Android Count Down Timer Example


In this sample application we will create a countdown timer in android using the CountDownTimer class .This is an example of showing a 30 second countdown in a TextView . We will update the TextView on every tick of the timer.The option to stop and restart the timer is also provided.

So let us start:

1.Create a new project File ->New -> Project ->Android ->Android Application Project. While creating the new project, name the activity as TimerActivity(TimerActivity.java) and layout as activity_timer.xml.

2.Now let us design the UI for the TimerActivity i.e activity_timer.xml with a textview and a button.

activity_timer.xml

 
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/bgi" >

<TextView
android:id="@+id/timer"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:paddingRight="10dip"
android:textSize="50dp" />

<Button
android:id="@+id/button"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:text="Start" />

</RelativeLayout>

3.Now in the TimerActivity we implement the count down timer by extending the CountDownTimer class.Press Ctrl+Shift+O for missing imports after typing the code.

TimerActivity.java

 
public class TimerActivity extends Activity implements OnClickListener {

 private CountDownTimer countDownTimer;
 private boolean timerHasStarted = false;
 private Button startB;
 public TextView text;
 private final long startTime = 30 * 1000;
 private final long interval = 1 * 1000;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_timer);
  startB = (Button) this.findViewById(R.id.button);
  startB.setOnClickListener(this);
  text = (TextView) this.findViewById(R.id.timer);
  countDownTimer = new MyCountDownTimer(startTime, interval);
  text.setText(text.getText() + String.valueOf(startTime / 1000));
 }

 @Override
 public void onClick(View v) {
  if (!timerHasStarted) {
   countDownTimer.start();
   timerHasStarted = true;
   startB.setText("STOP");
  } else {
   countDownTimer.cancel();
   timerHasStarted = false;
   startB.setText("RESTART");
  }
 }

 public class MyCountDownTimer extends CountDownTimer {
  public MyCountDownTimer(long startTime, long interval) {
   super(startTime, interval);
  }

  @Override
  public void onFinish() {
   text.setText("Time's up!");
  }

  @Override
  public void onTick(long millisUntilFinished) {
   text.setText("" + millisUntilFinished / 1000);
  }
 }

}
4.Run the project by rightclicking project Run as → android project.

Output:

The output of this example would be similar to the one as follows:

 




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