeMillis() - startTime;

            updatedTime = timeSwapBuff + timeInMilliseconds;

            int secs = (int) (updatedTime / 1000);
            int mins = secs / 60;
            secs = secs % 60;
            int milliseconds = (int) (updatedTime % 1000);
            String localtime = "" + mins + ":" + String.format("%02d", secs)
                    + ":" + String.format("%03d", milliseconds);
            time.setText(localtime);
            if (mins == 1) {
                stopTimer = true;
                Toast.makeText(MainActivity.this, "You guys are awesome",
                        Toast.LENGTH_SHORT).show();
            }
            if (!stopTimer)
                customHandler.postDelayed(this, 0);
        }

    };

}