back_handler #

A Flutter plugin that provides double-tap back button functionality to exit the app with customizable toast messages, custom widgets, and flexible callbacks.

Features #

• Double-tap to exit: Prevents accidental app closure by requiring two back button presses
• **Customizable# back_handler

A Flutter plugin that provides double-tap back button functionality to exit the app with customizable toast messages.

Features #

• Double-tap to exit: Prevents accidental app closure by requiring two back button presses
• Customizable toast message: Set your own message that appears on first back press
• Configurable time frame: Adjust how long users have between presses (default: 2 seconds)
• Cross-platform support: Works on both Android and iOS
• Easy integration: Simple widget wrapper or manual implementation options

Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  back_handler: ^1.0.0

Then run:

flutter pub get

Usage #

Method 1: Using BackHandlerWidget (Recommended) #

Wrap your main content with BackHandlerWidget:

import 'package:back_handler/back_handler.dart';

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BackHandlerWidget(
        toastMessage: 'Press back again to exit',
        exitTimeFrame: Duration(seconds: 2),
        child: Scaffold(
          appBar: AppBar(title: Text('My App')),
          body: Center(child: Text('Hello World')),
        ),
      ),
    );
  }
}

Method 2: Using WillPopScope with BackHandler #

For more control, use WillPopScope with BackHandler.handleBackPress():

import 'package:back_handler/back_handler.dart';

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        // Customize settings before handling
        BackHandler.setToastMessage('Tap back again to close');
        BackHandler.setExitTimeFrame(Duration(seconds: 3));
        
        return await BackHandler.handleBackPress(context);
      },
      child: Scaffold(
        appBar: AppBar(title: Text('My App')),
        body: Center(child: Text('Content here')),
      ),
    );
  }
}

Method 3: Global Configuration #

Set global defaults that apply throughout your app:

void main() {
  // Set global defaults
  BackHandler.setToastMessage('Please press back again to exit');
  BackHandler.setExitTimeFrame(Duration(seconds: 2));
  
  runApp(MyApp());
}

API Reference #

BackHandlerWidget #

BackHandler Static Methods #

How It Works #

1. First back press: Shows toast message and starts timer
2. Second back press (within time frame): Exits the app
3. Timeout: If second press doesn't come within the time frame, the process resets

Platform-Specific Behavior #

• Android: Shows native Toast message + SnackBar
• iOS: Shows SnackBar only (iOS doesn't have native toast)

Example #

Check out the example app for a complete demonstration including:

• Custom toast messages
• Dynamic message updates
• Different usage patterns
• Visual feedback and instructions

Contributing #

Contributions are welcome! Please feel free to submit a Pull Request.

License #

This project is licensed under the MIT License - see the LICENSE file for details.

Issues and Feedback #

Please file issues and feedback on the GitHub repository.