6 June 2024 Leave a comment Tech-Help
In many Android applications, you might have encountered a pattern where the app requires the user to press the back button twice within a short interval to exit the application. This guide will walk you through implementing this feature in your Android application, ensuring a smooth user experience.
Overview
The double back press to exit functionality is not a built-in feature in Android. Instead, it is a custom implementation that you can add to your activity. The primary idea is to display a message (usually a Toast) when the back button is pressed for the first time and then exit the application if the back button is pressed again within a specified time interval.
Implementation
We will provide you with a step-by-step implementation in both Java and Kotlin. The following code snippets demonstrate how to achieve this functionality.
Java Implementation
private boolean doubleBackToExitPressedOnce = false;
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
}
Kotlin Implementation
private var doubleBackToExitPressedOnce = false
override fun onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed()
return
}
this.doubleBackToExitPressedOnce = true
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show()
Handler(Looper.getMainLooper()).postDelayed({
doubleBackToExitPressedOnce = false
}, 2000)
}
Explanation
The implementation involves setting a boolean flag doubleBackToExitPressedOnce to true when the back button is pressed for the first time. A Toast message is displayed to inform the user to press the back button again to exit. A Handler is used to reset the flag after 2 seconds, allowing the user to exit the application if the back button is pressed again within this time frame.
Alternative Approaches
While the above method is widely used, there are alternative approaches that you can consider:
- Using
System.currentTimeMillis()to measure the time interval between two back presses and exit if the second press is within the specified time frame. - Using a Snackbar instead of a Toast for a more modern look.
Example with System.currentTimeMillis()
private static final int TIME_INTERVAL = 2000; // # milliseconds
private long mBackPressed;
@Override
public void onBackPressed() {
if (mBackPressed + TIME_INTERVAL > System.currentTimeMillis()) {
super.onBackPressed();
return;
} else {
Toast.makeText(getBaseContext(), "Tap back button in order to exit", Toast.LENGTH_SHORT).show();
}
mBackPressed = System.currentTimeMillis();
}
Enhancing Your App with Repeato
Implementing and testing features like the double back press to exit can be time-consuming. This is where Repeato, a No-code test automation tool for iOS and Android, can significantly streamline your process. Repeato allows you to create, run, and maintain automated tests for your apps quickly and efficiently. With its computer vision and AI capabilities, Repeato ensures that your tests are not only reliable but also easy to update and maintain.
By integrating Repeato into your development workflow, you can focus more on creating great features and less on the repetitive task of writing and maintaining test scripts. Repeato’s intuitive interface allows even non-technical team members to contribute to the testing process, enhancing collaboration and productivity.
For more details on how to get started with Repeato, check our Getting Started guide.
