CountDownTimer app is about setting a time that moves in reverse order as it shows the time left in the upcoming event. A CountDownTimer is an accurate timer that can be used for a website or blog to display the count down to any special event, such as a birthday or anniversary. Likewise, here let’s create an Android App to learn how to create a simple Countdown App. So let’s begin app creation step by step towards its completion.
Approach
Step 1: Create a New Project
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.
Step 2: Working with activity_main.xml file
In the activity_main.xml file add only a TextView to display the CountDownTimer. Below is the complete code for the activity_main.xml file.
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent" android:background="#fff" tools:context=".MainActivity"> <!-- Here adding a TextView to show countdown --> <TextView android:id="@+id/textView" android:layout_width="0dp" android:layout_height="0dp" android:background="?android:attr/detailsElementBackground" android:gravity="center_horizontal|center_vertical" android:text="TextView" android:textColor="@color/colorPrimary" android:textSize="36sp" android:textStyle="bold" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.0" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintVertical_bias="0.0" /> </androidx.constraintlayout.widget.ConstraintLayout> |
Step 3: Working with MainActivity.java file
Now In MainActivity.java file, create an object of TextView and map the components(TextView) with their id.
// Initializing thetextView
TextView textView;
textView = findViewById (R.id.textView);
Schedule a countdown until a time in the future, with regular notifications on intervals along the way. Example of showing a 50-second countdown in a text field:
new CountDownTimer(50000, 1000) {
public void onTick(long millisUntilFinished) {
// Used for formatting digit to be in 2 digits only
NumberFormat f = new DecimalFormat(“00”);
long hour = (millisUntilFinished / 3600000) % 24;
long min = (millisUntilFinished / 60000) % 60;
long sec = (millisUntilFinished / 1000) % 60;
textView.setText(f.format(hour) + “:” + f.format(min) + “:” + f.format(sec));
}
// When the task is over it will print 00:00:00 there
public void onFinish() {
textView.setText(“00:00:00”);
}
}.start();
The complete code for the MainActivity.java file is given below.
MainActivity.java
package org.gfg.countdowntimer; import android.os.Bundle; import android.os.CountDownTimer; import android.widget.TextView; import androidx.appcompat.app.AppCompatActivity; import java.text.DecimalFormat; import java.text.NumberFormat; public class MainActivity extends AppCompatActivity { // Initializing my textView TextView textView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textView = findViewById(R.id.textView); // Time is in millisecond so 50sec = 50000 I have used // countdown Interveal is 1sec = 1000 I have used new CountDownTimer(50000, 1000) { public void onTick(long millisUntilFinished) { // Used for formatting digit to be in 2 digits only NumberFormat f = new DecimalFormat("00"); long hour = (millisUntilFinished / 3600000) % 24; long min = (millisUntilFinished / 60000) % 60; long sec = (millisUntilFinished / 1000) % 60; textView.setText(f.format(hour) + ":" + f.format(min) + ":" + f.format(sec)); } // When the task is over it will print 00:00:00 there public void onFinish() { textView.setText("00:00:00"); } }.start(); } } |
Output: Run on Emulator
PulseCountDown
PulseCountDown in Android is an alternative to CountDownTimer. It is very easy to implement PulseCountDown instead of CountDownTimer because PulseCountDown provides a default layout with some beautiful animations. By default start value of PulseCountDown is 10 and the end value is 0. Suppose there needs a quiz app, and in that add time limit to answer a question there PulseCountDown can be used. To implement PulseCountDown please refer PulseCountDown in Android with Example.
Pulse Count Down
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